Download 2-3 Blood Clotting

Ministry of higher education and scientific research
Foundation of technical education
Learning package in filed
Medical physiology
( theoretical part )
Presented to the first class students
Of
Institute of medical technology – Baghdad
Department of community health
Designed by
Dr. Rawaa adnan faraj
2009 -2010
1
A: Over view
1- Target population :
This learning package had been designed to the first class students in
the Community Health Dept. of the Institute of Medical Technology –
Baghdad.
2- Rationale:
This learning package will aid those who want to learn the basic
physiology concepts that apply to the health field. It is also intended for
students who have little or no science background.
The student will discover, the concise nature of those units has
made each sentence significant. Thus, the reader will be intellectually
challenged to learn each new concept as it is presented.
It is my hope that the students will enjoy their study of physiology
and be motivated to further explore this fascinating field, especially as it
relates to their occupations.
3- general target :
The students are able to know and understand physiology and functions
and structures of human body
2
Unit one
Physiology
Human physiology is the science of the mechanical, physical, and biochemical
functions of humans in good health, their organs, and the cells of which they
are composed. The principal level of focus of physiology is at the level of
organs and systems. Most aspects of human physiology, and animal
experimentation has provided much of the foundation of physiological
knowledge. Anatomy and physiology are closely related fields of study:
anatomy, the study of form, and physiology, the study of function,. The word
physiology is form Ancient Greek: φύσις, physis, "nature, origin"; and -
λογία, -logia, "study of"
1-1 The blood
Blood is the life-maintaining fluid that circulates through the body's:- Heart. ,
arteries ,veins , capillaries
The blood consists of a suspension of special cells in a liquid called plasma. In
an adult man, the blood is about 1/12th of the body weight and this
corresponds to 5-6 liters. Blood consists of 55 % plasma, and 45 % by cells
called formed elements.
The blood performs a lot of important functions. By means of the hemoglobin
contained in the erythrocytes, it carries oxygen to the tissues and collects the
carbon dioxide (CO2). It also conveys nutritive substances (e.g. amino acids,
sugars, mineral salts) and gathers the excreted material which will be
eliminated through the renal filter. The blood also carries hormones, enzymes
and vitamins. It performs the defense of the organism by mean of the
phagocitic activity of the leukocytes, the bactericidal power of the serum and
the immune response of which the lymphocytes are the protagonists.
2-1 Functions of blood
1- Transports :(Dissolved gases (e.g. oxygen, carbon dioxide), waste products of
metabolism (e.g. water, urea ), hormones ,enzymes Nutrients (such as glucose,
amino acids, micro-nutrients (vitamins & minerals), fatty acids, glycerol);
Plasma proteins (associated with defense, such as blood-clotting and antibodies); Blood cells (incl. white blood cells 'leucocytes', and red blood cells
'erythrocytes and platelets
2- Maintains Body Temperature.
3- Control pH ( The pH of blood must remain in the range 6.8 to
7.4, otherwise it begins to damage cells)
4- Removes toxins from the body
(The kidneys filter all of the blood in the body (approx. 8 pints), 36 times
every 24
hours. Toxins removed from the blood by the kidneys leave the
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body in the urine.
(Toxins also leave the body in the form of sweat.)
5- Regulation of Body Fluid Electrolytes
Excess salt is removed from the body in urine, which may contain around 10g
salt per day(such as in the cases of people on western diets containing more
salt than the body requires
3-1 The plasma
The plasma is a slightly alkaline fluid, with a typical yellowish
color. It consists of 90 % water and 10% dry matter. Nine parts of
it are made up by organic substances, whereas one part is made
up by minerals. These organic substances are composed of
(glucose), lipids (cholesterol, triglycerides, phospholipids, lecithin,
fats), proteins (globulins, albumins, fibrinogen), glycoproteins,
hormones (gonadothropins, erythropoietin, thrombopoietin),
amino acids and vitamins. The mineral substances are dissolved in
ionic form, that is dissociated into positive and negative ions.
4-1 the blood cells
1-
Red blood cells (erythrocytes)
The erythrocytes are the most numerous blood cells i.e. about 4-6
millions/mm3. They are also called red cells. In man and in all mammals,
erythrocytes are devoid of a nucleus and have the shape of a biconcave lens.
they have a nucleus. The red cells are rich in hemoglobin, a protein able to
bind in a faint manner to oxygen. In the red cells of the mammalians, the lack
of nucleus allows more room for hemoglobin and the biconcave shape of these
cells raises the surface and cytoplasmic volume ratio. The mean life of
erythrocytes is about 120 days. When they come to the end of their life, they
are retained by the spleen where they are phagocyted by macrophages.
5-1 Functions of red blood cells
The primary function of red blood cells, or erythrocytes, is to carry oxygen
and carbon dioxide. Hemoglobin (Hgb) is an important protein in the red blood
cells that carries oxygen from the lungs to all parts of our body.
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Test –No. 1
Enumerate the functions of blood
Test – No. 2
What is the main functions of erythrocyte
4
Unit two
1-2 White blood cells (leukocytes)
Leukocytes, or white cells, are responsible for the defense of the organism. In
the blood, they are much less numerous than red cells. The density of the
leukocytes in the blood is 5000-7000 /mm3. Leukocytes divide in two
categories: granulocytes and lymphoid cells or agranulocytes. The term
granulocyte is due to the presence of granules in the cytoplasm of these cells.
In the different types of granulocytes, the granules are different and help us to
distinguish them. In fact, these granules have a different affinity towards
neutral, acid or basic stains and give the cytoplasm different colors. So,
granulocytes distinguish themselves in neutrophil, eosinophil (or acidophil)
and basophil. The lymphoid cells, instead, distinguish themselves in
lymphocytes and monocytes. As we will see later, even the shape of the
nucleus helps us in the recognition of the leukocytes.
Each type of leukocyte is present in the blood in different proportions:
neutrophil 50 - 70 %
eosinophil 2 - 4 %
basophil 0,5 - 1 %
lymphocyte 20 - 40 %
monocyte 3 - 8 %
2-2 Functions of white blood cells


The primary function of white blood cells, or leukocytes, is to fight
infection. There are several types of white blood cells and each has its
own role in fighting bacterial, viral, fungi, and parasitic infections. Types
of white blood cells that are most important for helping protect the body
from infection and foreign and Help heal wounds not only by fighting
infection but also by ingesting matter such as dead cells, tissue debris
and old red blood cells.
Are our protection from foreign bodies that enter the blood stream, such
as allergens.
Types of white blood cells include:
A granulocytes


Lymphocytes.
Monocytes.
(granulocytes).



Eosinophils.
Basophils.
Neutrophils
5
1- Neutrophils
are very active in phagocyting bacteria and are present in large amount in
the pus of wounds. Unfortunately, these cells are not able to renew the
lysosomes used in digesting microbes and dead after having phagocyted a
few of them.
2- Eosinophils
attack parasites and phagocyte antigen-antibody complexes
3- Basophil
secrete anti-coagulant and vasodilatory substances as histamines and
serotonin. Even if they have a phagocytory capability, their main function is
secreting substances which mediate the hypersensitivity reaction
Lymphocytes :- T – lymphocyte B – lymphocyte
are cells which, besides being present in the blood, populate the lymphoid
tissues and organs too, as well as the lymph circulating in the lymphatic
vessel. The lymphoid organs include thymus, bone marrow ,spleen, lymphoid
nodules, palatine tonsils, Peyer's patches and lymphoid tissue of respiratory
and gastrointestinal tracts.
Monocytes
are the precursors of macrophages. They are larger blood
cells, which after attaining maturity in the bone marrow,
enter the blood circulation where they stay for 24-36 hours.
Then they migrate into the connective tissue, where they
become macrophages and move within the tissues. In the
presence of an inflammation site, monocytes quickly
migrate from the blood vessel and start an intense
phagocytory activity. The role of these cells is not solely in
phagocytosis because they have also have an intense
secretory activity. They produce substances which have
defensive functions such as lysozime, interferons and other
substances which modulate the functionality of other cells.
Macrophages cooperate in the immune defense. They
expose molecules of digested bodies on the membrane and
present them to more specialized cells, such as B and T
lymphocytes
Test- No. 1
Enumerate the leucocytes cells and what is the function of
leukocytes cells
6
unit three
1-3 - Platelets (thrombocytes) - help in blood clotting.
The primary function of platelets, or thrombocytes, is blood clotting. Platelets
are much smaller in size than the other blood cells. The normal platelet count
is 150,000-350,000 per microliter of blood They group together to form clumps,
or a plug, in the hole of a vessel to stop bleeding.
2-3 Blood Clotting
When blood vessels are cut or damaged, the loss of blood from the system
must be stopped before shock and possible death occur. This is accomplished
by solidification of the blood, a process called coagulation or clotting.
A blood clot consists of


a plug of platelets enmeshed in a
network of insoluble fibrin molecules.
Platelet aggregation and fibrin formation both require the proteolytic enzyme
thrombin. Clotting also requires:


calcium ions (Ca2+)(which is why blood banks use a chelating agent to
bind the calcium in donated blood so the blood will not clot in the bag).
about a dozen other protein clotting factors. Most of these circulate in
the blood as inactive precursors. They are activated by proteolytic
cleavage becoming, in turn, active proteases for other factors in the
system.
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3-3 Initiating the Clotting Process





Damaged cells display a surface protein called tissue factor (TF)
Tissue factor binds to activated Factor 7.
The TF-7 heterodimer is a protease with two substrates:
o Factor 10 and
o Factor 9
o Let's follow Factor 10 first.
Factor 10 binds and activates Factor 5. This heterodimer is called
prothrombinase because it is a protease that converts prothrombin
(also known as Factor II) to thrombin.
Thrombin has several different activities. Two of them are:
o proteolytic cleavage of fibrinogen (aka "Factor I") to form:
 soluble molecules of fibrin and a collection of small
 fibrinopeptides
o activation of Factor 13 which forms covalent bonds between the
soluble fibrin molecules converting them into an insoluble
meshwork — the clot.
(Thrombin and activated Factors 10 ("Xa") and 11 ("XIa") are serine proteases)
8
4-3 Amplifying the Clotting Process
The clotting process also has several positive feedback loops which quickly
magnify a tiny initial event into what may well be a lifesaving plug to stop
bleeding.



The TF-7 complex (which started the process) also activates Factor 9.
o Factor 9 binds to Factor 8, a protein that circulates in the blood
stabilized by another protein, von Willebrand Factor (vWF).
o This complex activates more Factor 10.
As thrombin is generated, it activates more
o Factor 5
o Factor 8, and
o Factor 11 (all shown above with green arrows).
Factor 11 amplifies the production of activated Factor 9.
Thus what may have begun as a tiny, localized event rapidly expands into a
cascade of activity.
Test No. 1
What is the main functions of platelets
Test No.2
Describe the three basic steps involved in the clotting process
9
Unit four
1-4 Anticoagulants
An anticoagulant is a drug that helps prevent the clotting (coagulation) of
blood. These drugs tend to prevent new clots from forming or an existing clot
from enlarging. They don't dissolve a blood clot. Anticoagulants are also given
to certain people at risk for forming blood clots, such as those with artificial
heart valves or who have atrial fibrillation
A common type of stroke is caused by a blood clot blocking blood flow to the
brain. To prevent such clots, anticoagulants are often prescribed for people
with conditions such as atrial fibrillation to prevent a first or recurrent stroke.
Heparin and warfarin, a derivative of coumarin, are some examples of
anticoagulants
2-4 Hemoglobin
Hemoglobin is the protein that carries oxygen from the lungs to the tissues
and carries carbon dioxide from the tissues back to the lungs. In order to
function most efficiently, hemoglobin needs to bind to oxygen tightly in the
oxygen-rich atmosphere of the lungs and be able to release oxygen rapidly in
the relatively oxygen-poor environment of the tissues. It does this in a most
elegant and intricately coordinated way. The story of hemoglobin is the
prototype example of the relationship between structure and function of a
protein molecules
3-4 Hemoglobin Structure
A hemoglobin molecule consists of four polypeptide chains: two alpha
chains, each with 141 amino acids and two beta chains, each with 146
amino acids. The protein portion of each of these chains is called
"globin". The a and b globin chains are very similar in structure. In this
case, a and b refer to the two types of globin. Students often confuse
this with the concept of a helix and b sheet secondary structures. But,
in fact, both the a and b globin chains contain primarily a helix
secondary structure with no b sheets
10
A heme group is a flat ring molecule containing carbon, nitrogen and hydrogen
atoms, with a single Fe2+ ion at the center. Without the iron, the ring is called a
porphyrin. In a heme molecule, the iron is held within the flat plane by four
nitrogen ligands from the porphyrin ring. The iron ion makes a fifth bond to a
histidine side chain from one of the helices that form the heme pocket. This
fifth coordination bond is to histidine 87 in the human  chain and histidine 92
in the human  chain. Both histidine residues are part of the F helix in each
globin chain.
4-4 The Bohr Effect
The ability of hemoglobin to release oxygen, is affected by pH,
CO2 and by the differences in the oxygen-rich environment of the
lungs and the oxygen-poor environment of the tissues. The pH in
the tissues is considerably lower (more acidic) than in the lungs.
Protons are generated from the reaction between carbon dioxide
and water to form bicarbonate:
CO2 + H20 -----------------> HCO3- + H+
This increased acidity serves a twofold purpose. First, protons
lower the affinity of hemoglobin for oxygen, allowing easier
release into the tissues. As all four oxygens are released,
hemoglobin binds to two protons. This helps to maintain
equilibrium towards the right side of the equation. This is known
as the Bohr effect, and is vital in the removal of carbon dioxide
as waste because CO2 is insoluble in the bloodstream. The
bicarbonate ion is much more soluble, and can thereby be
transported back to the lungs after being bound to hemoglobin. If
hemoglobin couldn’t absorb the excess protons, the equilibrium
would shift to the left, and carbon dioxide couldn’t be removed.
In the lungs, this effect works in the reverse direction. In the
presence of the high oxygen concentration in the lungs, the
proton affinity decreases. As protons are shed, the reaction is
driven to the left, and CO2 forms as an insoluble gas to be
expelled from the lungs. The proton poor hemoglobin now has a
greater affinity for oxygen, and the cycle continue
------------------------------------------------------------------------------------------------------Test –No.1
Define hemoglobin and describe the structure of hemoglobin
Test No. 2
Define anticoagulant and give me two example of it
11
Unit five
1-5 Blood Groups
Blood groups are created by molecules present on the surface of red blood cells (and
often on other cells as well).
2-5 The ABO Blood Groups
The ABO blood groups were the first to be discovered (in 1900) and are the most
important in assuring safe blood transfusions.
The table shows the four ABO phenotypes ("blood groups") present in the human
population and the genotypes that give rise to them.
Blood
Group
Antigens
on RBCs
Antibodies in
Serum
Genotypes
A
A
Anti-B
AA or AO
B
B
Anti-A
BB or BO
AB
A and B
Neither
AB
O
Neither
Anti-A and Anti-B
OO
When red blood cells carrying one or both antigens are exposed to the corresponding
antibodies, they agglutinate; that is, clump together. People usually have antibodies
against those red cell antigens that they lack.
The antigens in the ABO system are O-linked glycoproteins with their sugar residues
exposed at the cell surface. The terminal sugar determines whether the antigen is A or
B.
The critical principle to be followed is that transfused blood must not contain red cells
that the recipient's antibodies can clump. Although theoretically it is possible to
transfuse group O blood into any recipient, the antibodies in the donated plasma can
damage the recipient's red cells. Thus, when possible, transfusions should be done
with exactly-matched blood. than "self".
12
3-5 The Rh System
Rh antigens are transmembrane proteins with loops exposed at the surface of red
blood cells. They appear to be used for the transport of carbon dioxide and/or
ammonia across the plasma membrane. They are named for the rhesus monkey in
which they were first discovered.
There are a number of Rh antigens. Red cells that are "Rh positive" express the one
designated D. About 15% of the population have no RhD antigens and thus are "Rh
negative".
The major importance of the Rh system for human health is to avoid the danger of RhD
incompatibility between mother and fetus.
During birth, there is often a leakage of the baby's red blood cells into the mother's
circulation. If the baby is Rh positive (having inherited the trait from its father) and the
mother Rh-negative, these red cells will cause her to develop antibodies against the
RhD antigen. The antibodies, usually of the IgG class, do not cause any problems for
that child, but can cross the placenta and attack the red cells of a subsequent Rh +
fetus. This destroys the red cells producing anemia and jaundice.
The disease, called erythroblastosis fetalis or hemolytic disease of the newborn, may
be so severe as to kill the fetus or even the newborn infant. It is an example of an
antibody-mediated cytotoxicity disorder.
Other examples of antibody-mediated cytotoxicity disorders.
Although certain other red cell antigens (in addition to Rh) sometimes cause problems
for a fetus, an ABO incompatibility does not. Why is an Rh incompatibility so
dangerous when ABO incompatibility is not?
It turns out that most anti-A or anti-B antibodies are of the IgM class and these do not
cross the placenta. In fact, an Rh−/type O mother carrying an Rh+/type A, B, or AB fetus
is resistant to sensitization to the Rh antigen. Presumably her anti-A and anti-B
antibodies destroy any fetal cells that enter her blood before they can elicit anti-Rh
antibodies in her.
This phenomenon has led to an extremely effective preventive measure to avoid Rh
sensitization. Shortly after each birth of an Rh+ baby, the mother is given an injection
of anti-Rh antibodies. The preparation is called Rh immune globulin (RhIG) or Rhogam.
These passively acquired antibodies destroy any fetal cells that got into her circulation
before they can elicit an active immune response in her.
Rh immune globulin came into common use in the United States in 1968, and within a
decade the incidence of Rh hemolytic disease became very
Test No. 1
What are the types of blood groups in human
Test No. 2
What is the Rh factor
13
Unit sex
1-6 Cardiovascular system
The main components of the human cardiovascular system are the heart and
the blood vessels. It includes: the pulmonary circulation, a "loop" through the
lungs where blood is oxygenated; and the systemic circulation, a "loop"
through the rest of the body to provide oxygenated blood. An average adult
contains five to six quarts (roughly 4.7 to 5.7 liters) of blood, which consists of
plasma, red blood cells, white blood cells, and platelets. Also, the digestive
system works with the circulatory system to provide the nutrients the system
needs to keep the heart pumping
2-6 The heart
The heart weighs between 7 and 15 ounces (200 to 425 grams) and is a little larger than
the size of your fist. By the end of a long life, a person's heart may have beat
(expanded and contracted) more than 3.5 billion times. In fact, each day, the average
heart beats 100,000 times, pumping about 2,000 gallons (7,571 liters) of blood.
.
14
Your heart is located between your lungs in the middle of your chest, behind
and slightly to the left of your breastbone (sternum). A double-layered and
slightly to the left of your breastbone (sternum). A double-layered membrane
called the pericardium surrounds your heart like a sac. The outer layer of the
pericardium surrounds the roots of your heart's major blood vessels and is
attached by ligaments to your spinal column, diaphragm, and other parts of
your body. The inner layer of the pericardium is attached to the heart muscle. A
coating of fluid separates the two layers of membrane, letting the heart move
as it beats, yet still be attached to your body.
Your heart has 4 chambers. The upper chambers are called the left and right
atria, and the lower chambers are called the left and right ventricles. A wall of
muscle called the septum separates the left and right atria and the left and
right ventricles. The left ventricle is the largest and strongest chamber in your
heart. The left ventricle's chamber walls are only about a half-inch thick, but
they have enough force to push blood through the aortic valve and into your
body.
3-6 The Heart Valves :Four types of valves regulate blood flow through your heart:

The tricuspid valve regulates blood flow between the right atrium and
right ventricle.

The pulmonary valve controls blood flow from the right ventricle into
the pulmonary arteries, which carry blood to your lungs to pick up
oxygen.

The mitral valve lets oxygen-rich blood from your lungs pass from the
left atrium into the left ventricle.

