Download Blood - Dr Magrann

Blood
Blood
Blood is not an epithelial tissue, and it’s
not loose or dense connective tissue; it’s
classified as a “special connective tissue”.
 You have about 5 liters of blood, but that
is only half of the body fluid.
 The other half includes fluid around each
cell, and joint fluids, etc.

Blood
PLASMA  EXTRACELLULAR FLUID
↑
↓
SYNOVIAL FLUIDS, ETC
Blood consists of the following:
Plasma
 Red blood cells
 White blood cells
 Platelets

FUN FACTS
In one day, your blood travels nearly
12,000 miles.
 Your heart beats around 35 million times
per year. Your heart pumps a million
barrels of blood during the average
lifetime -- enough to fill three
supertankers. If an artery is cut, blood will
shoot out 30 feet.

Plasma
Plasma is what the blood cells float around in. If
you spin a blood sample in a test tube, the red
blood cells sink to the bottom, and you’ll see the
yellow plasma on top.
 Some people who need blood just need the
packed RBCs, some need the platelets, others
need the plasma, and some need whole blood,
which is both plasma and RBCs.
 The plasma also carries around the platelets and
some white blood cells.

Overview: Composition of Blood
Figure 17.1
PLASMA CONTENTS
Water (90%)
Dissolved substances (10%)


–
Proteins




–
Nutrients


–
–
–
Albumin (egg white). Most common protein in blood
(homeostasis)
Antibodies
Clotting factors called fibrinogen and fibrin.
Lipoproteins (move fats through blood: HDL, LDL)
Glucose (main energy source)
Amino Acids (builds proteins)
Wastes (urea)
Gases (O2, CO2, Nitrogen)
Electrolytes = ions (Na+, K+, Cl-, Ca++)
Blood Cells
ERYTHROCYTES
(Red blood cells)


5 million
Like a doughnut with the hole not fully
cut out.
– These are among the smallest cells in the
body
– They have no nucleus
– Biconcave to increase surface area
– Filled with hemoglobin (Hgb), which carries
O2 throughout the body. Oxygenated Hgb is
bright red, deoxy Hgb is deeper red, almost
a bluish-purple.
Erythrocytes
Hemoglobin Molecule
Hemoglobin Molecule
ERYTHROCYTES:
– Average life span is 120 days. Old ones are
destroyed in the spleen and liver, and Hgb is
recycled.
– In one day, 100 billion of these cells are
destroyed, and 100 billion are made: where?
– Red marrow.
Microbiology

To understand the function of white blood
cells, you will need to learn some general
concepts and terminology from
Microbiology:
– Pathogen
– General size of bacteria and viruses
– Antigen
Pathogen
“Path” = disease “ogen” = generating
A pathogen is something that causes
disease.
 A biological pathogen is a bacterium,
virus, fungi, yeast, protozoa, worms, etc.
 A non-biological pathogen can be a toxic
chemical, asbestos, etc.
 Usually, the term “pathogen” refers to a
biological pathogen.

Sizes of Pathogens

Bacteria are so small that hundreds of them can
fit inside one white blood cell.


However, bacteria usually do not invade body cells.
They live between the cells of the body, using up
nutrients in the area, and they cause harm by
secreting toxins.
Viruses are so small that thousands of them can
fit inside the NUCLEUS of one white blood cell.


They always try to invade body cells because they
need a piece of our DNA or RNA in order to replicate.
When a body cell has been invaded by a virus, the
entire cell must be killed by a white blood cell.
Antigen
An antigen is anything that causes an
immune response, which isn't necessarily
a biological pathogen (disease-causing
organism).
 A non-biological antigen can be pollen,
dust, grass, or anything that a person is
allergic to.
 Pollen can be an antigen to a person with
allergies, but it is not an antigen to a
person without allergies, because no
immune response was launched.

