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Chapter 18
Blood
Blood Disorders Group Project
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Anemia
Polycythemia
Leukemia
Mononucleosis (infectious)
Hemophelia
Sickle Cell Anemia
Von Willebrand Disease
Hemochromatosis
Diamond Blackfan Anemia
Deep Vein Thrombosis
Thalassemia
Prevention and treatment of Heart Diseases
Stroke- Thromboembolyic condition
Blood
 Unique tissue- The only fluid tissue in
the human body
 Classified as a connective tissue
 Living cells = formed elements
 Non-living matrix = plasma
 Fibers- are not present, except during
clotting
 Fibrin- are the fibers found during clotting
Blood
Physical characteristics and volume
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Erythrocytes (red blood cells) make
up 45% of blood
Leukocytes (white blood cells)
combined with Platelets (cell
fragments) makes up less than 1%
of blood
Plasma (fluid matrix) makes up 55%
of the blood
Physical Characteristics of Blood
 Color range
Oxygen-rich blood is scarlet red
Oxygen-poor blood is dull, dark red
 pH must remain between 7.35–7.45
 Blood temperature is slightly higher than
body temperature
Physical Characteristics of Blood
 Sticky-
blood has a sticky feel to it
 Opaque- light does not pass through it
 Salty- to the taste
 Heavier than water and more viscous
when pouring.
 8% of the body weight is made up of
blood
 Males- 5-6 liters
Females- 4-5 liters
 Why do males have more?
Functions of blood
•
Substance Distribution
1.
Oxygen from the lungs and nutrients from
the digestive system is carried to the body
cells
Waste transported away from the body
cells
Hormones- transported throughout the
body to the target areas
body temperature- maintained by
absorption and distribution of heat
2.
3.
4.
Functions of blood
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1)
2)
3)
4)
Protection
Body pH is maintained through the
help of the blood.
Fluid volume- proper balance is kept
Blood loss- is prevented by the
clotting process.
Infection- prevented by the help of
the white blood cells, antibodies and
proteins.
Plasma Proteins
• Albumin – regulates osmotic pressure
• Clotting proteins – help to stem blood
loss when a blood vessel is injured
• Antibodies – help protect the body from
antigens
Formed Elements
 Erythrocytes = red blood cells
 Leukocytes = white blood cells
 Platelets = cell fragments
Erythrocytes (Red Blood Cells)
 The main function is to carry oxygen
 Anatomy of circulating erythrocytes
 Biconcave disks, more efficient- more
surface area; dynamic changes for vessels
 Essentially bags of hemoglobin
 Anucleate (no nucleus)
 Contain very few organelles and no
mitochondria (no oxygen needed);
anaerobic respiration for energy
 Outnumber white blood cells 1000:1
Hemoglobin- (part of the RBC’s)
 Iron-containing protein found in RBC’s
 Makes up 35% of the RBC’s cell weight
 Binds strongly to oxygen, but doesn’t
use it for energy
 Each hemoglobin molecule has four
oxygen binding sites
 Each erythrocyte has 250 million
hemoglobin molecules
Red Blood Cell Count
•
Female- 4.3 - 5.2 million cells per
cubic millimeter of blood
•
Male- 5.1 -5.8 million cells per cubic
millimeter of blood
•
Why do males have more?
Function of RBC’s
Carries O2 from the lungs to the body
cells
 Hemoglobin- binds to the oxygen to
carry it (heme to O2; globin to CO2)
 Iron- is important in the making of the
“heme” part of hemoglobin
 (lack of iron =anemia)
 Carbon dioxide- 20% of CO2 combines
with hemoglobin (globin part)
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Hematopoiesis
 Blood cell formation
 Occurs in red bone marrow (adults= diploe of flat
bones
 All blood cells are derived from a common stem cell
(hemocytoblast)
 Hemocytoblast differentiation
 Lymphoid stem cell produces lymphocytes
 Myeloid stem cell produces other formed elements
 RBC’s eject nucleus, and most of their organelles
when matured
Control of Erythrocyte Production
 Rate is controlled by a hormone (erythropoietin)
 Kidneys produce most erythropoietin as a
response to reduced oxygen levels in the bloodhypoxia; or an increase in tissue demands for
O2 (aerobic activity)
 Homeostasis is maintained by negative
feedback from blood oxygen levels
 Decline in number of RBC’s will also cause
hypoxia
 Testosterone- will also increase RBC production
which is why males will have more RBC’s
Control of Erythrocyte Production
Figure 10.5
Nutrients needed for production of
RBC’s
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1.