The aortic valve opens the way for oxygen-rich blood to pass from the
left ventricle into the aorta, your body's largest artery, where it is
delivered to the rest of your body.
4-6 The Conduction System
Electrical impulses from your heart muscle (the myocardium) cause your heart
to contract. This electrical signal begins in the sinoatrial (SA) node, located at
the top of the right atrium. The SA node is sometimes called the heart's
"natural pacemaker." An electrical impulse from this natural pacemaker travels
through the muscle fibers of the atria and ventricles, causing them to contract.
Although the SA node sends electrical impulses at a certain rate, your heart
rate may still change depending on physical demands, stress, or hormonal
factors
Test No.1
Name the valves of the heart and explain the purpose of each valves
15
Unit seven
1-7 Blood vessels
A VEINS ( proprieties of veins )
1- Veins function to return poorly oxygenated blood to the heart.
2- veins tubes collapse when their lumen are not filled with blood.
3- The thick, outer-most layer of a vein is made of collagen, wrapped in
bands of smooth muscle while the interior is lined with epithelial cells
called intima.
4- Most veins have one-way flaps called venous valves that prevent blood
from flowing back and pooling in the lower extremities due to the effects
of gravity.
5- The precise location of veins is much more variable from person to
person than that of arteries.
B-
ARTERIES ( proprieties of arteries )
1- Arteries are blood vessels that carry blood away from the heart (as
opposed to veins, blood vessels carrying blood toward the heart). All
arteries, with the exception of the pulmonary and umbilical arteries, carry
oxygenated blood.
2- The artery is has three layers: A muscular middle which is very elastic
and strong, an outer layer of tissue, and an inner layer of smooth epithelial
cells that allow the blood to flow easily.
3- The muscular wall of the artery actually helps the heart to pump blood.
When your heart beats the artery expands with blood. Because the artery
keeps pace with the heart you can actually measure how many heart beats
per minute you have by counting the contractions of the artery (pulse rate)
4- Arteries also deliver oxygen rich blood to the capillaries where the actual
exchange of carbon dioxide and oxygen happen.
C- Capillaries ( proprieties of capillaries )
1-
Capillaries are very thin, fragile blood vessels that receive oxygen-rich
blood from arteries, exchange oxygen and carbon dioxide and then deliver
the waste-rich blood to the veins.
2- Capillaries are only one epithelial cell thick and blood can only flow
through them in a single file. The red blood cells inside the capillary release
their oxygen, which passes through the wall and into the surrounding
tissue. The tissue releases its waste products, e.g. carbon dioxide, which
pass through the wall and into the red blood cells. The exchange occurs
16
and the waste blood is carried back to the heart and lungs through the
veins.
2-7 THE BLOOD CIRCULATORY SYSTEM
There are three types of blood circulatory system, two of which (systemic
circulation and pulmonary circulation) depend on a pump, the heart, to push
the blood around. The third type of circulation is known as a portal system.
These are specialised channels that connect one capillary bed site to another
but do not depend directly on a central pump. The largest of these in the
human is the hepatic portal system which connects the intestines to the liver.
3-7 The systemic circulation
transfers oxygenated blood from a central pump (the heart) to all of the body tissues
(systemic arterial system) and returns deoxygenated blood with a high carbon dioxide
content from the tissues to the central pump (systemic venous system).
As briefly mentioned above the systemic circulation supplies all the body tissues, and
is where exchange of nutrients and products of metabolism occurs. All the blood for
the systemic circulation leaves the left side of the heart via the aorta.
This large artery then divides into smaller arteries and blood is delivered to all tissues
and organs. These arteries divide into smaller and smaller vessels each with its own
characteristic structure and function. The smallest branches are called arterioles.
The arterioles themselves branch into a number of very small thin vessels, the
capillaries, and it is here that the exchange of gases, nutrients and waste products
occurs.
Exchange occurs by diffusion of substances down concentration and pressure
gradients.
The capillaries then unite to form larger vessels, venules, which in turn unite to form
fewer and larger vessels, known as veins.
The veins from different organs and tissues unite to form two large veins. The inferior
vena cava (from the lower portion of the body) and the superior vena cava (from the
head and arms), which return blood to the right side of the heart. Thus there are a
number of parallel circuits within the systemic circulation.
4-7The pulmonary circulation
is where oxygen and carbon dioxide exchange between the blood and
alveolar air occurs. The blood leaves the right side of the heart through a
single artery, the pulmonary artery, which divides into two - one branch
supplying each lung. Within the lung, the arteries divide, ultimately
forming arterioles and capillaries; venules and veins return blood to the
left side of the heart.
5-7Portal circulation:Normally there is only one capillary bed for each branch of a circuit; however,
there are a few instances where there are two capillary beds, one after each
other, in series. These are known as portal systems or portal circulations. One
17
example of this is in the liver. Part of the blood supply to the liver is venous
blood coming directly from the gastrointestinal tract and spleen via the hepatic
portal vein. This arrangement enables the digested and absorbed substances
from the gut to be transported directly to the liver, where many of the body's
metabolic requirements are synthesised. Thus there are two
micro-circulations in series, one in the gut and the other in the
liver.
The force required to move the blood through the blood vessels in
the two circulations is provided by the heart, which functions as
two pumps, the left side of the heart supplying the systemic
circulation and the right side the pulmonary circulation.
The systemic circulation is much larger than the pulmonary circulation and
thus the force generated by the left side of the heart is much greater than that
of the right side of the heart. However, as the circulatory system is a closed
system, the volume of blood pumped through the pulmonary circulation in a
given period of time must equal the volume pumped through the systemic
circulation - that is, the right and left sides of the heart must pump the same
amount of blood. In a normal resting adult, the average volume of blood
pumped simultaneously is approximately 5 liters per min. As there are
approximately 5 liters of blood in an adult, this means that the blood circulates
around the body approximately once every minute. During heavy work or
exercise, the volume of blood pumped by the heart can increase up to 25 liters
per min .
------------------------------------------------------------------------------
Test No. 1
Enumerate the blood vessels and distinguish between them in
properties
Test No. 2
How many blood circulations in human body Explain one
18
Unit eight
1-8 Heart beat
A heartbeat is a two-part pumping action that takes about a second. As blood
collects in the upper chambers (the right and left atria), the heart's natural
pacemaker (the SA node) sends out an electrical signal that causes the atria to
contract. This contraction pushes blood through the tricuspid and mitral
valves into the resting lower chambers (the right and left ventricles). This part
of the two-part pumping phase (the longer of the two) is called diastole.
The second part of the pumping phase begins when the ventricles are full of
blood. The electrical signals from the SA node travel along a pathway of cells
to the ventricles, causing them to contract. This is called systole. As the
tricuspid and mitral valves shut tight to prevent a back flow of blood, the
pulmonary and aortic valves are pushed open. While blood is pushed from the
right ventricle into the lungs to pick up oxygen, oxygen-rich blood flows from
the left ventricle to the heart and other parts of the body.
After blood moves into the pulmonary artery and the aorta, the ventricles relax,
and the pulmonary and aortic valves close. The lower pressure in the
ventricles causes the tricuspid and mitral valves to open, and the cycle begins
again. This series of contractions is repeated over and over again, increasing
during times of exertion and decreasing while you are at rest. The heart
normally beats about 60 to 80 times a minute when you are at rest, but this can
vary. As you get older, your resting heart rate rises. Also, it is usually lower
in people who are physically fit.
19
2-8 blood pressure
Blood pressure is the pressure of the blood against the walls of the arteries.
Blood pressure results from two forces. One is created by the heart as it
pumps blood into the arteries and through the circulatory system. The other is
the force of the arteries as they resist the blood flow.
What do blood pressure numbers indicate?


The higher (systolic) number represents the pressure while the heart
contracts to pump blood to the body.
The lower (diastolic) number represents the pressure when the heart
relaxes between beats.
Blood pressure changes during the day. It is lowest as you sleep and rises
when you get up. It also can rise when you are excited, nervous, or active.
Still, for most of your waking hours, your blood pressure stays pretty much the
same when you are sitting or standing still. That level should be lower than
120/80. When the level stays high, 140/90 or higher, you have high blood
pressure. With high blood pressure, the heart works harder, your arteries take
a beating, and your chances of a stroke, heart attack, and kidney problems are
greater.
What causes it?
In many people with high blood pressure, a single specific cause is not known.
This is called essential or primary high blood pressure. Research is continuing
to find causes.
In some people, high blood pressure is the result of another medical problem
or medication. When the cause is known, this is called secondary high blood
pressure.
What is high blood pressure?
A blood pressure of 140/90 or higher is considered high blood pressure. Both
numbers are important. If one or both numbers are usually high, you have high
blood pressure. If you are being treated for high blood pressure, you still have
high blood pressure even if you have repeated readings in the normal range.
20
3-8 Factors Affect Blood Pressure Readings?
There a number of factors that will temporarily affect blood pressure.
Most are short-lived and will affect your blood pressure
temporarily and then blood pressure will return to resting blood
pressure.
Short-lived factors that may cause changes in blood pressure,
both raising and lowering, include:










Asleep or awake – usually lower when sleeping
Body position - lying down, sitting or standing
Emotional state - such as stress and anger or being relaxed
Activity level - from not moving to extreme exertion
Temperature – blood pressure will tend to go up when you are cold
White coat hypertension – blood pressure increases in a medical setting
Sleep apnea - pauses in breathing while sleeping raise blood pressure
Smoking – increases blood pressure
Caffeine – increases blood pressure
Alcohol – increases blood pressure
Of the above list, sleep apnea, smoking, alcoholism and chronic stress
are the major factors that can, over extended periods of time,
cause resting blood pressure to slowly increase due to the impact
they have on the body.
There are two levels of high blood pressure: Stage 1 and Stage 2 (see the chart
below).
Categories for Blood Pressure Levels in Adults*
(In mmHg, millimeters of mercury)
Category
Systolic
(Top number)
Diastolic
(Bottom number)
Normal
Less than 120
Less than 80
Prehypertension
120-139
80-89
High Blood Pressure
Systolic
Diastolic
Stage 1
140-159
90-99
Stage 2
160 or higher
100 or higher
21
* For adults 18 and older who:

Are not on medicine for high blood pressure

Are not having a short-term serious illness

Do not have other conditions such as diabetes and kidney disease
Note: When systolic and diastolic blood pressures fall into different
categories, the higher category should be used to classify blood pressure
level. For example, 160/80 would be stage 2 high blood pressure.
There is an exception to the above definition of high blood pressure. A
blood pressure of 130/80 or higher is considered high blood pressure in
persons with diabetes and chronic kidney disease
--------------------------------------------------------------------------------------------------
Test No. 1
Define blood pressure and what is the normal rate of blood pressure
Test No. 2
Enumerate the factor that effecting on blood pressure reading
22
Unit nine
Respiratory system
The primary function of the respiratory system is the supply of oxygen to the blood so
this in turn delivers oxygen to all parts of the body. The respiratory system does this
while breathing is taking place. During the process of breathing we inhale oxygen and
exhale carbon dioxide. This exchange of gases takes place at the alveoli. The average
adult's lungs contain about 600 million of these spongy, air-filled sacs that are
surrounded by capillaries. The inhaled oxygen passes into the alveoli and then
diffuses through the capillaries into the arterial blood. Meanwhile, the waste-rich blood
from the veins releases its carbon dioxide into the alveoli. The carbon dioxide follows
the same path out of the lungs when you exhale.
1-9 the principle functions of the respiratory system are:

Ventilate the lungs

Extract oxygen from the air and transfer it to the bloodstream

Excrete carbon dioxide and water vapour

Maintain the acid base of the blood
inspired Air
This contains approx:

79% nitrogen

20% O2

0.04% CO2

Water vapour/Trace Gases
Expired Air
This contains approx:

79% nitrogen

16% O2

4% CO2

Water vapour/Trace Gases
23
2-9 Structure of the respiratory System
Respiration takes place with the aid of the mouth, nose, trachea, lungs,
diaphragm and intercostal muscles . Oxygen enters the respiratory system
through the mouth and the nose. The oxygen then passes through the larynx
and the trachea. In the chest cavity, the trachea splits into two bronchi. Each
bronchus then divides again forming the bronchial tubes. The bronchial tubes
lead directly into the lungs where they divide into many smaller tubes which
connect to tiny sacs called alveoli.
1- The lungs
Structure
The lungs are paired, cone-shaped organs which take up most of the space in
our chests, along with the heart. Their role is to take oxygen into the body,
which we need for our cells to live and function properly, and to help us get rid
of carbon dioxide, which is a waste product. We each have two lungs, a left
lung and a right lung. These are divided up into 'lobes', or big sections of
tissue separated by 'fissures' or dividers. The right lung has three lobes but
the left lung has only two, because the heart takes up some of the space in the
left side of our chest. The lungs can also be divided up into even smaller
portions, called 'bronchopulmonary segments'.
These are pyramidal-shaped areas which are also separated from each other
by membranes. There are about 10 of them in each lung. Each segment
receives its own blood supply and air supply.
3-9 How they work
Air enters your lungs through a system of pipes called the bronchi. These
pipes start from the bottom of the trachea as the left and right bronchi and
branch many times throughout the lungs, until they eventually form little thinwalled air sacs or bubbles, known as the alveoli. The alveoli are where the
important work of gas exchange takes place between the air and your blood.
Covering each alveolus is a whole network of little blood vessel called
capillaries, which are very small branches of the pulmonary arteries. It is
24
important that the air in the alveoli and the blood in the capillaries are very
close together, so that oxygen and carbon dioxide can move (or diffuse)
between them. So, when you breathe in, air comes down the trachea and
through the bronchi into the alveoli. This fresh air has lots of oxygen in it, and
some of this oxygen will travel across the walls of the alveoli into your
bloodstream. Travelling in the opposite direction is carbon dioxide, which
crosses from the blood in the capillaries into the air in the alveoli and is then
breathed out. In this way, you bring in to your body the oxygen that you need
to live, and get rid of the waste product carbon dioxide.
4-9 Blood Supply
The lungs are very vascular organs, meaning they receive a very large blood
supply. This is because the pulmonary arteries, which supply the lungs, come
directly from the right side of your heart. They carry blood which is low in
oxygen and high in carbon dioxide into your lungs so that the carbon dioxide
25
can be blown off, and more oxygen can be absorbed into the bloodstream. The
newly oxygen-rich blood then travels back through the paired pulmonary veins
into the left side of your heart. From there, it is pumped all around your body to
supply oxygen to cells and organs.
5-9 Functions of the lungs
In addition to their function in respiration, the lungs also:








alter the pH of blood by facilitating alterations in the partial pressure of
carbon dioxide
filter out small blood clots formed in veins
filter out gas micro-bubbles occurring in the venous blood stream such
as those created after scuba diving during decompression. influence
the concentration of some biologic substances and drugs used in
medicine in blood
convert angiotensin I to angiotensin II by the action of angiotensinconverting enzyme
may serve as a layer of soft, shock-absorbent protection for the heart,
which the lungs flank and nearly enclose.
Media: Immunoglobulin-A is secreted in the bronchial secretion and
protects against respiratory infections.
maintain sterility by producing mucus containing antimicrobial
compounds.] Mucus contains glycoproteins, eg mucins, lactoferrin
lysozyme, lactoperoxidase. We find also on the epithelium Dual oxidase
proteins generating hydrogen peroxidde, useful for hypothiocyanite
endogenous antimicrobial synthesis. Function not in place in cystic
fibrosis patient lungs.
Ciliary escalator action is an important defence system against airborne infection. The dust particles and bacteria in the inhaled air are
caught in the mucous layer present at the mucosal surface of
respiratory passages and are moved up towards pharynx by the
rhythmic upward beating action of the cilia
--------------------------------------------------------------------------------------------------Test No. 1
Enumerate the functions of the lungs
Test No. 2
Comber between inspiration and expiration process
Test No. 3
List the respiratory volume
Note :- this test involved unit( 9,10& 11 )
26
Unit ten
1-10 conducting air ways
1-
Nose: • Olfaction (smelling)
• Assists in producing sound
• Warming and Humidifying. Highly vascularized mucus membrane that warms
and humidifies inspired air. Without this function the trachea can become dry.
• Upper one-third of the nasal cavity is lined with olfactory epithelium the lower
two-thirds are lined with pseudostratified ciliated columnar epithelium.
• All the way through the respiratory tract there are numerous mucous
secreting goblet cells with microvilli on the surface.
• Cilia plays an important role in propelling mucous and trapped particles in to
the pharynx where it is swallowed or spat out.
2- Pharynx:
• Extends from the base of the skull to the inferior border of the cricoids
cartilage
• Continuous interiorly with the trachea and posterior with the esophagus
• Divided into 3 parts; Nasopharynx, Or pharynx, Laryngopharynx.
• Oro and Laryngopharynx are part of the respiratory and alimentary tract and
are lined with non-keratinized stratified squamous (NKSS)
3- Larynx:
• Inferior end continuous with the trachea. Superior end attached to the hyoid
bone and lies below the epiglottis
• Protects the trachea from foreign objects and particles.
• Assists in warming and humidifying incoming air
• Made of cartilaginous material
• The larynx is lined with NKSS epithelium as well as pseudostratified ciliated
columnar epithelium
• Includes; Epiglottis, Thyroid, Arytenoids and Cricoids cartilages
• Vocal cords are housed in this area. Air rushing past these cords cause them
to vibrate thus making sound
27
4- Trachea:
• 10cm in length, 2.5cm in diameter and constructed of incomplete C-shaped
hyaline cartilage. Rings are completed posteriorly by the trachealis muscle
• Extends from the larynx to the carina; level with 4th and 5th thoracic vertebra
5- Bronchi:
• Primary bronchi is inferior to the carina; bifurcation of the trachea.
• The bronchi are similar in structure to that of the trachea and are lined with
ciliated columnar epithelium. As the tubes become smaller the cartilages
become irregular and also become smaller until the tubes get to 1mm, this is
when the cartilage disappears. As there is no cartilage the smooth muscle
becomes thicker.
6- Bronchioles:
• No cartilage as the smooth muscle is thicker to help maintain the structure.
• The smooth muscle is responsive to autonomic nerve stimulation
• The internal walls are lined with ciliated columnar mucous membrane but as
the walls extend towards the distal bronchiole this membranous layer changes
to non-ciliated cuboidal-shaped cells.
7- Terminal Bronchioles:
• Split into 2 or more respiratory bronchioles
• Thinner walls and are lined with ciliated columnar epithelium.
• Do not contain any goblet cells.
• Increased numbers of clara cells that line the lumen and secrete an agent
similar to surfactant
28
29
Unit eleven
1-11 breathing
Air from the atmosphere passes through the conducting airway until it reaches
the alveoli. The walls of the alveoli are only one cell thick and this is called the
respiratory surface, which is about 70 square meters, where the exchange of
gases takes place. Around the alveoli are microscopic capillaries that bring
carbon dioxide from the heart via pulmonary artery and delivers oxygen back
to the heart via the pulmonary vein. Gas exchange happens when there is a
difference in partial pressure at the semi-permeable membrane of the alveoli
(diffusion). The diffusion occurs when the higher concentration of a gas moves
to the lower concentration until equilibrium is achieved
Partial Pressure of Gases
Deoxygenated Blood
Gas
Alveolar
Oxygenated Blood
O2
105 mmHg
40 mmHg
100 mmHg
CO2
40 mmHg
44 mmHg
40 mmHg
Using the table above, we can see that oxygenated blood from the alveolar will
diffuse across the semi-permeable membrane and replace the lower
concentration of 02 in the deoxygenated blood. The higher concentration of
C02 will diffuse in the same way. This is because Dalton’s law states ‘each gas
exerts its own pressure in proportion to it’s concentration in a mixture’. Inhaled
02 has a higher percentage than exhaled 02, its pressure is higher at 100mmHg
compared to the 40mmHg of lower percentage from the deoxygenated blood.
The reverse of this applies to the C02 because the percentage breathed in is
lower than that which is exhaled.
2-11

inspiration and expiration process
Inspiration- Diaphragm and intercostals muscles contract. The
diaphragm moves downwards. The intercostals muscles make the rib
cage move upwards. These two processes increase the volume of the
thoracic cavity and also reduces the air pressure to below atmospheric
pressure allowing air to rush into the airways then into the alveoli.
30

Expiration is the opposite of inspiration as in the diaphragm and
intercostals muscles relax, this allows the diaphragm to move upwards
and the intercostals muscles let the rib cage relax to its resting state.
The volume within the thoracic cavity now decreases. This decrease in
volume now causes an increase in pressure above atmospheric
pressure which forces air out up the airway .
3-11 Central Control
Breathing is clearly an involuntary process (you don't have to think about it),
and like many involuntary processes (such as heart rate) it is controlled by a
region of the brain called the medulla. The medulla and its nerves are part of
the autonomic nervous system (i.e. involuntary). The region of the medulla that
controls breathing is called the respiratory centre. The main centers are the
apneustic centre, which enhances inspiration, and the pneumotaxic centre,
which terminates inspiration.
The respiratory centre transmits regular nerve impulses to the diaphragm and
intercostal muscles to cause inhalation. Stretch receptors in the alveoli and
bronchioles detect inhalation and send inhibitory signals to the respiratory
centre to cause exhalation. This negative feedback system in continuous and
prevents damage to the lungs
Ventilation is also under voluntary control from the cortex, the voluntary part
of the brain. This allows you to hold your breath or blow out candles, but it can
be overruled by the autonomic system in the event of danger. For example if
31
you hold your breath for a long time, the carbon dioxide concentration in the
blood increases so much that the respiratory centre forces you to gasp and
take a breath.
Peripheral Chemoreceptor
A chemoreceptor, is a cell or group of cells that transducer a chemical signal
into an action potential
Chemo receptors in the carotid arteries and aorta, detect the levels of carbon
dioxide in the blood. To do this, they monitor the concentration of hydrogen
ions in the blood, which increases the pH of the blood, as a direct
consequence of the raised carbon dioxide concentration.
The response is that the inspiratory control from the apneustic centre, sends
nervous impulses to the external intercostals muscles and the diaphragm, via
the phrenic nerve to increase breathing rate and the volume of the lungs
during inhalation.
4-11 Respiratory volume

Total lung capacity (TC), about six liters, is all the air the lungs can hold.

Vital capacity (VC) The maximum volume of air that can be expelled at
the normal rate of exhalation after a maximum inspiration

Tidal volume (TV) is the amount of air breathed in or out during normal
respiration. It is normally from 450 to 500 mL.

Residual volume (RV) is the amount of air left in the lungs after a
maximal exhalation. This averages about 1.5 L.

Expiratory reserve volume (ERV) is the amount of additional air that can
be breathed out after normal expiration. This is about 1.5 L.

Inspiratory reserve volume similarly, is the additional air that can be
inhaled after a normal tidal breath in. About 2.5 more liters can be
inhaled.

Functional residual capacity, (ERV + RV), is the amount of air left in the
lungs after a tidal breath out.

Inspiratory capacity (IC) is the volume that can be inhaled after a tidal
breath out.

Anatomical dead space is the volume of the airways.
32
Unit twelve
Renal system
1-12 structure of renal system
The renal system consists of all the organs involved in the formation and
release of urine. It includes the kidneys, ureters, bladder and urethra.
1- The kidneys
are bean-shaped organs which help the body produce urine to get rid of
unwanted waste substances. When urine is formed, tubes called ureters
transport it to the urinary bladder, where it is stored and excreted via the
urethra.
2- Bladder
The bladder is a pyramid-shaped organ which sits in the pelvis (the bony
structure which helps form the hips). The main function of the bladder is to
store urine and, under the appropriate signals, release it into a tube which
carries the urine out of the body. Normally, the bladder can hold up to 500 mL
of urine. The bladder has three openings: two for the ureters and one for the
urethra (tube carrying urine out of the body). The bladder consists of smooth
muscles. The main muscle of the bladder is called the detrusor muscle. Muscle
fibres around the opening of the urethra forms a ring-like muscle that controls
the passage of urine. When we want to urinate, stretch receptors in the bladder
are activated, which send signals to our brain and tell us that the bladder is
full. The ring-like muscle relaxes and the detrusor muscle contracts, allowing
urine to flow. The blood supply of the bladder is from many blood vessels.
Some of these blood vessels are named: the vesical arteries, the obturator,
uterine, gluteal and vaginal arteries. In females, a venous network drains blood
from the bladder arteries into the internal iliac vein. Nervous control of the
bladder involves centres located in the brain and spinal cord
33
3- Urethra
The male urethra is 18–20 cm long, running from the bladder to the tip of the
penis. The male urethra is supplied by the inferior vesical and middle rectal
arteries. The veins follow these blood vessels. The nerve supply is via the
pudendal nerve.
The female urethra is 4–6 cm long and 6 mm wide. It is a tube running from the
bladder neck and opening into an external hole located at the top of the vaginal
opening. As the female urethra is shorter than the male urethra, it is more likely
to get infections from bacteria in the vagina. The female urethra is supplied by
the internal pudendal and vaginal arteries.
34
2-12 structure of kidney
On sectioning, the kidney has a pale outer region- the cortex- and
a darker inner region- the medulla.The medulla is divided into 818 conical regions, called the renal pyramids; the base of each
pyramid starts at the corticomedullary border, and the apex ends
in the renal papilla which merges to form the renal pelvis and then
on to form the ureter. In humans, the renal pelvis is divided into
two or three spaces -the major calyces- which in turn divide into
further minor calyces. The walls of the calyces, pelvis and ureters
are lined with smooth muscle that can contract to force urine
towards the bladder by peristalisis.
The cortex and the medulla are made up of nephrons; these are
the functional units of the kidney, and each kidney contains about
1.3 million of them.
35
3-12 structure of nephron
The nephron is the unit of the kidney responsible for ultrafiltration of the blood
and reabsorption or excretion of products in the subsequent filtrate. Each
nephron is made up of:




A filtering unit- the glomerulus. 125ml/min of filtrate is formed by the
kidneys as blood is filtered through this sieve-like structure. This
filtration is uncontrolled.
The proximal convoluted tubule. Controlled absorption of glucose,
sodium, and other solutes goes on in this region.
The loop of Henle. This region is responsible for concentration and
dilution of urine by utilising a counter-current multiplying mechanismbasically, it is water-impermeable but can pump sodium out, which in
turn affects the osmolarity of the surrounding tissues and will affect the
subsequent movement of water in or out of the water-permeable
collecting duct.
The distal convoluted tubule. This region is responsible, along with the
collecting duct that it joins, for absorbing water back into the bodysimple maths will tell you that the kidney doesn't produce 125ml of urine
every minute. 99% of the water is normally reabsorbed, leaving highly
concentrated urine to flow into the collecting duct and then into the
renal pelvis.
Test No.1
Describe the structure of nepheron
Test no.2
Enumerate the functions of kidney ( this test for unit 13 )
36
Unit thirteen
1-13 functions of the kidney
1. Control of the body's water balance. The amount of water in the body must
be balanced against the amount of water which we drink and the amount we
lose in urine and sweat etc.
2. Regulation of blood pressure via the renin-angiotensin-aldosterone system
3. Regulation of blood electrolyte balance - Na+, Ca2+, K+ etc.
4. Excretion of metabolic wastes such as urea, creatinine and foreign
substances such as drugs and the chemicals we ingest with our food
5. Help in the regulation of the body’s acid base balance
6. Regulation of red blood cell production via the hormone erythropoietin
7. Help in the production of vitamin D
As this list indicates, the renal system is very important to the normal
functioning of the body.
2-13 water regulations by the kidneys
The water content of the body can vary depending on various factors. Hot
weather and physical activity such as exercise make us sweat and so lose
body fluids. Drinking tends to be at irregular intervals when socially
convenient. This means that sometimes the body has too little water and needs
to conserve it and sometimes too much water and needs to get rid of it. Most of
the control of water conservation takes place in the distal and collecting
tubules of the nephrons under control of anti-diuretic hormone, (ADH),
sometimes called vasopressin. This hormone is released by the posterior
pituitary under control of the hypothalamus in the mid-brain area. The
hypothalamus monitors the water content of the blood. If the blood contains
too little water (indicating dehydration) then more ADH is released. If the blood
contains too much water (indicating over-hydration) then less ADH is released
into the blood stream
37
Release of ADH from the posterior pituitary into the bloodstream
ADH released from the pituitary travels in the blood stream to the peritubular
capillaries of the nephron. ADH binds to receptors on the distal and collecting
tubules of the nephrons which causes water channels to open in the tubule
walls. This allows water to diffuse through the tubule walls into the interstitial
fluid where it is collected by the peritubular capillaries. The more ADH present,
the more water channels are open and the more water is reabsorbed - Figure
Reabsorption of water from the filtrate under the influence of ADH
Over 99% of the filtrate produced each day can be reabsorbed. The amount of
water reabsorbed from the filtrate back into the blood depends on the water
situation in the body. When the body is dehydrated, most of the filtrate is
reabsorbed but note that even in cases of extreme of water shortage, the
kidneys will continue to produce around 500 ml of urine each day in order to
perform their excretory function.
38
Unit fourteen
1-14 The formation of urine
Filtration ,reaborption ,and secretion.
1- Filtration
Urine formation begins with the process of filtration, which goes on continually
in the renal corpuscles.As blood courses through the glomeruli, much of its
fluid, containing both useful chemicals and dissolved waste materials, soaks
out of the blood through the membranes (by osmosis and diffusion) where it is
filtered and then flows into the Bowman's capsule. This process is called
glomerular filtration. The water, waste products, salt, glucose, and other
chemicals that have been filtered out of the blood are known collectively as
glomerular filtrate. The glomerular filtrate consists primarily of water, excess
salts (primarily Na+ and K+), glucose, and a waste product of the body called
urea. Urea is formed in the body to eliminate the very toxic ammonia products
that are formed in the liver from amino acids. Since humans cannot excrete
ammonia, it is converted to the less dangerous urea and then filtered out of the
blood. Urea is the most abundant of the waste products that must be excreted
by the kidneys. The total rate of glomerular filtration (glomerular filtration rate
or GFR) for the whole body (i.e., for all of the nephrons in both kidneys) is
normally about 125 ml per minute. That is, about 125 ml of water and dissolved
substances are filtered out of the blood per minute.
2- Reabsorption
Reabsorption, by definition, is the movement of substances out of the renal
tubules back into the blood capillaries located around the tubules (called the
peritubular copillaries). Substances reabsorbed are water, glucose and other
nutrients, and sodium (Na+) and other ions. Reabsorption begins in the
proximal convoluted tubules and continues in the loop of Henle, distal
convoluted tubules, and collecting tubules (Figure 3). Let's discuss for a
moment the three main substances that are reabsorbed back into the
bloodstream.
Large amounts of water - more than 178 liters per day - are reabsorbed back
into the bloodstream from the proximal tubules because the physical forces
acting on the water in these tubules actually push most of the water back into
the blood capillaries. In other words, about 99% of the 180 liters of water that
leave the blood each day by glomerular filtration returns to the blood from the
proximal tubule through the process of passive reabsorption.
The nutrient glucose (blood sugar) is entirely reabsorbed back into the blood
from the proximal tubules. In fact, it is actively transported out of the tubules
and into the peritubular capillary blood. None of this valuable nutrient is
wasted by being lost in the urine. However, even when the kidneys are
operating at peak efficiency, the nephrons can reabsorb only so much sugar
and water. Their limitations are dramatically illustrated in cases of diabetes
mellitus, a disease which causes the amount of sugar in the blood to rise far
39
above normal. As already mentioned, in ordinary cases all the glucose that
seeps out through the glomeruli into the tubules is reabsorbed into the blood.
But if too much is present, the tubules reach the limit of their ability to pass the
sugar back into the bloodstream, and the tubules retain some of it. It is then
carried along in the urine, often providing a doctor with her first clue that a
patient has diabetes mellitus. The value of urine as a diagnostic aid has been
known to the world of medicine since as far back as the time of Hippocrates.
Since then, examination of the urine has become a regular procedure for
physicians as well as scientists.
Sodium ions (Na+) and other ions are only partially reabsorbed from the renal
tubules back into the blood. For the most part, however, sodium ions are
actively transported back into blood from the tubular fluid. The amount of
sodium reabsorbed varies from time to time; it depends largely on how much
salt we take in from the foods that we eat. (As stated earlier, sodium is a major
component of table salt, known chemically as sodium chloride.) As a person
increases the amount of salt taken into the body, that person's kidneys
decrease the amount of sodium reabsorption back into the blood. That is, more
sodium is retained in the tubules. Therefore, the amount of salt excreted in the
urine increases. The process works the other way as well. The less the salt
intake, the greater the amount of sodium reabsorbed back into the blood, and
the amount of salt excreted in the urine decreases.
3- secreation
Now, let's describe the third important process in the formation of urine.
Secretion is the process by which substances move into the distal and
collecting tubules from blood in the capillaries around these tubules. In this
respect, secretion is reabsorption in reverse. Whereas reabsorption moves
substances out of the tubules and into the blood, secretion moves substances
out of the blood and into the tubules where they mix with the water and other
wastes and are converted into urine. These substances are secreted through
either an active transport mechanism or as a result of diffusion across the
membrane. Substances secreted are hydrogen ions (H+), potassium ions (K+),
ammonia (NH3), and certain drugs. Kidney tubule secretion plays a crucial role
in maintaining the body's acid-base balance, another example of an important
body function that the kidney participates in.
Summary
In summary, three processes occurring in successive portions of the nephron
accomplish the function of urine formation:
1. Filtration of water and dissolved substances out of the blood in the
glomeruli and into Bowman's capsule;
2. Reabsorption of water and dissolved substances out of the kidney
tubules back into the blood (note that this process prevents substances
needed by the body from being lost in the urine);
3. Secretion of hydrogen ions (H+), potassium ions (K+), ammonia (NH3),
and certain drugs out of the blood and into the kidney tubules, where
they are eventually eliminated in the urine.
40
2-14 the urine
is the fluid excreted by the kidneys. It consists of water, carrying in solution
the body's waste products such as urea, uric acid, creatinine, organic acids,
and also other solutes such as Na+, K+, Ca2+, Mg2+, Cl-, the body fluid
concentrations of which are regulated by the kidneys.
After being produced by the kidneys, urine passes along the ureters to be
stored in the bladder, until it is allowed to flow out of the body through the
urethra, in the process of micturition (urination). The smooth muscle of the
bladder forms an internal sphincter at its junction with the urethra, and further
along the urethra is the voluntary-control external sphincter. The bladder
begins to contract (micturition reflex), and produces the desire to urinate,
when its volume exceeds about 200 ml. However, if we do not relax the external
sphincter, the contractions subside, but return with increasing force and
frequency as the bladder continues to fill. When the bladder volume is about
500 ml the micturition reflex may force open the internal sphincter and lead to
a reflex relaxation of the external sphincter, so that urination occurs
involuntarily.
Voluntary urination involves relaxation of the external sphincter and tensing of
the abdominal muscles to increase abdominal pressure and compress the
bladder, to initiate bladder contraction and relaxation of the internal sphincter.
Most people excrete about 1.5 litres of urine per day, but the volume can range
(in healthy adults) from 400 ml up to about 25 litres, depending on fluid intake.
In renal failure, there may be no urine production, and in the rare condition of
untreated diabetes insipidus, the urine volume is consistently 25 litres/day.
Urine is termed ‘dilute’ if its solute concentration (osmolality) is lower than that
of the blood plasma, and ‘concentrated’ if its solute concentration is greater
than that of the plasma.
Humans who are maximally conserving water — when their kidneys are
reabsorbing as much as possible — can produce urine with a solute
concentration (osmolality) about five times that of blood plasma. Many other
animals can conserve water much more effectively. For example, cats, dogs,
and rats can produce urine of ten times the plasma osmolality, and gerbils
twenty times!
41
When voided, urine is normally sterile and clear, although it has a yellow
colour due to the presence of pigments. However, small amounts of particulate
matter such as epithelial cells and lipids may be present; these are ‘casts’.
Protein is not normally filtered from the blood plasma by the kidneys, so
protein in the urine — proteinuria — is generally indicative of damage to the
glomeruli, at the blind inner ends of the kidney tubules, where filtration occurs.
The urine may also appear to contain blood (haematuria). This may be due to
haemolysis in the bloodstream (breakdown of red cells) so that some
haemoglobin is released from them and excreted, or it may be due to the
presence of whole red cells, as a result of bleeding in the kidneys or urinary
tract.
Test No. 1
What is urine ? where and how it formed
Test No. 2
What is micturition ? how is it controlled ?
42
Unit fifteen
1-15 Kidney Stones
In some people, chemicals crystallize in the urine and form the beginning, of a
kidney stone. These stones are very tiny when they form, smaller than a grain
of sand, but gradually can grow over time to a 1/10 of an inch or larger.
Urolithiasis is the term that refers to the presence of stones in the urinary tract,
while nephrolithiasis refers to kidney stones. The size of the stone doesn't
matter as much as where it is located.
When the stone sits in the kidney, it rarely causes problems, but when it falls
into the ureter, it acts like a dam. As the kidney continues to function and make
urine, pressure builds up behind the stone and causes the kidney to swell. This
pressure is what causes the pain of a kidney stone, but it also helps push the
stone along the course of the ureter. When the stone enters the bladder, the
obstruction in the ureter is relieved and the symptoms of a kidney stone are
resolved.
2-15 kidney stones causes
1- Heredity: Some people are more susceptible to forming kidney
stones, and heredity may play a role. The majority of kidney stones are
made of calcium, and hypercalciuria (high levels of calcium in the urine) is a
risk factor. The predisposition to high levels of calcium in the urine may be
passed on from generation to generation. Some rare hereditary diseases
also predispose some people to form kidney stones. Examples include
people with renal tubular acidosis and people with problems metabolizing a
variety of chemicals including cystine (an amino acid), oxalate, (a type of
salt), and uric acid (as in gout).
2- Geographical location: There may be a geographic predisposition to
form kidney stones. There are regional "stone belts," with people living in
the southern United States, having an increased risk of stone formation. The
hot climate and poor fluid intake may cause people to be relatively
dehydrated, with their urine becoming more concentrated and allowing
chemicals to come in closer contact to form the nidus, or beginning, of a
stone.
3- Diet: Diet may or may not be an issue. If a person is susceptible to
forming stones, then foods high in calcium may increase the risk;
however, if a person isn't susceptible to forming stones, diet will not
change that risk.
4- Medications: People taking diuretics (or "water pills") and those who
consume excess calcium-containing antacids can increase the amount of
43
calcium in their urine and potentially increase their risk of forming stones.
Taking excess amounts of vitamins A and D are also associated with
higher levels of calcium in the urine. Patients with HIV who take the
medication indinavir (Crixivan) can form indinavir stones. Other commonly
prescribed medications associated with stone formation include dilantin
and antibiotics like ceftriaxone (Rocephin) and ciprofloxacin (Cipro).
5- Underlying illnesses: Some chronic illnesses are associated with
kidney stone formation, including cystic fibrosis, renal tubular acidosis, and
inflammatory bowel disease.
Test no. 1
Enumerate the causes of Kidney stones
44
Unit sixteen
The kidney effects on blood pressure
1-16 RENIN-ANGIOTENSIN-ALDOSTERONE SYSTEM
The long-term control of blood pressure is via the renin-angiotensinaldosterone (RAA) system. This system is also one of the body's
compensatory mechanisms to a fall in blood pressure. The kidneys release
renin into the bloodstream and this converts angiotensinogen to angiotensin I
which in turn is converted to angiotensin II by angiotensin converting enzyme
in the capillaries of the lungs. Under the influence of Angiotensin II,
aldosterone levels increase. This increases blood sodium levels by decreasing
the amount of salt excreted by the kidneys. Retaining salt instead of excreting
it into urine increases the osmolarity of the blood and so the blood volume. As
the volume increases, so does the blood pressure. Angiotensin II is also a
potent vasoconstrictor which raises blood pressure by increasing vascular
resistance -.
The Renin, angiotensin, aldosterone response to a fall in blood pressure
45
2-16 acid base balance
The body controls the acidity of the blood very carefully because any deviation
from the normal pH of around 7.4 can cause problems - especially with the
nervous system. Deviations in pH can occur due to trauma or diseases such as
diabetes, pneumonia and acute asthma. The mechanisms that resist and
redress pH change are...
1. Minor changes in pH are resisted by plasma proteins acting as buffers in the
blood.
2. Adjustment to the rate and depth of breathing. An increase in acidity
(decrease in pH) increases the rate and depth of breathing which gets rid of
carbon dioxide from the blood and so reduces acidity.
3. The kidneys respond to changes in blood pH by altering the excretion of
acidic or basic ions in the urine. If the body becomes more acidic, the kidneys
excrete acidic hydrogen ions (H+) and conserve basic bicarbonate ions
(HCO3). If the body becomes more basic, the kidneys excrete basic
bicarbonate ions and conserve acidic hydrogen ions.
Together, these three mechanisms maintain tight control over the pH of the
body.
46
Unit seventeen
Digestive system
The Structure and Function of the Digestive System
The digestive system is a series of hollow organs joined in a long tube from
the mouth to the anus. The function of the digestive system is digestion and
absorption. Digestion is the breakdown of food into small molecules, which
are then absorbed into the body. The digestive system is divided into two
major parts:
1-17 Parts of the digestive system
Mouth
The mouth is the beginning of the digestive tract; and, in fact, digestion starts
here when taking the first bite of food. Chewing breaks the food into pieces
that are more easily digested, while saliva mixes with food to begin the
process of breaking it down.
pharynx
the pharynx opens into the larynx and esophagus. It is divided into three
regions according to location: the nasopharynx, the oropharynx, and the
laryngopharynx or hypopharynx.
Esophagus
Located in your throat near your trachea (windpipe), the esophagus receives
food from your mouth when you swallow. By means of a series of muscular
contractions called peristalsis, the esophagus delivers food to your stomach.
Stomach
The stomach is a hollow organ, or "container," that holds food while it is being
mixed with enzymes that continue the process of breaking down food into a
usable form. Cells in the lining of the stomach secrete a strong acid and
powerful enzymes that are responsible for the breakdown process. When the
contents of the stomach are sufficiently processed, they are released into the
small intestine.
Small intestine
Made up of three segments — the duodenum, jejunum, and ileum — the small
intestine is a 22-foot long muscular tube that breaks down food using enzymes
released by the pancreas and bile from the liver. Peristalsis also is at work in
this organ, moving food through and mixing it with digestive secretions from
the pancreas and liver. The duodenum is largely responsible for the
continuous breaking-down process, with the jejunum and ileum mainly
responsible for absorption of nutrients into the bloodstream.
Contents of the small intestine start out semi-solid, and end in a liquid form
after passing through the organ. Water, bile, enzymes, and mucous contribute
47
to the change in consistency. Once the nutrients have been absorbed and the
leftover-food residue liquid has passed through the small intestine, it then
moves on to the large intestine, or colon.
Pancreas
The pancreas secretes digestive enzymes into the duodenum, the first
segment of the small intestine. These enzymes break down protein, fats, and
carbohydrates. The pancreas also makes insulin, secreting it directly into the
bloodstream. Insulin is the chief hormone for metabolizing sugar.
Liver
The liver has multiple functions, but its main function within the digestive
system is to process the nutrients absorbed from the small intestine. Bile from
the liver secreted into the small intestine also plays an important role in
digesting fat. In addition, the liver is the body’s chemical "factory." It takes the
raw materials absorbed by the intestine and makes all the various chemicals
the body needs to function. The liver also detoxifies potentially harmful
chemicals. It breaks down and secretes many drugs.
Gallbladder
The gallbladder stores and concentrates bile, and then releases it into the
duodenum to help absorb and digest fats.
Colon (large intestine)
The colon is a 6-foot long muscular tube that connects the small intestine to
the rectum. The large intestine is made up of the cecum, the ascending (right)
colon, the transverse (across) colon, the descending (left) colon, and the
sigmoid colon, which connects to the rectum. The appendix is a small tube
attached to the cecum. The large intestine is a highly specialized organ that is
responsible for processing waste so that emptying the bowels is easy and
convenient.
Stool, or waste left over from the digestive process, is passed through the
colon by means of peristalsis, first in a liquid state and ultimately in a solid
form. As stool passes through the colon, water is removed. Stool is stored in
the sigmoid (S-shaped) colon until a "mass movement" empties it into the
rectum once or twice a day. It normally takes about 36 hours for stool to get
through the colon. The stool itself is mostly food debris and bacteria. These
bacteria perform several useful functions, such as synthesizing various
vitamins, processing waste products and food particles, and protecting against
harmful bacteria. When the descending colon becomes full of stool, or feces, it
empties its contents into the rectum to begin the process of elimination.
Rectum
The rectum (Latin for "straight") is an 8-inch chamber that connects the colon
to the anus. It is the rectum's job to receive stool from the colon, to let the
person know that there is stool to be evacuated, and to hold the stool until
evacuation happens. When anything (gas or stool) comes into the rectum,
sensors send a message to the brain. The brain then decides if the rectal
contents can be released or not. If they can, the sphincters relax and the
rectum contracts, disposing its contents. If the contents cannot be disposed,
the sphincter contracts and the rectum accommodates so that the sensation
temporarily goes away.
48
Anus
The anus is the last part of the digestive tract. It is a 2-inch long canal
consisting of the pelvic floor muscles and the two anal sphincters (internal and
external). The lining of the upper anus is specialized to detect rectal contents.
It lets you know whether the contents are liquid, gas, or solid. The anus is
surrounded by sphincter muscles that are important in allowing control of
stool. The pelvic floor muscle creates an angle between the rectum and the
anus that stops stool from coming out when it is not supposed to. The internal
sphincter is always tight, except when stool enters the rectum. It keeps us
continent when we are asleep or otherwise unaware of the presence of stool.
When we get an urge to go to the bathroom, we rely on our external sphincter
to hold the stool until reaching a toilet, where it then relaxes to release the
contents.
2-17 functions of stomach
The primary functions of the stomach are digestion and killing bacteria and
breaking down food releasing to the small intestine while maintaining a
constant release rate of material from the stomach to the small intestine. The
pH inside of the stomach is maintained at very acidic levels which help the
digestive enzymes like pepsin break down the material further so it can be
moved to the small intestine successfully. Finally, the stomach is also
responsible for helping the small intestine absorb vitamins.
3-17 Function of the Small Intestine
The small intestine is responsible for absorbing most of the nutrients found
within your food. By the time ingested food reaches the small intestine, it
has been mechanically broken down into a liquid. As this liquid flows
across the inner surface of the small intestine (which has many small folds
to increase the surface area), nutrients within the food come into contact
with the many small blood vessels which surround the small intestine. This
blood then leaves the small intestine, carrying away nutrients, water
electrolytes, vitamins, minerals, fats and medications to the entire body. It
can take three to six hours for a meal to pass from one end of the small
intestine to the other, and that is dependent on the makeup of the food
passing through; meals containing a lot of fiber move more quickly.
49
Unit eighteen
Accessory glands of the digestive system
1-18 salivary glands
The glands are found in and around your mouth and throat. We call the major
salivary glands the parotid, submandibular, and sublingual glands.
They all secrete saliva into your mouth, the parotid through tubes that drain
saliva, called salivary ducts, near your upper teeth, submandibular under your
tongue, and the sublingual through many ducts in the floor of your mouth.
Besides these glands, there are many tiny glands called minor salivary glands
located in your lips, inner cheek area (buccal mucosa), and extensively in other
linings of your mouth and throat.
2-18 Functions of salivary glands
Salivary glands produce the saliva used to moisten your mouth, initiate
digestion, and help protect your teeth from decay.
As a good health measure, it is important to drink lots of liquids daily.
Dehydration is a risk factor for salivary gland disease.
3-18 The Liver
The liver is the largest glandular organ of the body. It weighs about 3 lb (1.36
kg). It is reddish brown in color and is divided into four lobes of unequal size
and shape. The liver lies on the right side of the abdominal cavity beneath the
diaphragm. Blood is carried to the liver via two large vessels called the hepatic
artery and the portal vein. The heptic artery carries oxygen-rich blood from the
aorta (a major vessel in the heart). The portal vein carries blood containing
digested food from the small intestine. These blood vessels subdivide in the
liver repeatedly, terminating in very small capillaries. Each capillary leads to a
lobule. Liver tissue is composed of thousands of lobules, and each lobule is
made up of hepatic cells, the basic metabolic cells of the liver.
4-18 functions of the liver
1- produce substances that break down fats.
2- convert glucose to glycogen.
3- produce urea (the main substance of urine).
4- make certain amino acids (the building blocks of proteins).
50
5- filter harmful substances from the blood (such as alcohol).
6- storage of vitamins and minerals (vitamins A, D, K and B12) .
7- maintain a proper level or glucose in the blood.
8- The liver is also responsible for producing cholesterol. It produces about
80% of the cholesterol in your body
5-18 The pancreas
The pancreas is a glandular organ that secretes digestive enzymes (internal
secretions) and hormones (external secretions). In humans, the pancreas is a
yellowish organ about 7 inches (17.8 cm) long and 1.5 inches. (3.8 cm) wide.
The pancreas lies beneath the stomach and is connected to the small intestine
at the duodenum.
The pancreas contains enzyme producing cells that secrete two hormones.
The two hormones are insulin and glucagon. Insulin and glucagon are secreted
directly into the bloodstream, and together, they regulate the level of glucose
in the blood. Insulin lowers the blood sugar level and increases the amount of
glucagon (stored carbohydrate) in the liver. Glucagon slowly increases the
blood sugar level if it falls too low. If the insulin secreting cells do not work
properly, diabetes occurs.
What else does the Pancreas Do?
The pancreas produces the body's most important enzymes. The enzymes are
designed to digest foods and break down starches.
The pancreas also helps neutralize chyme and helps break down proteins, fats
and starch. Chyme is a thick semifluid mass of partly digested food that is
passed from the stomach to the duodenum. If the pancreas is not working
properly to neutralize chyme and break down proteins, fats and starch,
starvation may occur
51
6-18 The gallbladder
The gallbladder is a small pear-shaped organ that stores and concentrates
bile. The gallbladder is connected to the liver by the hepatic duct. It is
approximately 3 to 4 inches (7.6 to 10.2 cm) long and about 1 inch (2.5 cm)
wide.
What is its Function?
The function of the gallbladder is to store bile and concentrate. Bile is a
digestive liquid continually secreted by the liver. The bile emulsifies fats and
neutralizes acids in partly digested food. A muscular valve in the common bile
duct opens, and the bile flows from the gallbladder into the cystic duct, along
the common bile duct, and into the duodenum (part of the small intestine).
Conditions and Diseases of the gallbladder
Sometimes the substances contained in bile crystallize in the gallbladder,
forming gallstones. These small, hard concretions are more common in
persons over 40, especially in women and the obese. They can cause
inflammation of the gallbladder, a disorder that produces symptoms similar to
those of indigestion, especially after a fatty meal is consumed. If a stone
becomes lodged in the bile duct, it produces severe pain. Gallstones may pass
out of the body spontaneously; however, serious blockage is treated by
removing the gallbladder surgically.
Test No 1
Trace the path of mouthful of food through the digestive tract
Test no. 2
Name the accessory organs of digestion and the function of each
52
Unit nineteen
1-19 The treatment of food in the digestive system involves
the following seven processes:







Ingestion is the process of eating.
Propulsion is the movement of food along the digestive tract. The major
means of propulsion is peristalsis, a series of alternating contractions
and relaxations of smooth muscle that lines the walls of the digestive
organs and that forces food to move forward.
Secretion of digestive enzymes and other substances liquefies, adjusts
the pH of, and chemically breaks down the food.
Mechanical digestion is the process of physically breaking down food
into smaller pieces. This process begins with the chewing of food and
continues with the muscular churning of the stomach. Additional
churning occurs in the small intestine through muscular constriction of
the intestinal wall. This process, called segmentation, is similar to
peristalsis, except that the rhythmic timing of the muscle constrictions
forces the food backward and forward rather than forward only.
Chemical digestion is the process of chemically breaking down food
into simpler molecules. The process is carried out by enzymes in the
stomach and small intestines.
Absorption is the movement of molecules (by passive diffusion or
active transport) from the digestive tract to adjacent blood and
lymphatic vessels. Absorption is the entrance of the digested food into
the body.
Defecation is the process of eliminating undigested material through the
anus.
2-19 Carbohydrates digestion
Carbohydrate
are one of three macronutrients that provide the body with energy ( protein and
fats being the other two). The chemical compounds in carbohydrates are found
in both simple and complex forms, and in order for the body to use
carbohydrates for energy, food must undergo digestion, absorption , and
glycolysis . It is recommended that 55 to 60 percent of caloric intake come
from carbohydrates.
Chemical Structure
Carbohydrates are a main source of energy for the body and are made of
carbon, hydrogen, and oxygen .
Humans obtain carbohydrates by eating foods that contain them. In order to
use the energy contained in the carbohydrates, humans must metabolize , or
53
break down, the structure of the molecule in a process that is opposite that of
photosynthesis. It starts with the carbohydrate and oxygen and produces
carbon dioxide, water, and energy. The body utilizes the energy and water and
rids itself of the carbon dioxide.
3-19 Digestion and Absorption
Carbohydrates must be digested and absorbed in order to transform them into
energy that can be used by the body. Food preparation often aids in the
digestion process. When starches are heated, they swell and become easier for
the body to break down. In the mouth, the enzyme amylase, which is contained
in saliva, mixes with food products and breaks some starches into smaller
units. However, once the carbohydrates reach the acidic environment of the
stomach, the amylase is inactivated. After the carbohydrates have passed
through the stomach and into the small intestine, key digestive enzymes are
secreted from the pancreas and the small intestine where most digestion and
absorption occurs. Pancreatic amylase breaks starch into disaccharides and
small polysaccharides, and enzymes from the cells of the small-intestinal wall
break any remaining disaccharides into their monosaccharide components.
Dietary fiber is not digested by the small intestine; instead, it passes to the
colon unchanged.
Sugars such as galactose, glucose, and fructose that are found naturally in
foods or are produced by the breakdown of polysaccharides enter into
absorptive intestinal cells. After absorption, they are transported to the liver
where galactose and fructose are converted to glucose and released into the
bloodstream. The glucose may be sent directly to organs that need energy, it
may be transformed into glycogen (in a process called glycogenesis) for
storage in the liver or muscles, or it may be converted to and stored as fat.
Glycolysis
The molecular bonds in food products do not yield high amounts of energy
when broken down. Therefore, the energy contained in food is released within
cells and stored in the form of adenosine triphosphate (ATP), a high-energy
compound created by cellular energy-production systems. Carbohydrates are
54
metabolized and used to produce ATP molecules through a process called
glycolysis.
Glycolysis breaks down glucose or glycogen into pyruvic acid through
enzymatic reactions within the cytoplasm of the cells. The process results in
the formation of three molecules of ATP (two, if the starting product was
glucose). Without the presence of oxygen, pyruvic acid is changed to lactic
acid , and the energy-production process ends. However, in the presence of
oxygen, larger amounts of ATP can be produced. In that situation, pyruvic acid
is transformed into a chemical compound called acetyle coenzyme A, a
compound that begins a complex series of reactions in the Krebs Cycle and
the electron transport system. The end result is a net gain of up to thirty-nine
molecules of ATP from one molecule of glycogen (thirty-eight molecules of
ATP if glucose was used). Thus, through certain systems, glucose can be used
very efficiently in the
4-19 Digestion Of Protein
Protein--like meat, fish, eggs, milk products, some vegetables, nuts, etc,--are
long chains of amino acids. The types and arrangements of these amino acids
determine the characteristics of the protein. The important digestive enzyme of
the stomach, pepsin, is most active at a pH of about 2 and totally inactive at a
pH above approximately 5. So, for pepsin to affect any digestive action on
protein, the stomach juices must be acidic. Hydrochloric acid provides the acid
environment. It is excreted by parietal cells at a pH of about 0.8, but after being
mixed with the stomach contents and secretions of other glandular cells of the
stomach, the pH ranges around 2 or 3. This is ideal and imperative for pepsin
activity. Pepsin can essentially digest any protein in the diet. Even collagen,
present, for example, in connective tissue of meat, can be digested by pepsin
even though other digestive enzymes cannot affect it. Collagen fibers must be
digested before the cellular protein of the meat can be digested. Lacking
sufficient hydrochloric acid or pepsin, protein foods are poorly penetrated by
other digestive enzymes further on and are thus poorly digested. After leaving
the lower stomach, protein has been broken down from long protein molecules
into shorter strings of amino acids (the building blocks of protein). As soon as
these partially broken-down products enter the small intestine, they are
"attacked" by pancreatic enzymes like trypsin, chymotrypsin and
carboxypolypeptidase. These enzymes break down the protein even more,
some to even the final stage of individual amino acids. Simply, it would be like
taking apart, piece by piece, a child's toysseparating the combination of
pieces. The walls of the small intestine contain and use several different
enzymes for final breakdown.
All the proteolytic (hastening protein breakdown) enzymes--including those of
the stomach, pancreatic juice and intestinal lining--are very specific for the
breaking down of individual protein combinations. A specific enzyme is
55
needed for each specific type of amino acid-linkage. That's why there are so
many enzymes and why all the digestive enzymes are needed. When food is
properly chewed, not eaten to excess at one time and the digestive juices are
allowed to function as they should, about 98 percent of all protein is totally
broken down to individual amino acids or pairs or short strings of them
(polypeptides). Now the intestine can absorb them. The enzymes in the small
intestine require a slightly alkaline environment to work. Since the food coming
from the stomach is (or should be) an acid mix, the pancreas pours a strongly
alkaline juice into the duodenum (the first part of the small intestine).
Absorption Of Protein
Most protein is absorbed in the form of single amino acids (the building blocks
of protein), but some are absorbed as two or three amino-acid combinations.
The different types of amino acids are absorbed selectively, and absorption is
rapid; as soon as "free" individual amino acids are isolated or fractionated,
they are absorbed.
5-19 Digestion Of Fat
Fat in the diet is most commonly triglycerides or neutral fat found in both
animals and plants. Cholesterol, cholesterol-compounds and phospholipids
also are normal fats in foods. Because a large quantity of fat dumped into the
blood stream at one time is deleterious to health and might fatally clog the
circulatory system, a mechanism for retardation of stomach emptying of fat is
present. When a bit of fat enters the duodenum, a chemical message is sent to
the brain which then signals the stomach to cease releasing more material into
the duodenum until it has taken care of the fat. Fat may stay in the stomach for
four hours or longer, producing at the time a sensation of satiety (filled up) but
rendering fermentation more likely. Since fermentation products irritate the
stomach, and an irritated stomach subsequently evokes a greater sensation of
hunger, the practice of eating fats for satiety is self-defeating. Fats clog the
digestion. Much pain and indigestion have their origin with fats eaten. Only a
small amount of fat is digested in the stomach by gastric lipase, a fat-splitting
enzyme. Essentially, most fat digestion occurs in the small intestine. First, the
fat globules must be broken into small sizes so enzymes can act. This
emulsification is accomplished under the influence of bile, a secretion of the
liver. Bile is stored in the gallbladder and drawn upon as needed. Bile contains
a large amount of bile salts, the main function of which is to make fat globules
break down. This is similar to the action of some household detergents that
remove grease.
The "detergent" function of bile salts is essential to fat digestion, for the lipase
(fat-splitting enzymes) can "attack" the fat globules only on their surfaces. The
smaller the fat particles, the better digestion. Pancreatic lipase is the most
important enzyme in fat digestion. In concert, the epithelial lining of the small
intestine also releases a small amount of lipase. Both lipases (pancreatic and
intestinal) act to digest fat. Bile salts also form micelles, small sphericle
globules. These micelles help remove the end products of fat digestion so
further fat digestion can continue. These little micelles transport their cargo to
the lining of the small intestine, where they're absorbed. The bile salts then
return for more cargo, thus providing a "ferry service." So important are bile
salts that, when in adequate supply, about 97 percent of fat is absorbed. If
insufficient, only 50 to 60 percent is absorbed.
56
Absorption Of Fat
Upon contacting the membrane lining of the small intestine, the end products
of fat digestion become dissolved in the membrane and diffuse to the interior
of the cell. As the split fat molecules enter the lining cells, intestinal lipase
(enzyme) helps to further digest them. Triglycerides are formed in these cells
and, along with cholesterol and phospholipids (other absorbed fat), they are
given a protein coat. Thus "dressed," these final fat products pass into spaces
between the cells and into the villi. Most of these fatty acids are then propelled,
along with lymph (a fluid) by the lymphatic pump system. About 80 to 90
percent of digested fat is absorbed in this manner. Small amounts of fatty
acids are absorbed directly into the blood going to the liver.
Test no. 1
Name the food in four basic food groups
Test No. 2
Explain the treatment of food in digestive system
57
Unit twenty
The nervous system
1-20 The nerve cells
The nervous system composed of nerve cells, or neurons:
Motor Neurone:

Efferent Neuron – Moving toward a central organ or point

Relays messages from the brain or spinal cord to the muscles and
organs
Sensory Neurone:

Afferent Neuron – Moving away from a central organ or point

Relays messages from receptors to the brain or spinal cord
58
Neurons are similar to other cells in the body because:
Interneuron (relay neurone):

Relays message from sensory neurone to motor neurone

Make up the brain and spinal cord
There are several differences between axons and dendrites:
Axons

Dendrites

Take information away from the
cell body
Bring information to the cell
body

Smooth Surface


Generally only 1 axon per cell

No ribosomes

Usually many dendrites per cell

Can have myelin

Have ribosomes

Branch further from the cell

No myelin insulation
body

Branch near the cell body
Rough Surface (dendritic
spines)
59
1. Neurons are surrounded by a cell membrane.
2. Neurons have a nucleus that contains genes.
3. Neurons contain cytoplasm, mitochondria and other organelles.
4. Neurons carry out basic cellular processes such as protein synthesis and energy production.
Neurons differ from other cells in the body because:
1. Neurons have specialized extensions called dendrites and axons. Dendrites bring information
to the cell body and axons take information away from the cell body.
2. Neurons communicate with each other through an electrochemical process.
3. Neurons contain some specialized structures (for example, synapses) and chemicals (for
example, neurotransmitters).
Humans have three types of neurons:

Sensory neurons have long axons and transmit nerve impulses from
sensory receptors all over the body to the central nervous system.

Motor neurons also have long axons and transmit nerve impulses from the
central nervous system to effectors (muscles and glands) all over the body.

Interneurones (also called connector neurons or relay neurons) are usually
much smaller cells, with many interconnections
60
The three types of neurons are arranged in circuits and networks, the simplest
of which is the reflex arc.
Reflex arc can also be represented by a simple flow diagram:
2-20 The organization of nervous system
. The organization of the human nervous system is shown in this diagram:
61
It is easy to forget that much of the human nervous system is concerned with routine,
involuntary jobs, such as homeostasis, digestion, posture, breathing, etc. This is the
job of the autonomic nervous system, and its motor functions are split into two
divisions, with anatomically distinct neurones. Most body organs are innervated by
two separate sets of motor neurones; one from the sympathetic system and one from
the parasympathetic system. These neurones have opposite (or antagonistic) effects.
In general the sympathetic system stimulates the “fight or flight” responses to
threatening situations, while the parasympathetic system relaxes the body. The details
are listed in this table:-
Organ
Sympathetic System
Eye
Dilates pupil
Tear glands
No effect
Salivary glands
Inhibits saliva production
Lungs
Dilates bronchi
Heart
Speeds up heart rate
Gut
Inhibits peristalsis
Liver
Stimulates glucose production
Bladder
Inhibits urination
Parasympathetic System
Constricts pupil
Stimulates tear secretion
Stimulates saliva production
Constricts bronchi
Slows down heart rate
Stimulates peristalsis
Stimulates bile production
Stimulates urination
Test No 1
List the types of neurons
Test no . 2
What are the differences between axons and Dendrites
62
Unit twenty one
1-21 The central nervous system
The central nervous system is made up by

spinal cord and brain
The spinal cord ( functions )



conducts sensory information from the peripheral nervous system (both
somatic and autonomic) to the brain
conducts motor information from the brain to our various effectors
o skeletal muscles
o cardiac muscle
o smooth muscle
o glands
serves as a minor reflex center
The brain (functions )


receives sensory input from the spinal cord as well as from its own
nerves (e.g., olfactory and optic nerves)
devotes most of its volume (and computational power) to processing its
various sensory inputs and initiating appropriate — and coordinated —
motor outputs.
Both the spinal cord and the brain consist of


white matter = bundles of axons each coated with a sheath of myelin
gray matter = masses of the cell bodies and dendrites — each covered
with synapses.
In the spinal cord, the white matter is at the surface, the gray matter inside. .
The Meninges
Both the spinal cord and brain are covered in three continuous sheets of
connective tissue, the meninges. From outside in, these are the



dura mater — pressed against the bony surface of the interior of the
vertebrae and the cranium
the arachnoid
the pia mater
The region between the arachnoid and pia mater is filled with cerebrospinal
fluid (CSF).
63
2-21 the spinal cord
31 pairs of spinal nerves arise along the spinal cord. These are "mixed" nerves
because each contain both sensory and motor axons. However, within the
spinal column,


all the sensory axons pass into the dorsal root ganglion where their cell
bodies are located and then on into the spinal cord itself.
all the motor axons pass into the ventral roots before uniting with the
sensory axons to form the mixed nerves.
The spinal cord carries out two main functions:


It connects a large part of the peripheral nervous system to the brain.
Information (nerve impulses) reaching the spinal cord through sensory
neurons are transmitted up into the brain. Signals arising in the motor
areas of the brain travel back down the cord and leave in the motor
neurons.
The spinal cord also acts as a minor coordinating center responsible for
some simple reflexes like the withdrawal reflex.
The interneurons carrying impulses to and from specific receptors and
effectors are grouped together in spinal tracts.
Crossing Over of the Spinal Tracts
Impulses reaching the spinal cord from the left side of the body eventually
pass over to tracts running up to the right side of the brain and vice versa. In
some cases this crossing over occurs as soon as the impulses enter the cord.
In other cases, it does not take place until the tracts enter the brain itself.
3-21The Brain



forebrain
midbrain
hindbrain.
The human brain receives nerve impulses from


the spinal cord and
12 pairs of cranial nerves
o Some of the cranial nerves are "mixed", containing both sensory
and motor axons
o Some, e.g., the optic and olfactory nerves (numbers I and II)
contain sensory axons only
o Some, e.g. number III that controls eyeball muscles, contain
motor axons only.
64
The Hindbrain
The main structures of the hindbrain are the



medulla oblongata
pons and
cerebellum
Medulla oblongata
The medulla looks like a swollen tip to the spinal cord. Nerve impulses arising
here



rhythmically stimulate the intercostal muscles and diaphragm — making
breathing possible
regulate heartbeat
regulate the diameter of arterioles thus adjusting blood flow.
The neurons controlling breathing have mu (µ) receptors, the receptors to
which opiates, like heroin, bind. This accounts for the suppressive effect of
opiates on breathing. Destruction of the medulla causes instant death.
Pons
The pons seems to serve as a relay station carrying signals from various parts
of the cerebral cortex to the cerebellum. Nerve impulses coming from the eyes,
ears, and touch receptors are sent on the cerebellum. The pons also
participates in the reflexes that regulate breathing.
The reticular formation is a region running through the middle of the hindbrain
(and on into the midbrain). It receives sensory input (e.g., sound) from higher
in the brain and passes these back up to the thalamus. The reticular formation
is involved in sleep, arousal (and vomiting).
65
Cerebellum
The cerebellum consists of two deeply-convoluted hemispheres. Although it
represents only 10% of the weight of the brain, it contains as many neurons as
all the rest of the brain combined.
Its most clearly-understood function is to coordinate body movements. People
with damage to their cerebellum are able to perceive the world as before and to
contract their muscles, but their motions are jerky and uncoordinated.
So the cerebellum appears to be a center for learning motor skills (implicit
memory). Laboratory studies have demonstrated both long-term potentiation
(LTP) and long-term depression (LTD) in the cerebellum.
The Midbrain
The midbrain (mesencephalon) occupies only a small region in humans). We
shall look at only three features:



the reticular formation: collects input from higher brain centers and
passes it on to motor neurons.
the substantia nigra: helps "smooth" out body movements; damage to
the substantia nigra causes Parkinson's disease.
the ventral tegmental area (VTA): packed with dopamine-releasing
neurons that
o are activated by nicotinic acetylcholine receptors and
o whose projections synapse deep within the forebrain.
The VTA seems to be involved in pleasure: nicotine, amphetamines and
cocaine bind to and activate its dopamine-releasing neurons and this
may account — at least in part (see below)— for their addictive qualities.
Forebrain
The human forebrain is made up of


a pair of large cerebral hemispheres, called the telencephalon. Because
of crossing over of the spinal tracts, the left hemisphere of the forebrain
deals with the right side of the body and vice versa.
a group of structures located deep within the cerebrum, that make up
the diencephalon.
Diencephalon
We shall consider four of its structures: the

Thalamus.
o All sensory input (except for olfaction) passes through these
paired structures on the way up to the somatic-sensory regions
of the cerebral cortex and then returns to them from there.
o signals from the cerebellum pass through them on the way to the
motor areas of the cerebral cortex.
66



Lateral geniculate nucleus (LGN). All signals entering the brain from
each optic nerve enter a LGN and undergo some processing before
moving on the various visual areas of the cerebral cortex.
Hypothalamus.
o The seat of the autonomic nervous system. Damage to the
hypothalamus is quickly fatal as the normal homeostasis of body
temperature, blood chemistry, etc. goes out of control.
o The source of 8 hormones, two of which pass into the posterior
lobe of the pituitary gland.
The Cerebral Hemispheres
Each hemisphere of the cerebrum is
subdivided into four lobes visible from
the outside:




frontal
parietal
occipital
temporal
Test no 1
Enumerate the functions of spinal cord
Test no. 2
What are the parts of brain
67
Unit twenty two
1-22 Peripheral Nervous System
The peripheral nervous system is divided into the following sections:
Peripheral Nervous System

Sensory Nervous System - sends information to the CNS from
internal organs or from external stimuli.