2.
3.
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Iron
65% of the body’s iron is found in the
hemoglobin
Free iron- is poisonous in the body
Iron not in the hemoglobin is stored in
proteins
B12 and folic acid- also important in
RBC production
Fate of Erythrocytes (RBC’s)
 Unable to divide, grow, or synthesize
proteins- No Nucleus
 Wear out in 100 to 120 days (lifespan)
 When worn out, are eliminated by
phagocytes in the spleen or liver
 Lost cells are replaced by division of
hemocytoblasts
Leukocytes
and
White blood cells
Leukocyte Levels in the Blood
 Normal levels are between 4,000 and 11,000
cells per millimeter
 They have nuclei and all organelles
 Abnormal leukocyte levels
 Leukocytosis
 Above 11,000 leukocytes/ml
 Generally indicates an infection
 Leukopenia
 Abnormally low leukocyte level
 Commonly caused by certain drugs
WBC’s: Protective mobile army
 Crucial in the body’s defense against disease
 These are complete cells, with a nucleus and
organelles
 Able to move into and out of blood vessels
(diapedesis)
 Can move by ameboid motion-(pseudopods)
 Can respond to chemicals released by
damaged tissues
 Their numbers can double within a few hours
in order to fight disease/sickness
Types of Leukocytes
 Granulocytes
 Granules in their
cytoplasm can be
stained
 Include
neutrophils,
eosinophils, and
basophils
Granulocytes
 Neutrophils
 most numerous type of WBC’s chemically
attracted to inflamed sites
 Act as phagocytes at active sites of infection
especially against bacteria and fungi
 Eosinophils
 found in intestines and on skin
 Found in repsonse to allergies and parasitic
worms
 Phagocytotic to foreign bodies instead of bacteria
Granulocytes
 Basophils
Have histamine/heparin containing
granules
Initiate inflammation and aid in
migration of other WBC’s
Least numerous type of WBC’s
Types of Leukocytes
 Agranulocytes
 Lack visible
cytoplasmic
granules
 Include
lymphocytes and
monocytes
Agranulocytes
 Lymphocytes
 Found in lymph tissue
 Play an important role in the immune response
 T-cells fight virus infection (T-helper cells)
 B-cells produce antibodies
 Monocytes
 Largest of the white blood cells
 Function as macrophages
 Important in fighting chronic infection
Production of Leukocytes
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Hormonally stimulated
•
Granulocytes and agranulocytes will take a
different path
•
Life span will vary greatly; depends on
wars against bacteria etc.
Thrombocytes (aka Platelets)
 They are cell fragments; not complete
cells
 Needed for the clotting process
 Normal platelet count = 250,000500,000/mm3
 They are regulated by hormones
 Anucleated (no nucleus) and will only
live for about 10 days
Blood Plasma
 Composed of approximately 90 percent water
 Includes many dissolved substances (over 100
different solutes)
 Nutrients
 Salts (metal ions)
 Respiratory gases
 Hormones
 Proteins- makes up 8%; mostly produced by
the liver
 Waste products
Hemostasis
 Stoppage of blood flow
 Result of a break in a blood vessel
 Hemostasis involves three phases
1. Vascular spasms
2. Platelet plug formation
3. Coagulation
Vascular Spasms
 Anchored platelets release serotonin
 Serotonin causes blood vessel muscles
to spasm
 Spasms narrow the blood vessel,
decreasing blood loss
Platelet Plug Formation
 Collagen fibers are exposed by a break
in a blood vessel
 Platelets become “sticky” and cling to
fibers
 Anchored platelets release chemicals to
attract more platelets
 Platelets pile up to form a platelet plug
Coagulation ( aka blood clotting)
 Injured tissues release thromboplastin
 Result is a mesh of fibrin that traps blood cells,
sealing the hole until the tissue can be repaired
 Most chemicals needed for clotting is in the
blood; just need to change balance.