Motor Nervous System - carries information from the CNS to
organs, muscles, and glands.
o
Somatic Nervous System - controls skeletal muscle as well
as external sensory organs.
o
Autonomic Nervous System - controls involuntary muscles,
such as smooth and cardiac muscle.

Sympathetic - controls activities that increase energy
expenditures.

Parasympathetic - controls activities that conserve
energy expenditures.
68
Sympathetic
Rate increased
Force increased
Bronchial muscle
relaxed
Pupil dilation
Motility reduced
Sphincter closed
Decreased urine
secretion
Structure
Heart
Heart
Parasympathetic
Rate decreased
Force decreased
Bronchial muscle
contracted
Pupil constriction
Digestion increased
Sphincter relaxed
Increased urine
secretion
Lungs
Eye
Intestine
Bladder
Kidneys
69
Unit twenty three
The Male reproductive system
Organs of the male reproductive system are specialized for the following
functions:



To produce, maintain and transport sperm (the male reproductive cells) and
protective fluid (semen)
To discharge sperm within the female reproductive tract
To produce and secrete male sex hormones
The male reproductive anatomy includes internal and external structures.
1-23 The external reproductive structures
Most of the male reproductive system is located outside of the man’s body.
The external structures of the male reproductive system are the penis, the
scrotum and the testicles.
1- Penis — The penis is the male organ for sexual intercourse. It has three
parts: the root, which attaches to the wall of the abdomen; the body, and the
glans, which is the cone-shaped end of the penis. The glans, which also is
called the head of the penis, is covered with a loose layer of skin called
foreskin. (This skin is removed in a procedure called circumcision.) The
opening of the urethra, the tube that transports semen and urine, is at the tip of
the glans penis. The penis also contains a number of sensitive nerve endings.
Semen, which contains sperm, is expelled (ejaculated) through the end of the
penis when the man reaches sexual climax (orgasm). When the penis is erect,
the flow of urine is blocked from the urethra, allowing only semen to be
ejaculated at orgasm.
2- Scrotum — The scrotum is the loose pouch-like sac of skin that hangs
behind the penis. It contains the testicles (also called testes), as well as many
nerves and blood vessels.
The scrotum has a protective function and acts as a climate control system for
the testes. For normal sperm development, the testes must be at a temperature
slightly cooler than the body temperature. Special muscles in the wall of the
scrotum allow it to contract and relax, moving the testicles closer to the body
for warmth and protection or farther away from the body to cool the
temperature.
3-Testicles (testes) — The testes are oval organs about the size of large olives
that lie in the scrotum, secured at either end by a structure called the
spermatic cord. Most men have two testes.
The testes are responsible for making testosterone, the primary male sex
hormone, and for generating sperm. Within the testes are coiled masses of
tubes called seminiferous tubules.
70
These tubules are responsible for producing the sperm cells through a
process called spermatogenesis.
4-Epididymis — The epididymis is a long, coiled tube that rests on the
backside of each testicle. It functions in the transport and storage of the sperm
cells that are produced in the testes. It also is the job of the epididymis to bring
the sperm to maturity, since the sperm that emerge from the testes are
immature and incapable of fertilization. During sexual arousal, contractions
force the sperm into the vas deferens.
2-23 The internal reproductive organs
The internal organs of the male reproductive system, also called accessory
organs, include the following:
1. Vas deferens — The vas deferens is a long, muscular tube that travels
2.
3.
4.
5.
6.
from the epididymis into the pelvic cavity, to just behind the bladder.
The vas deferens transports mature sperm to the urethra in preparation
for ejaculation.
Ejaculatory ducts — These are formed by the fusion of the vas deferens
and the seminal vesicles. The ejaculatory ducts empty into the urethra.
Urethra — The urethra is the tube that carries urine from the bladder to
outside of the body. In males, it has the additional function of expelling
(ejaculating) semen when the man reaches orgasm. When the penis is
erect during sex, the flow of urine is blocked from the urethra, allowing
only semen to be ejaculated at orgasm.
Seminal vesicles — The seminal vesicles are sac-like pouches that
attach to the vas deferens near the base of the bladder. The seminal
vesicles produce a sugar-rich fluid (fructose) that provides sperm with a
source of energy and helps with the sperms’ motility (ability to move).
The fluid of the seminal vesicles makes up most of the volume of a
man’s ejaculatory fluid, or ejaculate.
Prostate gland — The prostate gland is a walnut-sized structure that is
located below the urinary bladder in front of the rectum. The prostate
gland contributes additional fluid to the ejaculate. Prostate fluids also
help to nourish the sperm. The urethra, which carries the ejaculate to be
expelled during orgasm, runs through the center of the prostate gland.
Bulbourethral glands — The bulbourethral glands, or Cowper’s glands,
are pea-sized structures located on the sides of the urethra just below
the prostate gland. These glands produce a clear, slippery fluid that
empties directly into the urethra. This fluid serves to lubricate the
urethra and to neutralize any acidity that may be present due to residual
drops of urine in the urethra.
3-23 How does the male reproductive system function?
The entire male reproductive system is dependent on hormones, which are
chemicals that stimulate or regulate the activity of cells or organs. The primary
hormones involved in the functioning of the male reproductive system are
follicle-stimulating hormone (FSH), luteinizing hormone (LH) and testosterone.
71
FSH and LH are produced by the pituitary gland located at the base of the
brain. FSH is necessary for sperm production (spermatogenesis), and LH
stimulates the production of testosterone, which is necessary to continue the
process of spermatogenesis. Testosterone also is important in the
development of male characteristics, including muscle mass and strength, fat
distribution, bone mass and sex drive.
Does a man go through menopause?
Menopause is a term used to describe the end of a woman's normal menstrual
function. Female menopause is characterized by changes in hormone
production. The testes, unlike the ovaries, do not lose the ability to make
hormones. If a man is healthy, he may be able to make sperm well into his 80s
or longer.
On the other hand, subtle changes in the function of the testes may occur as
early as 45 to 50 years of age, and more dramatically after the age of 70. For
many men, hormone production may remain normal into old age, while others
may have declining hormone production earlier on, sometimes as a result of an
illness, such as diabetes.
Test no. 1
Enumerate the internal organs of male reproductive system
72
Unit twenty four
The female reproductive system
1-24 functions
1- It produces the female egg cells necessary for reproduction, called the ova
or oocytes.
2- transport the ova to the site of fertilization.
3- Conception, the fertilization of an egg by a sperm, normally occurs in the
fallopian tubes.
4- After conception, the uterus offers a safe and favorable environment for a
baby to develop before it is time for it to make its way into the outside world.
5- If fertilization does not take place, the system is designed to menstruate
(the monthly shedding of the uterine lining).
6- the female reproductive system produces female sex hormones that
maintain the reproductive cycle.
During menopause the female reproductive system gradually stops making the
female hormones necessary for the reproductive cycle to work. When the body
no longer produces these hormones a woman is considered to be menopausal.
2-24 female reproductive anatomy includes internal and external structures.
1- external reproductive organs
The function of the external female reproductive structures (the genital) is
twofold: To enable sperm to enter the body and to protect the internal genital
organs from infectious organisms. The main external structures of the female
reproductive system include:




Labia majora: The labia majora enclose and protect the other external
reproductive organs
Labia minora: Literally translated as "small lips," the labia minora can
be very small or up to 2 inches wide. They lie just inside the labia
majora, and surround the openings to the vagina (the canal that joins
the lower part of the uterus to the outside of the body) and urethra (the
tube that carries urine from the bladder to the outside of the body).
Bartholin’s glands: These glands are located next to the vaginal
opening and produce a fluid (mucus) secretion.
Clitoris: The two labia minora meet at the clitoris, a small, sensitive
protrusion that is comparable to the penis in males. The clitoris is
covered by a fold of skin, called the prepuce,
73
2- The internal reproductive organs include:




Vagina: The vagina is a canal that joins the cervix (the lower part of
uterus) to the outside of the body. It also is known as the birth canal.
Uterus ;- The uterus is a hollow, pear-shaped organ that is the home to a
developing fetus. The uterus is divided into two parts: the cervix, which
is the lower part that opens into the vagina, and the main body of the
uterus, called the corpus. The corpus can easily expand to hold a
developing baby. A channel through the cervix allows sperm to enter
and menstrual blood to exit.
Ovaries: The ovaries are small, oval-shaped glands that are located on
either side of the uterus. The ovaries produce eggs and hormones.
Fallopian tubes: These are narrow tubes that are attached to the upper
part of the uterus and serve as tunnels for the ova (egg cells) to travel
from the ovaries to the uterus. Conception, the fertilization of an egg by
a sperm, normally occurs in the fallopian tubes. The fertilized egg then
moves to the uterus, where it implants to the uterine wall.
3-24 What happens during the menstrual cycle?
Females of reproductive age (anywhere from 11-16 years) experience cycles of
hormonal activity that repeat at about one-month intervals. (Menstru means
"monthly"; hence the term menstrual cycle.) With every cycle, a woman’s body
prepares for a potential pregnancy, whether or not that is the woman’s
intention. The term menstruation refers to the periodic shedding of the uterine
lining.
The average menstrual cycle takes about 28 days and occurs in phases: the
follicular phase, the ovulatory phase (ovulation), and the luteal phase.
There are four major hormones (chemicals that stimulate or regulate the
activity of cells or organs) involved in the menstrual cycle: follicle-stimulating
hormone, luteinizing hormone, estrogen, and progesterone.
Follicular phase
This phase starts on the first day of your period. During the follicular phase of
the menstrual cycle, the following events occur:




Two hormones, follicle stimulating hormone (FSH) and luteinizing
hormone (LH) are released from the brain and travel in the blood to the
ovaries.
The hormones stimulate the growth of about 15-20 eggs in the ovaries
each in its own "shell," called a follicle.
These hormones (FSH and LH) also trigger an increase in the
production of the female hormone estrogen.
As estrogen levels rise, like a switch, it turns off the production of
follicle-stimulating hormone. This careful balance of hormones allows
74

the body to limit the number of follicles that complete maturation, or
growth.
As the follicular phase progresses, one follicle in one ovary becomes
dominant and continues to mature. This dominant follicle suppresses all
of the other follicles in the group. As a result, they stop growing and die.
The dominant follicle continues to produce estrogen.
Ovulatory phase
The ovulatory phase, or ovulation, starts about 14 days after the follicular
phase started. The ovulatory phase is the midpoint of the menstrual cycle, with
the next menstrual period starting about 2 weeks later. During this phase, the
following events occur:




The rise in estrogen from the dominant follicle triggers a surge in the
amount of luteinizing hormone that is produced by the brain.
This causes the dominant follicle to release its egg from the ovary.
As the egg is released (a process called ovulation) it is captured by
finger-like projections on the end of the fallopian tubes (fimbriae). The
fimbriae sweep the egg into the tube.
Also during this phase, there is an increase in the amount and thickness
of mucus produced by the cervix (lower part of the uterus.) If a woman
were to have intercourse during this time, the thick mucus captures the
man's sperm, nourishes it, and helps it to move towards the egg for
fertilization.
Luteal phase
The luteal phase begins right after ovulation and involves the following
processes:




Once it releases its egg, the empty follicle develops into a new structure
called the corpus luteum.
The corpus luteum secretes the hormones estrogen and progesterone.
Progesterone prepares the uterus for a fertilized egg to implant.
If intercourse has taken place and a man's sperm has fertilized the egg
(a process called conception), the fertilized egg (embryo) will travel
through the fallopian tube to implant in the uterus. The woman is now
considered pregnant.
If the egg is not fertilized, it passes through the uterus. Not needed to
support a pregnancy, the lining of the uterus breaks down and sheds,
and the next menstrual period begins.
How many eggs does a woman have?
During fetal life, there are about 6 million to 7 million eggs. From this time, no
new eggs are produced.
Test No. 1
Explain the functions of female reproductive system
75
Unit twenty five
1-25 The endocrine glands
Glands are small but powerful organs that are located throughout the
body. They control very important body functions by releasing
hormones.
Endocrine glands
are glands of the endocrine system that secrete their products, hormones,
directly into the blood rather than through a duct. The hypothalamus is a
neuroendocrine organ. Other organs which are not so well known for their
endocrine activity include the stomach, which produces such hormones as
ghrelin
76
The following list of glands make up the endocrine system.









Pituitary Gland
Thymus
Pineal Gland
Testes
Ovaries
Thyroid
Adrenal Glands
Parathyroid
Pancreas
2-25 Pituitary Gland
The pituitary gland is sometimes called the "master gland" because of its great
influence on the other body organs. Its function is complex and important for
overall well-being.
The pituitary gland is divided into two parts, front (anterior) and back
(posterior).
The anterior pituitary produces several types of hormones:






Prolactin or PRL - PRL stimulates milk production from a woman's
breasts after childbirth
Growth hormone or GH - GH stimulates growth in childhood and is
important for maintaining a healthy body composition.
Adrenocorticotropin or ACTH - ACTH stimulates production of cortisol
by the adrenal glands. Cortisol, a so-called "stress hormone," is vital to
survival. It helps maintain blood pressure and blood glucose levels.
Thyroid-stimulating hormone or TSH - TSH stimulates the thyroid gland
to make thyroid hormones, which, in turn, control (regulate) the body's
metabolism, energy, growth and development, and nervous system
activity.
Luteinizing hormone or LH - LH regulates testosterone in men and
estrogen in women.
Follicle-stimulating hormone or FSH - FSH promotes sperm production
in men and stimulates the ovaries to release eggs (ovulate) in women.
LH and FSH work together to allow normal function of the ovaries or
testes.
The posterior pituitary produces two hormones:


Oxytocin - Oxytocin causes milk letdown in nursing mothers and
contractions during childbirth.
Antidiuretic hormone or ADH - ADH, also called vasopressin, is stored
in the back part of the pituitary gland and regulates water balance. If this
hormone is not secreted properly, this can lead to problems of sodium
(salt) and water balance, and could also affect the kidneys so that they
do not work as well.
77
In response to over- or underproduction of pituitary hormones, the target
glands affected by these hormones can produce too many or too few
hormones of their own, leading to hormone imbalance. For example, too much
growth hormone can cause gigantism, or excessive growth (referred to as
acromegaly in adults), while too little GH may cause dwarfism.
3-25 Thymus
The thymus is a gland needed early in life for normal immune function. It is
very large just after a child is born and weighs its greatest when a child
reaches puberty. Then its tissue is replaced by fat. The thymus gland secretes
hormones called humoral factors. These hormones help to develop the
lymphoid system, which is a system throughout the body that help it to reach a
mature immune response in cells to protect them from invading bodies, like
bacteria.
4-25 Pineal Gland
Scientists are still learning how the pineal gland works. They have found one
hormone so far that is produced by this gland: melatonin. Melatonin may stop
the action of (inhibit) the hormones that produce gonadotropin, which causes
the ovaries and testes to develop and function. It may also help to control
sleep patterns.
5-25 Testes
Males have twin reproductive glands, called testes, that produce the hormone
testosterone. Testosterone helps a boy develop and then maintain his sexual
traits. During puberty, testosterone helps to bring about the physical changes
that turn a boy into an adult male, such as growth of the penis and testes,
growth of facial and pubic hair, deepening of the voice, increase in muscle
mass and strength, and increase in height. Throughout adult life, testosterone
helps maintain sex drive, sperm production, male hair patterns, muscle mass,
and bone mass.
6-25 Ovaries
The two most important hormones of a woman's twin reproductive glands, the
ovaries, are estrogen and progesterone. These hormones are responsible for
developing and maintaining female sexual traits, as well as maintaining a
pregnancy. Along with the pituitary gonadotropins (luteinizing hormone or LH
and follicle-stimulating hormone or FSH), they also control the menstrual
cycle. The ovaries also produce inhibit, a protein that curbs (inhibits) the
release of follicle-stimulating hormone from the anterior pituitary and helps
control egg development.
Test no. 1
Name the female and sex hormones and briefly describe what each does
Test no. 2
Where is pineal gland located ? what is the main hormones ,and what dose it
do
78
Unit twenty sex
1-26 Thyroid
The thyroid is a small gland inside the neck, located in front of your breathing
airway (trachea) and below your Adam's apple. The thyroid hormones control
your metabolism, which is the body's ability to break down food and store it as
energy and the ability to break down food into waste products with a release of
energy in the process. The thyroid produces two hormones, T3 (called triiodothyronine) and T4 (called thyroxine)
2-26 Adrenal Glands
Each adrenal gland is actually two endocrine organs. The outer portion is
called the adrenal cortex. The inner portion is called the adrenal medulla. The
hormones of the adrenal cortex are essential for life. The types of hormones
secreted by the adrenal medulla are not.
The adrenal cortex produces glucocorticoids (such as cortisol) that help the
body control blood sugar, increase the burning of protein and fat, and respond
to stressors like fever, major illness, and injury. The mineralcorticoids (such as
aldosterone) control blood volume and help to regulate blood pressure by
acting on the kidneys to help them hold onto enough sodium and water. The
adrenal cortex also produces some sex hormones, which are important for
some secondary sex characteristics in both men and women.
Two important disorders caused by problems with the adrenal cortex are
Cushing's syndrome and Addison's disease. Cushing's syndrome is the result
of too much cortisol, and Addison's disease occurs when there is too little
cortisol.
The adrenal medulla produces epinephrine (adrenaline), which is secreted by
nerve endings and increases the heart rate, opens airways to improve oxygen
intake, and increases blood flow to muscles, usually when a person is scared,
excited, or under stress.
Norepinephrine also is made by the adrenal medulla, but this hormone is more
related to maintaining normal activities as opposed to emergency reactions.
Too much norepinephrine can cause high blood pressure.
3-26 Parathyroid
Located behind the thyroid gland are four tiny parathyroid glands. These make
hormones that help control calcium and phosphorous levels in the body. The
parathyroid glands are necessary for proper bone development. In response to
too little calcium in the diet, the parathyroid glands make parathyroid hormone,
or PTH, that takes calcium from bones so that it will be available in the blood
for nerve conduction and muscle contraction. If the parathyroids are removed
during a thyroid operation, low blood calcium will result in symptoms such as
irregular heartbeat, muscle spasms, tingling in the hands and feet, and
possibly difficulty breathing. A tumor or chronic illness can cause too much
79
secretion of PTH and lead to bone pain, kidney stones, increased urination,
muscle weakness, and fatigue.
4-26 Pancreas
The pancreas is a large gland behind your stomach that helps the body to
maintain healthy blood sugar (glucose) levels. The pancreas secretes insulin, a
hormone that helps glucose move from the blood into the cells where it is used
for energy. The pancreas also secretes glucagon when the blood sugar is low.
Glucagon tells the liver to release glucose, stored in the liver as glycogen, into
the bloodstream.
Diabetes, an imbalance of blood sugar levels, is the major disorder of the
pancreas. There are two types of diabetes. Type I, and Type II diabetes. Type I
diabetes occurs when the pancreas does not produce enough insulin. Type II
diabetes occurs when the body is resistant to the insulin in the blood). Without
enough insulin to keep glucose moving through the metabolic process, the
blood glucose level rises too high.
In Type I diabetes, a patient must take insulin shots. In Type II diabetes, a
patient may may not necessarily need insulin and can sometimes control blood
sugar levels with exercise, diet and other medications.
A condition called hyperinsulinism (HI) is caused by too much insulin and
leads to hypoglycemia (low blood sugar). The inherited form, called congenital
HI, causes severe hypoglycemia in infancy. Sometimes it can be treated with
medication but often requires surgical removal of part or all of the pancreas.
An insulin-secreting tumor of the pancreas, or insulinoma, is a less common
cause of hypoglycemia. Symptoms of low blood sugar include anxiety,
sweating, increased heart rate, weakness, hunger, and light-headedness. Low
blood sugar stimulates release of epinephrine, glucagon and growth hormone,
which help to return the blood sugar to normal.
5-26 exocrine glands
Typical exocrine glands include sweat glands, salivary glands, mammary
glands, stomach, liver, pancreas. (Example of an endocrine gland is the
adrenal gland, which is found on top of the kidneys and secretes the hormone
adrenaline, among others).
Structure
Exocrine glands contain a glandular portion and a duct portion, the structures
of which can be used to classify the gland.