 Procoagulant- chemicals that enhance or
promote clotting
 Anticoagulants- chemicals that inhibit or
prohibit blood clotting
Coagulation
 Anticoagulants are normally dominant
 Thromboplastin (released from the platelets)
call other platelets to the area and make
procoagulants dominant
 Calcium ions Ca++ are also needed
 Clotting normally takes 3-6 minutes
 May be faster in emergencies
Blood Clotting
 Blood usually clots within 3 to 6 minutes
 The clot remains as endothelium (vessels
tissue) regenerates
 Platelets and fibrin are pulled tighter
squeezes out the serum in a process known
as synerisis (plasma – the clotting agents)
 Pulls vessel closer together for repair
 The clot is broken down after tissue repair
 Fibroblast- help to form a connective tissue
patch
Fibrinolysis
 The
process of getting rid of
blood clots when you no longer
need them
 Plasmin- is the protein that is in
charge (clot buster)
 Begins within 2 days after the
clot is formed
Undesirable Clotting
 Thrombus
 A clot in an unbroken blood vessel
 Can be deadly in areas like the heart
 Embolus
 A thrombus that breaks away and floats
freely in the bloodstream
 Can later clog vessels in critical areas such
as the brain
Bleeding Disorders
 Thrombocytopenia
 Platelet deficiency
 Even normal movements can cause
bleeding from small blood vessels that
require platelets for clotting
 Hemophilia
 Hereditary bleeding disorder
 Normal clotting factors are missing
Blood Groups and Transfusions
 Large losses of blood have serious
consequences
 Loss of 15 to 30 percent causes weakness
 Loss of over 30 percent causes shock,
which can be fatal
 Transfusions are the only way to
replace blood quickly
 Transfused blood must be of the same
blood group
Human Blood Groups
 Blood contains genetically determined
proteins
 A foreign protein (antigen) may be
attacked by the immune system
 Blood is “typed” by using antibodies that
will cause blood with certain proteins to
clump (agglutination)
Human Blood Groups
 There are over 30 common red blood
cell antigens
 The most vigorous transfusion reactions
are caused by ABO and Rh blood group
antigens
ABO Blood Groups
 Based on the presence or absence of two
antigens
 Type A
 Type B
 The lack of these antigens is called
type O
ABO Blood Groups
 The presence of both A and B is called
type AB
 The presence of either A or B is called
types A and B, respectively
http://www.redcrossblood.org/learn-about-blood/blood-types
Rh Blood Groups
 Named because of the presence or
absence of one of eight Rh antigens
(agglutinogen D)
 Most Americans are Rh+
 Problems can occur in mixing Rh+ blood
into a body with Rh– blood
Rh Dangers During Pregnancy
 Danger is only when the mother is Rh–
and the father is Rh+, and the child
inherits the Rh+ factor
Rh Dangers During Pregnancy
 The mismatch of an Rh– mother carrying
an Rh+ baby can cause problems for the
unborn child
 The first pregnancy usually proceeds without
problems
 The immune system is sensitized after the first
pregnancy
 In a second pregnancy, the mother’s immune
system produces antibodies to attack the Rh+
blood (hemolytic disease of the newborn)
Blood Typing
 Blood samples are mixed with anti-A and
anti-B serum
 Coagulation or no coagulation leads to
determining blood type
 Typing for ABO and Rh factors is done in
the same manner
 Cross matching – testing for
agglutination of donor RBCs by the
recipient’s serum, and vice versa
Developmental Aspects of Blood
 Sites of blood cell formation
 The fetal liver and spleen are early sites of
blood cell formation
 Bone marrow takes over hematopoiesis by
the seventh month
 Fetal hemoglobin differs from
hemoglobin produced after birth