The duct portion may be branched (called compound) or unbranched
(called simple).
The glandular portion may be tubular, acinar, or may be a mix of the two
(called tubuloacinar). If the glandular portion branches, then the gland is
called a branched gland.
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Method of secretion
Exocrine glands are named apocrine gland, holocrine gland, or merocrine
gland based on how their product is secreted.



Apocrine glands - a portion of the plasma membrane buds off the cell,
containing the secretion,an example is fat droplet secretion by
mammary gland.
Holocrine glands - the entire cell disintegrates to secrete its
substance,an example is sebaceous glands for skin and nose.
Merocrine glands - cells secrete their substances by exocytosis an
example is pancreatic acinar cells.
Product secreted



Serous cells secrete proteins, often enzymes. Examples include chief
cells and Paneth cells
Mucous cells secrete mucus. Examples include Brunner's glands,
esophageal glands, and pyloric glands
Mixed glands secrete both protein and mucus. Examples include the
salivary glands, although parotid gland is predominantly serous, the
sublingual gland is predominantly mucous and the submandibular
gland is both serous and mucous
Test No. 1
name the two divisions of adrenal glands and describe the effects of
hormones from each
81
Unit twenty seven
1-27 muscular system
Over 600 skeletal muscles function for body movement through contraction
and relaxation of voluntary, striated muscle fibers. These muscles are attached
to bones, and are typically under conscious control for locomotion, facial
expressions, posture, and other body movements. Muscles account for
approximately 40 percent of body weight. The metabolism that occurs in this
large mass-produces heat essential for the maintenance of body temperature.
2-27 Types of muscles
There are three types of muscles
1. skeletal (or voluntary/striated) muscle, the most abundant tissue in the
human body, producing movement. Each skeletal-muscle fiber is roughly
cylindrical, contains many nuclei, and is crossed by alternating light and
dark bands called striations. Fibers bind together, via connective tissue,
into bundles; and these bundles, in turn, bind together to form muscles.
Thus, skeletal muscles are composite structures composed of many
muscle fibers, nerves, blood vessels, and connective tissue. Skeletal
muscles are controlled by the somatic nervous system (SNS).
2. smooth (or visceral) muscle, forming the muscle layers in the walls of the
digestive tract, bladder, various ducts, arteries and veins, and other
internal organs. Smooth- muscle cells are elongated and thin, not striated,
have only one nucleus, and interlace to form sheets rather than bundles
of muscles. Smooth muscle is controlled by the autonomic nervous
system (ANS).
3. cardiac (or heart) muscle, a cross between the smooth and striated
muscles, comprising the heart tissue. Like smooth muscle, it is
innervated by the autonomic nervous system (ANS).
Test no. 1
List the types of muscles
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Unit twenty eight
1-28 Musculoskeletal System
The musculoskeletal system consists of the skeletal system -- bones and joints
(union of two or more bones) -- and the skeletal muscle system (voluntary or
striated muscles). These two systems work together to provide basic functions
that are essential to life, including:






Protection: protects the brain and internal organs
Support: maintains upright posture
Blood cell formation: hematopoiesis
Mineral homeostasis
Storage: stores fat and minerals.
Leverage: A lever is a simple machine that magnifies speed of
movement or force. The levers are mainly the long bones of the body
and the axes are the joints where the bones meet.
2-28 Tissues
There are 5 basic tissues comprising the musculoskeletal system:
1. bones,
2. ligaments (attaching bone to bone)
3. cartilage (protective gel-like subtance lining the joints and intervertebral
discs),
4. skeletal muscles, and
5. tendons (attaching muscle to bone).
Each of these contains various combinations of 4 connective tissue building
blocks:

fibroblasts - the "mother" cell, producing the other 3 connective tissue
components.
83



collagen - the principal protein manufactured by the fibroblast.
Organized into various configurations, these long, thin fibers intertwine
to form very strong fibers which do NOT stretch.
elastic fibers - highly elastic fibers, unlike collagen, particularly
abundant in the walls of arteries.
proteoglycans - the "ground substance," or "matrix," in which
fibroblasts, collagen, and elastic fibers reside.
3-28 How We Move
Skeletal muscles, attached to bone by tendons, produce movement by bending
the skeleton at movable joints. The connecting tendon closest to the body or
head is called the proximal attachment: this is termed the origin of the muscle.
The other end, the distal attachment, is called the insertion. During contraction,
the origin remains stationary and the insertion moves.
The force producing the bending is always exerted as a pull by contraction,
thus making the muscle shorter: Muscles cannot actively push. Reversing the
direction in which a joint bends is produced by contracting a different set of
muscles. For example, when one group of muscles contracts, an antagonistic
group stretches, exerting an opposing pull, ready to reverse the direction of
movement.
The contracting unit is the muscle fiber. Muscle fibers consist of two main
protein strands - actin and myosin. Where the strands overlap, the fiber
appears dark. Where they do not overlap, the fiber appears light. These
alternating bands of light and dark give skeletal muscle its characterisitc
striated appearance. The trigger which starts contraction comes from the
motor nerve attached to each muscle fiber at the motor end plate.
Acetylcholine is released at the motor end plate when the electrical impulse
reaches the muscle fiber. As it binds to receptors on the surface of the muscle
cells, it causes the electrical impulse to be transmitted in both directions along
the fiber, activating the actin and myosin strands. The strands slide past each
other to flex, or to shorten, the fiber, thus producing contraction.
84
Unit twenty nine
1-29 hormones
A hormone is a chemical released by a cell in one part of the body, that sends
out messages that affect cells in other parts of the organism. Only a small
amount of hormone is required to alter cell metabolism. It is essentially a
chemical messenger that transports a signal from one cell to another. All
multicellular organisms produce hormones. Cells respond to a hormone when
they express a specific receptor for that hormone. The hormone binds to the
receptor protein, resulting in the activation of a signal transduction mechanism
that ultimately leads to cell type-specific responses.
Endocrine hormone molecules are secreted (released) directly into the
bloodstream, while exocrine hormones (or ectohormones) are secreted directly
into a duct, and from the duct they either flow into the bloodstream or they flow
from cell to cell by diffusion .
2-29 Physiology of hormones
Most cells are capable of producing one or more molecules, which act as
signaling molecules to other cells, altering their growth, function, or
metabolism. The classical hormones produced by cells in the endocrine glands
mentioned so far in this article are cellular products, specialized to serve as
regulators at the overall organism level. However they may also exert their
effects solely within the tissue in which they are produced and originally
released.
The rate of hormone biosynthesis and secretion is often regulated by a
homeostatic negative feedback control mechanism. Such a mechanism
depends on factors that influence the metabolism and excretion of hormones.
Thus, higher hormone concentration alone cannot trigger the negative
feedback mechanism. Negative feedback must be triggered by overproduction
of an "effect" of the hormone.
Hormone secretion can be stimulated and inhibited by:




Other hormones (stimulating- or releasing-hormones)
Plasma concentrations of ions or nutrients, as well as binding globulins
Neurons and mental activity
Environmental changes, e.g., of light or temperature
One special group of hormones is the tropic hormones that stimulate the
hormone production of other endocrine glands. For example, thyroidstimulating hormone (TSH) causes growth and increased activity of another
endocrine gland, the thyroid, which increases output of thyroid hormones.
85
3-29 effect of hormones
Hormones have the following effects on the body:









stimulation or inhibition of growth
mood swings
induction or suppression of apoptosis (programmed cell death)
activation or inhibition of the immune system
regulation of metabolism
preparation of the body for mating, fighting, fleeing, and other activity
preparation of the body for a new phase of life, such as puberty,
parenting, and menopause
control of the reproductive cycle
hunger cravings
A hormone may also regulate the production and release of other hormones.
Hormone signals control the internal environment of the body through
homeostasis.
4-29 Pharmacology
Many hormones and their analogues are used as medication. The most
commonly prescribed hormones are estrogens and progestagens (as methods
of hormonal contraception and as HRT), thyroxine (as levothyroxine, for
hypothyroidism) and steroids (for autoimmune diseases and several
respiratory disorders). Insulin is used by many diabetics. Local preparations
for use in otolaryngology often contain pharmacologic equivalents of
adrenaline, while steroid and vitamin D creams are used extensively in
dermatological practice.
A "pharmacologic dose" of a hormone is a medical usage referring to an
amount of a hormone far greater than naturally occurs in a healthy body. The
effects of pharmacologic doses of hormones may be different from responses
to naturally occurring amounts and may be therapeutically useful. An example
is the ability of pharmacologic doses of glucocorticoid to suppress
inflammation.
Test no. 1
Define hormone and what is the effect of hormones
86
Unit thirty
1-30 regulation of body temperature
The temperature of the body is regulated by neural feedback mechanisms
which operate primarily through the hypothalmus. The hypothalmus contains
not only the control mechanisms, but also the key temperature sensors. Under
control of these mechanisms, sweating begins almost precisely at a skin
temperature of 37°C and increases rapidly as the skin temperature rises above
this value. The heat production of the body under these conditions remains
almost constant as the skin temperature rises. If the skin temperature drops
below 37°C a variety of responses are initiated to conserve the heat in the body
and to increase heat production. These include




Vasoconstriction to decrease the flow of heat to the skin.
Cessation of sweating.
Shivering to increase heat production in the muscles.
Secretion of norepinephrine, epinephrine, and thyroxine to increase heat
production
2-30 body temperature
Body temperature is a measure of the body's ability to generate and get rid of
heat. The body is very good at keeping its temperature within a narrow, safe
range in spite of large variations in temperatures outside the body.
When you are too hot, the blood vessels in your skin expand (dilate) to carry
the excess heat to your skin's surface. You may begin to sweat, and as the
sweat evaporates, it helps cool your body. When you are too cold, your blood
vessels narrow (contract) so that blood flow to your skin is reduced to
conserve body heat. You may start shivering, which is an involuntary, rapid
contraction of the muscles. This extra muscle activity helps generate more
heat. Under normal conditions, this keeps your body temperature within a
narrow, safe range.
3-30 Where is body temperature measured?
Your body temperature can be measured in many locations on your body. The
mouth, ear, t, and rectum are the most commonly used places. Temperature
can also be measured on your forehead.
What are Fahrenheit and Celsius?
Thermometers are calibrated in either degrees Fahrenheit (°F) or degrees
Celsius (°C), depending on the custom of the region. Temperatures in the
United States are often measured in degrees Fahrenheit, but the standard in
most other countries is degrees Celsius.
87
4-30 What is normal body temperature?
Most people think of a "normal" body temperature as an oral temperature of
98.6For 37.2 C . This is an average of normal body temperatures. Your
temperature may actually be 1°F (0.6°C) or more above or below 98.6F. Also,
your normal body temperature changes by as much as 1°F (0.6°C) throughout
the day, depending on how active you are and the time of day. Body
temperature is very sensitive to hormone levels and may be higher or lower
when a woman is ovulating or having her menstrual period.
A rectal or ear (tympanic membrane) temperature reading is 0.5 to 1°F (0.3 to
0.6°C) higher than an oral temperature reading. A temperature taken in the
armpit is 0.5 to 1°F (0.3 to 0.6°C) lower than an oral temperature reading.
5-30 What is a fever?
In most adults, an oral temperature above 100F or a rectal or ear temperature
above 101F is considered a fever. A child has a fever when his or her rectal
temperature is 100.4F or higher.
What can cause a fever?
A fever may occur as a reaction to:




Infection. This is the most common cause of a fever. Infections may
affect the whole body or a specific body part (localized infection).
Medicines, such as antibiotics, narcotics, barbiturates, antihistamines,
and many others. These are called drug fevers. Some medicines, such as
antibiotics, raise the body temperature directly; others interfere with the body's
ability to readjust its temperature when other factors cause the temperature to
rise.
Severe trauma or injury, such as a heart attack, stroke, heat exhaustion
or heatstroke, or burns.
Other medical conditions, such as arthritis, hyperthyroidism, and even
some cancers, such as leukemia, Hodgkin's lymphoma, and liver and lung
cancer.
Test no.1
What is the normal rate of temperature in human
Test no. 2
Define fever and cause of it
88
References:
1- Elatine N.Marteb,R.N. (2006) . Essentials of Human
Anatomy and Physiology( eight edition).
2- Memmler,Ruth Lundeen . (1990). structure and function of
the human body ( fourth edition )
3- Gerard j.Tortora , Nichdas p. Anagnostakos . (1987).
Principles of anatomy and physiology ( fifth edition )
89
Ministry of higher education and scientific research
Foundation of technical education
Learning package in filed
Medical physiology
( practical part )
Presented to the first class students
Of
Institute of medical technology – Baghdad
Department of community health
Designed by
Dr. rawaa adnan faraj
2009 -2010
90
A: Over view
1- Target population :
This learning package had been designed to the first
class students in the Community Health Dept. of the Institute
of Medical Technology –Baghdad.
The students are able to do some clinical and hematological
test for human body
91
Unit one
The microscope
Parts and Specifications
Historians credit the invention of the compound microscope to the Dutch spectacle maker,
Zacharias Janssen, around the year 1590.
The compound microscope uses lenses and light to enlarge the image and is also called an
optical or light microscope (vs./ an electron microscope).
The simplest optical microscope is the magnifying glass and is good to about ten times (10X)
magnification. The compound microscope has two systems of lenses for greater magnification.
92
1. the ocular, or eyepiece lens that one looks into
2. the objective lens, or the lens closest to the object. Low power 10X high power 40X , oil
immersion power 100X
Total Magnification power for 10X= 100X
Total magnification power of 40X = 400X
Total magnification power of 100X = 1000X
Before using a microscope, it is important to know the functions of each part.
Eyepiece Lens: the lens at the top that you look through. They are usually 10X or 15X power.
Tube: Connects the eyepiece to the objective lenses
Arm: Supports the tube and connects it to the base
Base: The bottom of the microscope, used for support
Illuminator: A steady light source (110 volts) used in place of a mirror. If your microscope has a
mirror, it is used to reflect light from an external light source up through the bottom of the stage.
Stage: The flat platform where you place your slides. Stage clips hold the slides in place. If
your microscope has a mechanical stage, you will be able to move the slide around by turning
two knobs. One moves it left and right, the other moves it up and down.
Revolving Nosepiece or Turret: This is the part that holds two or more objective lenses and can
be rotated to easily change power.
Objective Lenses: Usually you will find 3 or 4 objective lenses on a microscope. They almost
always consist of 4X, 10X, 40X and 100X powers. When coupled with a 10X (most common)
eyepiece lens, we get total magnifications of 40X (4X times 10X), 100X , 400X and 1000X. To
have good resolution at 1000X, you will need a relatively sophisticated microscope with an Abbe
condenser. The shortest lens is the lowest power, the longest one is the lens with the greatest
power. Lenses are color coded and if built to DIN standards are interchangeable between
microscopes. The high power objective lenses are retractable (i.e. 40XR). This means that if
they hit a slide, the end of the lens will push in (spring loaded) thereby protecting the lens and
the slide. All quality microscopes have achromatic, parcentered, parfocal lenses.
Rack Stop: This is an adjustment that determines how close the objective lens can get to the
slide. It is set at the factory and keeps students from cranking the high power objective lens
down into the slide and breaking things. You would only need to adjust this if you were using
very thin slides and you weren't able to focus on the specimen at high power. (Tip: If you are
using thin slides and can't focus, rather than adjust the rack stop, place a clear glass slide under
the original slide to raise it a bit higher)
Condenser Lens: The purpose of the condenser lens is to focus the light onto the specimen.
Condenser lenses are most useful at the highest powers (400X and above). Microscopes with in
stage condenser lenses render a sharper image than those with no lens (at 400X). If your
microscope has a maximum power of 400X, you will get the maximum benefit by using a
condenser lenses rated at 0.65 NA or greater. 0.65 NA condenser lenses may be mounted in the
stage and work quite well. A big advantage to a stage mounted lens is that there is one less
focusing item to deal with. If you go to 1000X then you should have a focusable condenser lens
with an N.A. of 1.25 or greater. Most 1000X microscopes use 1.25 Abbe condenser lens
systems. The Abbe condenser lens can be moved up and down. It is set very close to the slide
at 1000X and moved further away at the lower powers.
Diaphragm or Iris: Many microscopes have a rotating disk under the stage. This diaphragm has
different sized holes and is used to vary the intensity and size of the cone of light that is
93
projected upward into the slide. There is no set rule regarding which setting to use for a
particular power. Rather, the setting is a function of the transparency of the specimen, the
degree of contrast you desire and the particular objective lens in use.
How to Focus Your Microscope
The proper way to focus a microscope is to start with the lowest power objective lens first and
while looking from the side, crank the lens down as close to the specimen as possible without
touching it. Now, look through the eyepiece lens and focus upward only until the image is
sharp. If you can't get it in focus, repeat the process again. Once the image is sharp with the
low power lens, you should be able to simply click in the next power lens and do minor
adjustments with the focus knob. If your microscope has a fine focus adjustment, turning it a bit
should be all that's necessary. Continue with subsequent objective lenses and fine focus each
time.
94
Unit two &three
Blood smear
Blood smear
Fig. 1 blood film
A blood film or peripheral blood smear is a microscope slide made from a drop
of blood, that allows the cells to be examined microscopically. Blood films are
usually done to investigate the normal blood cells ( R.B.C, W.B.C, platelets) .
Materials
1- Lancet , ethanol 70% , cotton
2- Slides , spreader slide
3- Drop of blood
4- Methanol
5- Leishman stain
Preparation
Blood films are made by placing a drop of blood on one end of a slide, and using
a spreader slide to disperse the blood over the slide's length. The aim is to get a
region where the cells are spaced far enough apart to be counted and
differentiated.
The slide is left to air dry, after which the blood is fixed to the slide by immersing
it briefly in methanol. The fixative is essential for good staining and presentation
of cellular detail. After fixation, the slide is stained to distinguish the cells from
each other.
o
o
o
Stain:Giemsa stain
Leishman stain
95
Characteristic red blood cell abnormalities are anemia, sickle cell anemia and
spherocytosis.
White blood cells are classified according to their propensity to stain with
particular substances, the shape of the nuclei and the granular inclusions.
Types of white blood cells






Neutrophil granulocytes usually make up close to 80% of the white count.
They have multilobate nuclei and lightly staining granules. They assist in
destruction of foreign particles by the immune system by phagocytosis
and intracellular killing.
Eosinophil granulocytes have granules that stain with eosin and play a
role in allergy and parasitic disease. Eos have a multilobate nucleus.
Basophil granulocytes are only seen occasionally. They are
polymorphonuceated and their granules stain dark with alkaline stains
They are further characterised by the fact that the granules seem to
overlie the nucleus. Basophils are similar if not identical in cell lineage to
mast cells, although no conclusive evidence to this end has been shown.
Mast cells are "tissue basophils" and mediate certain immune reactions to
allergens.
Lymphocytes have very little cytoplasm and a large nucleus (high NC
ratio) and are responsible for antigen-specific immune functions, either
by antibodies (B cell) or by direct cytotoxicity (T cell). The distinction
between B and T cells cannot be made by light microscopy.
Plasma cells are mature B lymphocytes that engage in the production of
one specific antibody. They are characterised by light basophilic staining
and a very eccentric nucleus.
96
Unit four and five
Differential Leukocyte Count
Differential count is useful to identity changes in the distribution of
white cells which may be related to specific types of disorders.
Clinical Significance
Differential count is useful to identity changes in the distribution of
white cells which may be related to specific types of disorders. It also
gives idea regarding the severity of the disease and the degree of
response of the body.
Neutrophilia
Increase in the percentage of neutrophils is called neutrophilia. All the
physiological causes that produce leukocytosis give rise to
neutrophilia.The commonest pathological cause is pyogenic bacterial
infection. Decrease in neutrophils (Neutropenia) is ob served in
infections such as bacterial (typhoid) viral (measles influenza etc.) and
in other conditions such as anemias (aplastic, megaloblastic, iron
deficiency) and in suppression of bone marrow by various drugs and
radiation.
Lymphocytosis
It may be relative or absolute.
 Relative lymphocytosis: In this condition the actual number of
lymphocytes is unchanged but due to decrease in neutrophils
mainly the differential count shows an increase in lymphocytes.
 Absolute lymphocytosis It is observed in
1. Children
2. Certain infections such as mumps, cough. measles,
influenza, syphilis, tuberculosis, typhoid and other chronic
infections
3. Infectious mononucleosis
4. Chronic lymphatic leukemia
5.
Lymphopenia
It is observed in acute stages of infections and in excess irradiation.
Eosinophilia
It is observed in asthma, hypersensitivity reactions, parasitic
infestations and in chronic inflammatory diseases
97
Monocytosis
It is observed in tuberculosis, malaria, subacute bacterial endocarditis
typhoid and in Kala azar.
Basophilia
It is usually observed in chronic myeloid leukemia.
Normal values: (Male or Female)





Neutrophils : 40-75% (mean: 57%)
a) Segmented
: 2-6% (mean 3%)
b) band forms
: 50-70% (mean: 54%)
Eosinophils : 1-4% (mean 2%)
Basophils : 0-1 %
Lymphocytes
: 20-45 % (mean: 37%)
Monocytes : 2 8% (mean 6%)
Specimen
The blood smears should be preferably prepared immediately after skin
puncture or venipuncture before mixing with anticoagulant. If EDTA
blood is used the smears should be prepared within 1 to 2 hours after
blood drawing.Other anticoagulants do not give satisfactory results.The
blood smears should be immediately fixed in methanol.
Requirements
1) Microscope slides and a glass spreader
2) Cedar wood oil (Immersion oil)
3) lancet , cotton ethanol 70%, droop of blood
4) Reagents
A. leshiman stain:
It is prepared by dissolving 0.15 g of powdered stain in 100 ml of
(acetone free) methyl alcohol

Store in an amber colored bottle at room temperature (25°C ± 5°C).
The stain improves on standing for about a week
B. Buffer (pH: 7.0): It is prepared as follows:
· Sodium dihydrogen phosphate (NaH2PO4.2H2O)
: 3.76 g
· Potassium dihydrogen phosphate (KH2PO4) : 2.10 g
· Distilled water to 1000 ml. Keep at room temperature (25°C ±5°C).
98
Principle
The polychromic staining solutions (Wright, Leishman Giemsa) contain
methylene blue and eosin. These basic and acidic dyes induce multiple
colors when applied to cells. Methanol acts as fixative and also as a
solvent. The fixative does not allow any further change in the cells and
makes them adhere to the glass slide. The basic component of white
cells (i.e. cytoplasm) is stained by acidic dye and they are described as
eosinophilic or acidophilic. The acidic components (e.g. nucleus with
nucleic acid) take blue to purple shades by the basic dye and they are
called basophilic.The neutral components of the cell are stained by both
the dyes.
Procedure
A thin smear is prepared by spreading a small drop of blood evenly on a
slide.
Making the film
1. Take a clean dry (grease free) slide
2. Transfer a small drop of blood near the edge of the slide.
3. Place the spreader slide at an angle of 30°. Pull back the spreader
until it touches the drop of blood. Let the blood run along the
edge of the spreader
4. Push the spreader forward to the end of the slide with a smooth
movement.
5. Dry the blood smear at room temperature. Adequate drying is
essential to pre serve the quality of the film.
Precautions
1. Dirty slides do not give an even smear
2. Use an appropriate size of blood drop
3. After putting the drop on the slide, make the smear immediately for
even distribution of white blood cells on the slide.
4. The thickness of the smear depends on the angle of the spreader.
If the angle is less than 300 a thinner smear is obtained and if the
angle is more than 300 a thicker smear is obtained.
5. The film must be smooth at the end. There should be no lines
extending across or down through the film and it should not
contain holes.
99
Identification marking
By using a lead pencil or a ball pen, write the identification number on
the slide.
Fixing the Smear
The slide should be stained after making the smear. Methanol present in
the stain fixes the smear. If the staining is to be done later, the blood
smear must be fixed with methanol for 2 to 3 minutes to prevent
distortion of cells.
Staining the Film
1. Cover the smear with the staining solution by adding 10-15 drops
on the smear. Wait exactly for one minute.
2. Add equal number of the drops of buffer solution. Mix the reaction
mixture adequately by blowing on it through a pipette. Wait for 10
minutes.
3. Wash the smear by using tap water (tap water is preferred because
sometimes if distilled water is not stored properly it becomes
slightly acidic and gives unsatisfactory results).
4. Stand the slide in a draining rack or on the laboratory counter to
dry.
Precautions
1. Avoid formation of deposits of stain. They appear on the film as
masses of little black spots. In that case rinse the slide twice with
methanol. Dry and restain using filtered stain
2. Poor staining makes the film blue pink or too dark
3. Use neutral water Acidic water produces red staining effects and
alkaline one gives blue effects. If the film is too blue, rinse it twice
in 1% boric acid in 95% ethanol and examine under the micro
scope after drying.
Examination of Film
1. First examine the stained smear under the low power. In an ideal
smear three zones will appear (i) Thick area (head) (ii) body and (iii) thin
end of the smear (tail).
2. Choose the portion slightly before, the tail—end where the red cells
are, beginning to overlap.
3. Place a drop of immersion oil on the smear. Switch to the oil
immersion objective and increase the light by opening the iris
diaphragm.
4. Examine the film by moving from one field to the next systematically.
Record the type of leukocytes seen in each field.
100
5. Count at least a total of 100 leukocytes. Counting 500 leukocytes
gives high degree of accuracy.
Additional Information
Following staining solutions are also used for the staining of blood
films:
Giemsa stain
a) 0.3 g of Giemsa staining powder is dissolved in glycerol and
kept at 56-60°C (in a water bath) for 2 hours.
b) 25 ml of acetone free methyl alcohol is added and the prepared
staining solution is kept at room temperature for one week.
c) After filtering it is stored in an amber colored bottle at room
temperature.
d) Before use it is necessary to dilute this staining solution 1:10 in
the buffer solution of pH 7.0.
101
Unit sex , seven and eight
Blood Cell Counts : Red blood cell ,white blood cells , platelets
The cells most often counted by this technique are red cells, white cells,
platelets.
Introduction
The technique of counting of the blood cells is known as
hemocytometry. This involves manual counting of the cells with the help
of a microscope after diluting blood in respective diluting fluids.
The cells most often counted by this technique are red cells, white cells,
platelets.
The hemocytometer technique, however, can not differentiate the
various types of the individual cells.
Requirements
1) Microscope , blood , cotton, lancet , ethanol %
2) RBC Pipette




This pipette has a large bulb, which contains a red glass bead.
It has three marks 0.5, 1.0 and 101.
Blood is drawn to 0.5 mark and then diluting fluid is drawn up to
the mark 101.
The dilution of blood is 1:200.
3) WBC Pipette




It is smaller than the red cell pipette and its bulb contains a white
glass bead.
It has three marks 0.5, 1.0 and 11.
The blood is drawn up to 0.5 mark and then diluting fluid is drawn
up to 11 mark.
The dilution of blood is 1: 20.
102
4) The Counting Chamber







The chamber most commonly used is the improved Neubauer
chamber which has an area of 9 sq. mm and a depth of 0.1 mm.
The two stages are separated from two ridges, one on either side,
by a gutter.
The surface of the two ridges is 1/10 mm above the stage.
The 9 sq. mm area of the counting chamber is divided into 9
squares. The four corner squares measure 1 sq. mm area.
The squares at the corner are divided into 16 small squares each
and are used for counting white cells.
The central square is divided into 25 squares and each of these
square is further divided into 16 small squares, each square
measures 1/400 sq. mm in area.
Five of the medium squares (or 80 small squares) are used in
counting red cells.
5) Cover Slips

A special type of cover slip is used with a very smooth and even
surface. These are available in two sizes (a) 16 x 22 mm and (b) 22
x 23 mm. The thickness of the cover slips may be 0.3 mm, 0.4 mm
or 0.5 mm.
Note: Following precautions are taken while using the counting chamber
and the pipettes:
1. The counting chamber should be clean and dry.
2. After pipetting blood up to the mark, wipe the out side of
the pipette by using cotton or gauze.
3. Diluting fluid is drawn up to the mark and care is taken not
to allow air bubbles to enter.
4. The pipette is rotated rapidly between the fingers to allow
the fluid to mix well. The fluid should not be allowed to run
out of the pipette. This is possible if the pipette is kept
perfectly horizontal during mixing.
5. Initial few drops should be discarded from the pipette.
6. The filling of the chamber should be done in one
application of the tip of the pipette. Fluid should not flow in
to the surrounding moat. The fluid charged chamber should
be placed on a film platform (or bench), away from direct
sun light or other source of heat. The cover glass should be
of a special thick glass and it should be perfectly flat.
7. Air bubbles should not be present under the cover slip.
8. The diluting fluid should not overrun the cover slip.
9. The cells are allowed to settle for 2 to 3 minutes so that
they are seen in the same plane of focus.
10. Longer waiting leads to drying of the fluid and disturbs the
cells.
103
11. Before the counting the condenser and mirror of the
microscope should be properly adjusted.
12. The distribution of the cells should be observed carefully. If
it is not proper the preparation should be discarded and the
blood cell dilution procedure should be repeated.
13. First the low power is used to focus the ruling on the
chamber. The counting is done under the high dry power
(40 X objective).
14. While counting, the cells contained within the square and
those cells touching or lying on the lines of any two
adjacent sides (top and right, or bottom and left) are
included in the count.
15. The error of pipettes and dilution can be decreased by
using larger volumes of blood and diluting fluid.
Note: The preparation must be discarded and the filling procedure
should be repeated by using another clean and dry chamber if1. Chamber area is incompletely filled
2. Fluid overflows into moat
3. Air bubbles are seen anywhere in chamber area
Normal value of white blood cells
1.
2.
3.
4.
5.
Age 6 Months to 2 years: 6.0 to 17.5 (Mean 11.0)
Age 4 Years: 5.5 to 15.5 (Mean 9.1)
Age 6 Years: 5.0 to 14.5 (Mean 8.5)
Age 8 to 16 Years: 4.5 to 13.5 (Mean 8.1)
Age over 21 Years: 4.5 to 11.0 (Mean 7.4)
Normal value of red blood cells
2. Findings: Normal Values (in 10^6/ul or 10^12/L) per age
1. Age <1 month: 3.6 to 6.6
2. Age 1-6 months: 2.7 to 5.4
3. Age 0.5 - 6 years: 3.7 to 5.3
4. Age 6-12 years: 4.0 to 5.2
5. Female
1. Age 12-18 years: 4.1 to 5.1
2. Age >18 years: 3.8 to 5.2
6. Male
1. Age 12-18 years: 4.5 to 5.3
2. Age >18 years: 4.4 to 5.9
104
105
Unit nine and ten
Determination of Hemoglobin.
Clinical Significance
A decrease in hemoglobin below normal range is an indication of
anemia. An increase in hemoglobin concentration occurs in
hemoconcentration due to loss of body fluid in severe diarrhea and
vomiting. High values are also observed in congenital heart disease
(due to reduced oxygen supply in emphysema and also in polycythemia.
Hemoglobin concentration drops during pregnancy due to hemodilution.
Normal values
Men
Women
Children(up to 1 year)
Children (10-12 years)
Infants (full term cord blood)
Hb, g/dl
13-18
12-16.5
11.0-13.0
11.5-14.5
13.5-19.5
Method
Sahli (acid hematin) method
Principle
When blood is added to 0.1 N hydrochloric acid, hemoglobin is
converted to brown colored acid hematin. The resulting color after
dilution is coin- pared with standard brown glass reference blocks of a
Sahli hemoglobinometer
Specimen
Capillary blood or thoroughly mixed anticoagulated (EDTA or double
oxalated) venous blood. The specimen need not be a fasting sample.
Requirements
1) Sahli hemoglobinometer: It consists of
a. A standard brown glass mounted on a comparator
b. A graduated tube
c. Hb-pipette (0.02 ml)
Refer to the colored plates.
Note: The graduations on currently used Hellige tube gives 14.5 g as
100%. These are square tubes with graduations in percent on one side
and grams per 100 ml (dl) on the other side.
106
2) 0. IN hydrochloric acid
3) Distilled water
4) Pasteur pipettes
5) lancet ,ethanol 70%,cotton ,blood
Procedure
1. By using a Pasteur pipette add 0.1 N hydrochloric acid in the tube
up to the lowest mark (20%mark).
2. Draw blood up to 20 µl mark in the Hb-pipette. Adjust the blood
column, carefully without bubbles. Wipe excess of the blood on
the sides of the pipette by using a dry piece of cotton.
3. Transfer blood to the acid in the graduated tube rinse the pipette
well mix the reaction mixture and allow the tube to stand for at
least 10 minutes
4. Dilute the solution with distilled water by adding few drops at a
time carefully and by mixing the reaction mixture, until the color
matches with the glass plate in the comparator
5. The matching should be done only against natural light. The level
of the fluid is noted at its lower meniscus and the reading
corresponding to this level on the scale is recorded in g/dl.
Additional Information
1. Methemoglobin carboxyhemoglobin and sulfhemoglobin are not
converted to acid hematin by 0.1 N hydrochloric acid.
2. This method is useful for places where a photometer is not
available.
3. It can give an error up to 1 g/dl
Precaution
1. Immediately after use rinse the Hb pipette by using tap water in a
beaker. This prevents blocking of the pipette.
107
Unit eleven and twelve
Determination of PCV by Micro Hematocrit Method
Determination of PCV by Micro Hematocrit Method
In the case of difficulty in drawing sufficient amount of blood, microhematocrit method is used. It is useful particularly in pediatric patients.
The method is ideal for skin puncture.
Specimens
1. EDTA or oxalated specimen (use plain capillary tubes). Or
2. Capillary blood (use heparinized capillaries).
Note: It is necessary to determine PCV within 6 hours - after the blood
collection.
Principle
Blood is centrifuged in a sealed capillary tube and PCV is determined by
a special hematocrit reader.
Requirements
1) Hematocrit centrifuge
It runs at high speed and produces RCF of 12,000 x g and runs at a
speed of about 15,000 RPM. It contains a head to hold the capillary
tubes.
2) Hematocrit reader
This is supplied by the manufacturer.
3) Capillary hematocrit tubes
These are 75 mm in length with approximately 1 mm diameter.
4) Soft wax or modelling clay
This is used to seal the end of the hematocrit tube
5) lancet , ethanol 70% ,cotton , blood
Procedure
1. Draw the blood into an appropriate capillary tube. Fill in the tube
to about ¾ length
2. Seal both the ends of the tube with soft wax or modelling clay. It
is plugged to a depth of about 1 centimeter
3. Write identification number on the tube by using a marking pencil.
4. Place the tube with another similar tube in the radial grooves of
the centrifuge head exactly opposite to each other (empty
capillary tube also can be used).
5. Close the centrifuge cover and centrifuge the tubes at high speed
(about 15,000 RPM) for 5 minutes.
108
6. Remove the capillary tube. It will show three layers — (a) Clear
plasma at the top, (b) Whitish buffy coat at the middle and (c)
column of red cells at the bottom.
7. Hold the tube against the hematocrit scale so that the bottom of
the column of red cells is aligned with the horizontal zero line
(exclude the height of clay).
8. Move the tube across the scale until the line marked 1.0 passes
through the top of the plasma column.
9. The line that passes through the top or the column of red cells
gives the value of PCV (hematocrit).
10.
Source of Error
1. Hemolyzed specimen will yield false low values.
2. Inadequate mixing of blood and incompleteness of packing may
lead to erroneous results.
3.
Disadvantages
It requires a special centrifuge and disposable capillary tubes.
Additional observations
Note any abnormal findings such as
1) the color of plasma (yellow for jaundice and reddish for hemolysis)
2) Increased huffy coat for increased white blood cells.
109
P.C.V method
110
Unit thirteen and fourteen
Erythrocyte Sedimentation Rate (ESR)
The rate at which the red cells fall is known as the erythrocyte
sedimentation rate.
(1) ESR is greater in women than in men and it is related to the
difference in PCV.
(2) During pregnancy ESR gradually increases after 3rd month and
returns to normal in about 3 to 4 weeks after delivery.
(3) ESR is low in infants and gradually increases up to puberty. It
decreases until old age and it again increases.
(4) The Laboratory factors which influence ESR are as follows:
a) Time: The test should be performed as early as possible
after the collection of fasting specimen. There is
progressive decrease in sedimentation in first four hours
and after that there is a rapid decrease in sedimentation.
b) The length of the ESR tube: ESR is greater with longer tubes
(Westergren’s tube) than with shorter tube (Wintrobe’s
tube). To ensure reliable results the column of blood should
be as high as possible. The internal diameter of the tube
should be more than 2.5 mm. The tubes should be kept in
vertical position. Deviation of the tubes from the vertical
position increases the ESR.
c) Temperature: The red cell sedimentation is increased at
higher temperature.
Clinical Significance
1. ESR is increased in all conditions where there is tissue
breakdown or where there is entry of foreign proteins in the
blood, except for localized mild infections. The determination is
useful to check the progress of the disease. If the patient is
improving the ESR tends to fall. If the patient’s condition is
getting worse the ESR tends to rise.
The changes of ESR are, however, not diagnostic of any specific
disease.
111
Determination of Erythrocyte Sedimentation Rate
Method
Westergren’s method.
The following figure is the Determination of ESR by Westergren’s
Method
Normal range


Male 0-15 mm after 1st hour
Female 0-20 mm after 1st hour
Specimens
1. Small tube (100 * 10 mm) with 2.5 ml mark is used for blood
collection. (If the tube is not graduated, pipette out 2.5 ml of 3.8%
sodium citrate in the tube and after marking the level of fluid,
remove 2.0 ml of the solution leaving 0.5 ml of the anticoagulant
in the tube).
2. The tubes with 0.5 ml of 3.8% odium citrate should be kept ready
before blood collection.
3. Patient should be fasting for 12 to 16 hours. Collect blood by
venipuncture and add in the tube up to the mark and mix
carefully.
Note: Fasting EDTA blood also can be used. In that case add 2.0 ml of
blood to 0.5 ml, 3.8% sodium citrate.
112
Requirement
1.
2.
3.
4.
Westergren’s ESR lube
Stand for holding the tube
Timer or watch
lancet ,cotton, ethanol 70%, blood
Procedure
1. Fill the Westergren’s tube exactly up to zero mark by means of a
rubber bulb (avoid air bubbles).
2. Place the tube upright in the stand. It should fit evenly into the
groove of the stand.
3. Note the time. Allow the tube to stand for exactly one hour.
4. Exactly after one hour, note the level to which the red cell column
has fallen.
5. Report the result in terms of mm/after 1st hour.
Precaution
Wash the tubes as early as possible, under running tap water. Rinse in
deionized water and dry in the incubator between 40oC-50oC.
113
Unit fifteen and sixteen
Blood groups test
Requirement





Lancets
Plastic pipette
Alcohol swab
Blood
Blood group test ( anti A, anti B , anti D )
Precautions

Perform test at room temperature
1. Wash your hands before carrying out the test and again after
carrying out the test.
2. Wipe a fingertip with the alcohol impregnated tissue provided and
allow it to dry.
3. Place the lancet against the end of the finger and press the green
body against your finger to release the needle.
4. Massage the finger from the bottom to the top to encourage
bloodflow. Press the blood towards fingertip. Repeat pressing
until a drop with a 3 to 4 mm (1/8 inch) diameter is seen.
114
5. Transfer the blood to an glass slide, approached from beneath the
finger. Don’t smear the blood over the skin.
6. Place the anti A with the drop of blood into the first circle. and
blood mixture until the coloured dry material has dissolved.
7. Repeat this procedure for the other 3 circles, making sure you use
a new stick for each circle.
8. As soon as you have finished tilting read and record the results
immediately. See the table below for how the results are
interpreted.
115
Unit seventeen and eighteen
Blood pressure
A sphygmomanometer, a device used for measuring arterial pressure.
Blood pressure (BP) is the pressure (force per unit area) exerted by
circulating blood on the walls of blood vessels, and constitutes one of
the principal vital signs. The pressure of the circulating blood decreases
as it moves away from the heart through arteries and capillaries, and
toward the heart through veins. When unqualified, the term blood
pressure usually refers to brachial arterial pressure: that is, in the major
blood vessel of the upper left or right arm that takes blood away from
the heart. Blood pressure may, however, sometimes be measured at
other sites in the body, for instance at the ankle. The ratio of the blood
pressure measured in the main artery at the ankle to the brachial blood
pressure gives the Ankle Brachial Pressure Index (ABPI).
Measurement
Arterial pressure is most commonly measured via a
sphygmomanometer, which historically used the height of a column of
mercury to reflect the circulating pressure. Today blood pressure values
are still reported in millimetres of mercury (mmHg), though aneroid and
electronic devices do not use mercury.
For each heartbeat, blood pressure varies between systolic and diastolic
pressures. Systolic pressure is peak pressure in the arteries, which
occurs near the beginning of the cardiac cycle when the ventricles are
contracting. Diastolic pressure is minimum pressure in the arteries,
which occurs near the end of the cardiac cycle when the ventricles are
filled with blood. An example of normal measured values for a resting,
healthy adult human is 115 mmHg systolic and 75 mmHg diastolic
(written as 115/75 mmHg, and spoken (in the US) as "one fifteen over
seventy-five"). Pulse pressure is the difference between systolic and
diastolic pressures.
116
Systolic and diastolic arterial blood pressures are not static but undergo
natural variations from one heartbeat to another and throughout the day
(in a circadian rhythm). They also change in response to stress,
nutritional factors, drugs, disease, exercise, and momentarily from
standing up. Sometimes the variations are large. Hypertension refers to
arterial pressure being abnormally high, as opposed to hypotension,
when it is abnormally low. Along with body temperature, blood pressure
measurements are the most commonly measured physiological
parameters.
Arterial pressures can be measured invasively (by penetrating the skin
and measuring inside the blood vessels) or non-invasively. The former
is usually restricted to a hospital setting.
Units
The predominantly used unit for blood pressure measurement is mmHg
(millimeter of mercury). For example, normal pressure can be stated as
120 over 80.
Palpation methods
A minimum systolic value can be roughly estimated without any
equipment by palpation, most often used in emergency situations.
Palpation of a radial pulse indicates a minimum blood pressure of
80 mmHg, a femoral pulse indicates at least 70 mmHg, and a carotid
pulse indicates a minimum of 60 mmHg. However, one study indicated
that this method was not accurate enough and often overestimated
patients' systolic blood pressure.[1] A more accurate value of systolic
blood pressure can be obtained with a sphygmomanometer and
palpating for when a radial pulse returns.[2] The diastolic blood pressure
can not be estimated by this method.[3]
Auscultatory methods
Auscultatory method aneroid sphygmomanometer with stethoscope
117
Mercury manometer
The auscultatory method uses a stethoscope and a
sphygmomanometer. This comprises an inflatable (Riva-Rocci) cuff
placed around the upper arm at roughly the same vertical height as the
heart, attached to a mercury or aneroid manometer. The mercury
manometer, considered to be the gold standard for arterial pressure
measurement[citation needed], measures the height of a column of mercury,
giving an absolute result without need for calibration, and consequently
not subject to the errors and drift of calibration which affect other
methods. The use of mercury manometers is often required in clinical
trials and for the clinical measurement of hypertension in high risk
patients, such as pregnant women.
A cuff of appropriate size is fitted smoothly and snugly,then inflated
manually by repeatedly squeezing a rubber bulb until the artery is
completely occluded. Listening with the stethoscope to the brachial
artery at the elbow, the examiner slowly releases the pressure in the
cuff. When blood just starts to flow in the artery, the turbulent flow
creates a "whooshing" or pounding (first Korotkoff sound). The
pressure at which this sound is first heard is the systolic blood
pressure. The cuff pressure is further released until no sound can be
heard (fifth Korotkoff sound), at the diastolic arterial pressure.
Sometimes, the pressure is palpated (felt by hand) to get an estimate
before auscultation.
118
Classification
The following classification of blood pressure applies to adults aged 18
and older. It is based on the average of seated blood pressure readings
that were properly measured during 2 or more office visits.
Classification of blood pressure for adults
Category
systolic, mmHg
Hypotension
< 90
or < 60
Normal
90 – 119
and 60 – 79
Prehypertension
120 – 139
or 80 – 89
Stage 1 Hypertension
140 – 159
or 90 – 99
Stage 2 Hypertension
≥ 160
or ≥ 100
119
diastolic, mmHg
Unit nineteen and twenty
Temperature measurement
A medical/clinical thermometer showing the temperature of 38.7 °C
Temperature measurement using modern scientific thermometers and
temperature scales goes back at least as far as the early 18th century,
when Gabriel Fahrenheit adapted a thermometer (switching to mercury)
and a scale both developed by Ole Christensen Røemer. Fahrenheit's
scale is still in use, alongside the Celsius scale and the Kelvin scale.
A medical/clinical thermometer showing the temperature of 38.7 °C
Medical thermometers are used for measuring human body temperature,
with the tip of the thermometer being inserted either into the mouth (oral
temperature), under the armpit (axillary temperature), or into the rectum
via the anus (rectal temperature).
Classification, by technology
Electronic clinical thermometers
The traditional mercury-filled medical thermometer works in the same
way as a meteorological maximum thermometer. The thermometer
consists of a mercury-filled bulb attached to a small tube. There is a
constriction in the neck close to the bulb. As the temperature rises, the
force of the expansion pushes the mercury up the tube through the
constriction. When the temperature falls, the column of mercury breaks
at the constriction and cannot return to the bulb, thus remaining
stationary in the tube. To reset the thermometer, it must be swung
sharply.
120
When it is designed for use in humans, the typical range of this kind of
thermometer is from about 35°C to 42°C or 89.6°F to 109.4°F. The
temperature is obtained by reading the scale inscribed on the side of the
thermometer.
Close-up of a maximum thermometer. The break in the column of
mercury is visible.
In the 1990s, mercury-based thermometers were found too risky to
handle; the vigorous swinging needed to "reset" a mercury maximum
thermometer makes it easy to accidentally break it, and spill the
poisonous mercury. Mercury thermometers have largely been replaced
with electronic digital thermometers, or, more rarely, thermometers
based on liquids other than mercury (such as heat-sensitive liquid
crystals). Other modern options include digital Infrared contact or noncontact thermometers, which are also called scanner thermometers.
Most medical thermometers may be used to take oral, axillary, vaginal,
or rectal temperatures.
To eliminate the risk of patient cross-infection, disposable single-use
clinical thermometers and probe covers are employed in clinics and
hospitals.
Classification, by location
Oral
Oral temperature may only be taken from a patient who is capable of
holding the thermometer in their mouth correctly and securely, which
generally excludes small children or people who are overcome by
coughing, weakness, or vomiting. (This is less of a problem with fastreacting digital thermometers, but was certainly an issue with mercury
thermometers, which took several minutes to register a temperature.)
Another counter-indication is if the patient has drunk a hot or cold liquid
beforehand, in which case one has to wait or use another method.
121
Rectal
Rectal thermometry
Rectal temperature-taking, especially if performed by a person other
than the patient, should be facilitated with the use of lubricant (such as
petroleum jelly (now discouraged) or a water-based personal lubricant).
Although rectal temperature is the most accurate, this method may be
considered embarrassing in some countries or cultures, especially if
used on patients older than young children; also, if not taken the correct
way, a rectal temperature-taking can be uncomfortable and in some
cases painful for the patient. Rectal temperature-taking is considered
the method of choice for infants for the general public and the rectal
route is also desirable in infants from a nursing point of view.[3]
122
Unit twenty one and twenty two
Electro cardio graphic (E.C.G)
Electrocardiography is a commonly used, noninvasive procedure for recording electrical
changes in the heart. The record, which is called an electrocardiogram (ECG or EKG), shows the
series of waves that relate to the electrical impulses that occur during each beat of the heart. The
results are printed on paper and/or displayed on a monitor to provide a visual representation of
heart function. The waves in a normal record are named P, Q, R, S, and T, and follow in
alphabetical order. The number of waves may vary, and other waves may be present.
Purpose
Electrocardiography is a starting point for detecting many cardiac problems, including angina
pectoris, stable angina, ischemic heart disease, arrhythmias (irregular heartbeat), tachycardia
(fast heartbeat), bradycardia (slow heartbeat), myocardial infarction (heart attack), and certain
congenital heart conditions. It is used routinely in physical examinations and for monitoring a
patient's condition during and after surgery, as well as in the intensive care setting. It is the
basic measurement used in exercise tolerance tests (i.e., stress tests) and is also used to
evaluate symptoms such as chest pain, shortness of breath, and palpitations.
Description
The patient disrobes from the waist up, and electrodes (tiny wires in adhesive pads) are applied
to specific sites on the arms, legs, and chest. When attached, these electrodes are called leads;
three to 12 leads may be employed for the procedure.
Muscle movement may interfere with the recording, which lasts for several beats of the heart. In
cases where rhythm disturbances are suspected to be infrequent, the patient may wear a small
Holter monitor in order to record continuously over a 24-hour period. This is known as
ambulatory monitoring.
123
Special training is required for interpretation of the electrocardiogram. To summarize in the
simplest manner the features used in interpretations, the P wave of the electrocardiogram is
associated with the contraction of the atria—the two chambers of the heart that receive blood
from the veins. The QRS series of waves, or QRS complex, is associated with ventricular
contraction, with the T wave coming after the contraction. The ventricles are the two chambers
of the heart that receive blood from the atria and that send the blood into the arteries. Finally, the
P-Q or P-R interval gives a value for the time taken for the electrical impulse to travel from the
atria to the ventricle (normally less than 0.2 seconds).
Diagnosis/Preparation
Patients are asked not to eat for several hours before a stress test . Before the leads are
attached, the skin is cleaned to obtain good electrical contact at the electrode positions and,
occasionally, shaving the chest may be necessary.
Heart problems are diagnosed by the pattern of electrical waves produced during the EKG, and
an abnormal rhythm can be called dysrhythmia. The cause of dysrhythmia is ectopic beats.
Ectopic beats are premature heartbeats that arise from a site other than the sinus node—
commonly from the atria, atrioventricular node, or the ventricle. When these dysrhythmias are
only occasional, they may produce no symptoms or simply a feeling that the heart is turning
over or "flip-flopping." These occasional dysrhythmias are common in healthy people, but they
also can be an indication of heart disease.
The varied sources of dysrhythmias provide a wide range of alterations in the form of the
electrocardiogram. Ectopic beats display an abnormal QRS complex. This can indicate disease
associated with insufficient blood supply to the heart muscle (myocardial ischemia). Multiple
ectopic sites lead to rapid and uncoordinated contractions of the atria or ventricles. This
condition is known as fibrillation. When the atrial impulse fails to reach the ventricle, a condition
known as heart block results.
Aftercare
To avoid skin irritation from the salty gel used to obtain good electrical contact, the skin should
be thoroughly cleaned after removal of the electrodes.
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Risks
The EKG is a noninvasive procedure that is virtually risk-free for the patient. There is a slight risk
of heart attack for individuals undergoing a stress test EKG, but patients are carefully screened
for their suitability for this test before it is prescribed.
Risk factors for heart disease include obesity, hypertension (high blood pressure), high
triglycerides and total blood cholesterol, low HDL ("good") cholesterol, tobacco smoking, and
increased age. People who have diabetes mellitus (either type 1 or type 2) are also at increased
risk for cardiovascular disease.
Normal results
When the heart is operating normally, each part contracts in a specific order. Contraction of the
muscle is triggered by an electrical impulse. These electrical impulses travel through specialized
cells that form a conduction system. Following this pathway ensures that contractions will occur
in a coordinated manner.
When the presence of all waves is observed in the electrocardiogram, and these waves follow
the order defined alphabetically, the heart is said to show a normal sinus rhythm, and impulses
may be assumed to be following the regular conduction pathway.
In the normal heart, electrical impulses—at a rate of 60–100 times per minute—originate in the
sinus node. The sinus node is located in the first chamber of the heart, known as the right
atrium, where blood reenters the heart after circulating through the body. After traveling down to
the junction between the upper and lower chambers, the signal stimulates the atrioventricular
node. From here, after a delay, it passes by specialized routes through the lower chambers or
ventricles. In many disease states, the passage of the electrical impulse can be interrupted in a
variety of ways, causing the heart to perform less efficiently.
The heart is described as showing arrhythmia or dysrhythmia when time intervals between
waves, or the order or the number of waves do not fit the normal pattern described above. Other
features that may be altered include the direction of wave deflection and wave widths.
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Alternatives
Electrocardiography is the gold standard for detecting heart conditions involving irregularities in
electrical conduction and rhythm. Other tests that may be used in conjunction with an EKG
include an echocardiogram (a sonogram of the heart's pumping action) and a stress test—an
EKG that is done in conjunction with treadmill or other supervised exercise to observe the
heart's function under stress—may also be performed.
Beasley, Brenda. Understanding EKGs: A Practical Approach. 2nd ed. Upper Saddle River, NJ:
Prentice Hall, 2002.
The P wave represents atrial activation; the PR interval is the time from
onset of atrial activation to onset of ventricular activation. The QRS
complex represents ventricular activation; the QRS duration is the
duration of ventricular activation. The ST-T wave represents ventricular
repolarization. The QT interval is the duration of ventricular activation
and recovery. The U wave probably represents "afterdepolarizations" in
the ventricles.
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Unit twenty three and twenty four
Physical examination
Physical examination or clinical examination is the process by which a doctor investigates the
body of a patient for signs of disease. It generally follows the taking of the medical history — an
account of the symptoms as experienced by the patient. Together with the medical history, the
physical examination aids in determining the correct diagnosis and devising the treatment plan.
This data then becomes part of the medical record.
Format and interpretation
Although providers have varying approaches as to the sequence of
body parts, a systematic examination generally starts at the head and
finishes at the extremities.
After the main organ systems have been investigated by inspection,
palpation, percussion and auscultation,
A complete physical examination includes evaluation of general patient
appearance and specific organ systems. It is recorded in the medical
record in a standard layout which facilitates others later reading the
notes. In practice the vital signs of temperature examination, pulse and
blood pressure are usually measured first.
Vital signs
Vital signs
The primary vital signs are:





Temperature recording
Blood pressure
Pulse
Respiratory rate
Pain level assessment
Basic biometrics
Height
Height is the anthropometric longitudinal growth of an individual. A
statiometer is the device used to measure height although often a height
stick is more frequently used for vertical measurement of adults or
children older than 2. The patient is asked to stand barefoot. Height
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declines during the day because of compression of the intervertebral
discs. Children under age 2 are measured lying horizontally.
Weight
Weight is the anthropometric mass of an individual. A scale is used to
measure weight.
Medical professionals generally prefer to use the SI unit of kilograms,
and many medical facilities have ready-reckoner conversion charts
available for professionals to use, when patients describe their weight in
non-SI units. (In the US, pounds and ounces are common,
Body mass index (BMI) or height-weight tables, may be used to compare
the relationship between height and weight, and may suggest conditions
such as obesity or being overweight or underweight.
Structure of the written examination record
Organ systems


Cardiovascular system
o

Blood pressure, pulse rate and rhythm.
Respiratory system Lungs
o 4 parts: observation, auscultation, palpation, percussion
 Observation involves observing the respiratory rate
which should be in a ratio of 1:2




Lung auscultation is listening to the lungs bilaterally
at the anterior chest and posterior chest. Wheezing is
described as a musical sound on expiration or
inspiration. It is the result of narrowed airways.
Rhonchi are bubbly sounds similar to blowing
bubbles through a straw into a sundae. They are
heard on expiration and inspiration. It is the result of
viscous fluid in the airways. Crackles or rales are
similar to rhonchi except they are only heard during
inspiration. It is the result of alveoli popping open
from increased air pressure
For palpation, place both palms or medial aspects of
hands on the posterior lung field. Ask the patient to
count 1-10. The point of this part is to feel for
vibrations and compare between the right/left lung
field. If the pt has a consolidation (maybe caused by
pneumonia), the vibration will be louder at that part of
the lung. This is because sound travels faster
through denser material than air.
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

On percussion, you are testing mainly for pleural
effusion or pneumothorax. The sound will be more
tympanic if there is a pneumothorax because air will
stretch the pleural membranes like a drum. If there is
fluid between the pleural membranes, the percussion
will be dampened and sound muffled.

o
If there is pneumonia, palpation may reveal increased
vibration and dullness on percussion. If there is pleural
effusion, palpation should reveal decreased vibration and
there will be 'stony dullness' on percussion.
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Unit twenty five and twenty sex
Heart sounds
Heart sounds
Front of thorax, showing surface relations of bones, lungs (purple),
pleura (blue), and heart (red outline). Heart valves are labeled with "M",
"T", "A", and "P".
First heart sound: caused by atrioventricular valves - Mitral (M) and
Tricuspid (T).
Second heart sound caused by semilunar valves -- Aortic (A) and
Pulmonary/Pulmonic (P).
The heart sounds are the noises (sound) generated by the beating heart
and the resultant flow of blood through it. This is also called a heartbeat.
In cardiac auscultation, an examiner uses a stethoscope to listen for
these sounds, which provide important information about the condition
of the heart.
In healthy adults, there are two normal heart sounds often described as
a lub and a dub (or dup), that occur in sequence with each heart beat.
These are the first heart sound (S1) and second heart sound (S2),
produced by the closing of the AV valves and semilunar valves
respectively. In addition to these normal sounds, a variety of other
sounds may be present including heart murmurs, adventitious sounds,
and gallop rhythms S3 and S4.
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Heart murmurs are generated by turbulent flow of blood, which may
occur inside or outside the heart. Murmurs may be physiological
(benign) or pathological (abnormal). Abnormal murmurs can be caused
by stenosis restricting the opening of a heart valve, resulting in
turbulence as blood flows through it. Abnormal murmurs may also
occur with valvular insufficiency (or regurgitation), which allows
backflow of blood when the incompetent valve closes with only partial
effectiveness. Different murmurs are audible in different parts of the
cardiac cycle, depending on the cause of the murmur.
Normal heart sounds
Normal heart sounds are associated with heart valves closing, causing
changes in blood flow.
S1
The first heart tone, or S1, forms the "lubb" of "lubb-dub" or "lubb-dup"
and is composed of components M1 and T1. Normally M1 precedes T1
slightly. It is caused by the sudden block of reverse blood flow due to
closure of the atrioventricular valves, i.e. mitral and tricuspid, at the
beginning of ventricular contraction, or systole. When the ventricles
begin to contract, so do the papillary muscles in each ventricle. The
papillary muscles are attached to the tricuspid and mitral valves via
chordae tendineae, which bring the cusps of the valve closed (chordae
tendineae also prevent the valves from blowing into the atria as
ventricular pressure rises due to contraction). The closing of the inlet
valves prevents regurgitation of blood from the ventricles back into the
atria. The S1 sound results from reverberation within the blood
associated with the sudden block of flow reversal by the valves.[1] If T1
occurs more than slightly after M1, then the patient likely has a
dysfunction of conduction of the right side of the heart such as a Right
bundle branch block.
S2
The second heart tone, or S2, forms the "dub" of "lubb-dub" or "lubbdup" and is composed of components A2 and P2. Normally A2 precedes
P2 especially during inspiration when a split of S2 can be heard. It is
caused by the sudden block of reversing blood flow due to closure of
the aortic valve and pulmonary valve at the end of ventricular systole,
i.e. beginning of ventricular diastole. As the left ventricle empties, its
pressure falls below the pressure in the aorta, aortic blood flow quickly
reverses back toward the left ventricle, catching the aortic valve leaflets
and is stopped by aortic (outlet) valve closure. Similarly, as the pressure
in the right ventricle falls below the pressure in the pulmonary artery,
the pulmonary (outlet) valve closes. The S2 sound results from
reverberation within the blood associated with the sudden block of flow
reversal.
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Unit twenty seven
Artificial inspiration
Respiratory failure is a critical concern for a first aider. If the person is not breathing, then
problems such as bleeding, broken bones, burns, scalds, and shock are secondary issues.
Given the amount of time your group will spend in the wilds either hiking or camping, it is
reasonable and prudent to expect all members of your Patrol and Troop to be proficient in
artificial respiration.
There are many different techniques for giving artificial respiration. The most widely taught and
accepted technique goes by a variety of names, such as "mouth to mouth", "rescue breathing",
and "direct". Using this technique, air is expelled from the rescuers lungs directly into the
victim's mouth. Assuming a tight air seal, the air is forced into the victim's lungs, and the
rescuer watches to see the victim's chest rise with each breath. This technique is direct, and the
effectiveness can be visually measured by the rescuer. If the chest of the victim does not rise,
then the mouth and throat should be checked for obstructions before rescue breathing is
continued.
The head, before being tipped back,
showing the tongue obstructing the airway
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To perform rescue breathing perform the following steps:
1. Check the mouth for obstructions, lift the neck and tilt the head
back.
2. Pinch the nostrils and seal the mouth, and exhale directly into the
victim's mouth.
3. Release the nostrils and the seal around the mouth.
4. Watch for the victim's chest to rise by itself.
5. Feel for a pulse on the victim's neck.
6. If the victim's chest does not start to rise on its own, repeat this
process from number 1, until professional help arrives.
Rescue breathing should continue at a normal breathing pace of about 12 times per minute, until
the victim is fully able to breath on his or her own. Even if the victim appears able to breath on
their own, be sure to keep a close watch since relapses are common.
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Unit twenty eight
Respiratory volume
Remember: Capacities are always the summation of volumes.
TIDAL VOLUME (TV): Volume inspired or expired with each
normal breath.
INSPIRATORY RESERVE VOLUME (IRV): Maximum volume that can be
inspired over the inspiration of a tidal volume/normal breath. Used
during exercise/exertion.
EXPIRATRY RESERVE VOLUME (ERV): Maximal volume that can be
expired after the expiration of a tidal volume/normal breath.
RESIDUAL VOLUME (RV): Volume that remains in the lungs after a
maximal expiration. CANNOT be measured by spirometry.
INSPIRATORY CAPACITY ( IC): Volume of maximal inspiration:
IRV + TV
FUNCTIONAL RESIDUAL CAPACITY (FRC): Volume of gas remaining in
lung after normal expiration, cannot be measured by spirometry
because it includes residual volume:
ERV + RV
VITAL CAPACITY (VC): Volume of maximal inspiration and expiration:
IRV + TV + ERV = IC + ERV
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TOTAL LUNG CAPACITY (TLC): The volume of the lung after maximal
inspiration. The sum of all four lung volumes, cannot be measured by
spirometry because it includes residual volume:
IRV+ TV + ERV + RV = IC + FRC
DEAD SPACE: Volume of the respiratory apparatus that does not
participate in gas exchange, approximately 300 ml in normal lungs.
--ANATOMIC DEAD SPACE: Volume of the conducting airways,
approximately 150 ml
--PHYSIOLOGIC DEAD SPACE: The volume of the lung that does not
participate in gas exchange. In normal lungs, is equal to the anatomic
dead space (150 ml). May be greater in lung disease.
FORCED EXPIRATORY VOLUME in 1 SECOND (FEV1):
The volume of air that can be expired in 1 second after a maximal
inspiration. Is normally 80% of the forced vital capacity, expressed as
FEV1/FVC. In restrictive lung disease both FEV1 and FVC decrease ,
thus the ratio remains greater than or equal to 0.8. In obstructive lung
disease, FEV1 is reduced more than the FVC, thus the FEV1/FVC ratio is
less than 0.8.
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Unit twenty nine and thrity
Urine examination
1. Sample preparation
1. Obtain fresh urine sample
2. Centrifuge 10-15 ml at 1500 to 3000 rpm for 5 minutes
3. Decant supernatant and resuspend remainder of urine
4. Place 1 drop of urine on slide and apply cover slip
2. Examination
1. Urine Cells
1. Urine White Blood Cells
1. Normal <2/hpf in men and <5/hpf in women
2. Urine Red Blood Cells
1. Normal <3/hpf
2. Dysmorphic RBCs suggest glomerular disease
3. Epithelial cells
1. Transitional epithelial cells are normally present
2. Squamous epithelial cells suggest
contamination
3. Renal tubule epithelial cells suggest renal
disease
Bacteria
4. Five bacteria per hpf represents 100,000 CFU/ml
5. Diagnostic for Urinary Tract Infection
1. Men: Any bacteria
2. Women: 5 or more bacteria per hpf
Urine Crystals
Types
2. Calcium oxalate crystals (square envelope shape)
3. Triple phosphate crystals (coffin lid shape)
1. Associated with increased Urine pH (alkaline)
2. Associated with Proteus Urinary Tract Infection
4. Uric Acid crystals (diamond shape)
5. Cystine crystals (hexagonal shape)
6. urine casts
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References
1- Beasley, Brenda. Understanding EKGs: (2002). A Practical
Approach. 2nd ed. Upper Saddle River, NJ: Prentice Hall,
2- Memmler,Ruth Lundeen . (1990). structure and function of
the human body ( fourth edition )
3- Mulla Afaf ,Abed ulwahid Ibrahim , Yousife Youbart
Practical clinical physiology ( first edition ) ,(1989).
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