LEUKOCYTES (White blood cells)
all fight infection

BASOPHILS
– MAST CELL
EOSINOPHILS
 NEUTROPHILS
 MONOCYTES

– MACROPHAGES

LYMPHOCYTES
– B CELLS
– T CELLS
BASOPHILS

Basophils – only about
0.5% of all leukocytes
– Granules secrete
histamines (vasodilation;
more WBCs can get to the
infection site)
– Antihistamines interfere
with the function of
basophils.
– Mast Cell: a basophil that
leaves the blood vessel
and enters the tissues.
Eosinophils

Eosinophils –
compose 1-4% of all
WBCs
– Play roles in:
 Ending allergic
reactions, parasitic
infections
 During these conditions
they increase in
numbers
Neutrophils
Neutrophils – most
numerous WBC
 First to respond to
infection

– Phagocytize and destroy
bacteria
– Also destroy bacterial
toxins in body fluids
– Nucleus – has two to six
lobes
Neutrophils
Neutrophils are the white blood cells that
contribute to immunity mainly by
engulfing BACTERIA and foreign bodies
(thorns, dirt, etc) in a process called
phagocytosis.
 They release the contents of their
lysosomes onto the invader, dissolving it.
 When a bacterium has a capsule, it makes
it hard to phagocytize, so the neutrophil
requires opsonization by antibodies.

Opsonization
Some bacteria have evolved a slippery
capsule around them as a defense against
phagocytosis. The neutrophil cannot
engulf this type of bacteria. Neither can a
macrophage.
 When an antibody attaches to this type of
bacteria, the neutrophil can now grab onto
the antibody like a handle, enabling it to
phagocytize the bacteria.
 This process of facilitation of phagocytosis
is called opsonization.

When an invading bacteria has the antibody
attached to its cell membrane, the entire
structure is now called an antigen-antibody
complex.
 If a bacterium does not have a capsule, the
neutrophil can destroy it without opsonization.
The antibody can also destroy the bacterium by
itself by popping the cell membrane.
 But when a capsule is present, the neutrophil
and antibody work best together.
 Neutrophils are also the ones that
primarily destroy the dissolved toxins that
bacteria secrete into body fluids.

Monocytes




Comprise about 5% of all WBC’s.
Like neutrophils, they phagocytize
(eat) bacteria, old cells, and
foreign bodies. They have more
types of lysosome enzymes than
neutrophils so they are better at
killing difficult pathogens.
They also use antibodies for
opsonization.
When they leave the
bloodstream and enter the
tissues, they are called
MACROPHAGES.
WBC’s leave the blood vessel
to enter the tissues
What’s the Difference between Neutrophils and
Monocytes/Macrophages?





There are 10x more neutrophils in the bloodstream than
monocytes/Macrophages. Consider neutrophils to be
the most numerous white blood cell.
However, there are more macrophages in the tissues of
the body. They are everywhere!
Neutrophils live only a few days. Monocytes/Macrophages
live a few months. Lymphocytes live for years.
Monocytes/Macrophages are larger and slower than
neutrophils, but they can phagocytize larger organisms
and more of them.
Neutrophils usually just phagocytize bacteria until they
die. Macrophages phagocytize and then take pieces of the
dead bacteria and present them to lymphocytes so a
larger immune response can occur.
Differences in Function


There are two types of phagocytes: Neutrophils and
macrophages.
– Neutrophils and macrophages both mainly function by
phagocytizing bacteria (not viruses).
Lymphocytes are mostly needed to kill off body cells
infected by viruses.
Differences in Function
Neutrophils just phagocytize bacteria and secrete
chemicals to recruit more white blood cells to the
site.
 Unlike neutrophils, macrophages have surface
receptors; these "recognize" the surface of the
pathogen’s cell membrane.
 Macrophages phagocytize the bacteria, pop their
lysosomes onto it, and dissolve it, except for
some pieces of the bacteria’s cell membrane.
 The macrophage places these pieces of bacteria
on its own cell membrane, and finds a
lymphocyte to present it to.

Differences in Function
Macrophages present these pieces to T cell
lymphocytes and to B cells lymphocytes.
 The lymphocyte feels the shape of the bacteria
pieces on top of the macrophage, (this is called
“antigen presentation”) and the lymphocyte can
then launch an attack on the rest of the bacteria
still alive in the body.
 In this way, the macrophage recruits even more
lymphocytes to join the war.
 So, what is a lymphocyte?

Lymphocytes

20–45% of WBCs
– The most important cells of the
immune system
– There are two types of
lymphocytes; one type is
effective in fighting infectious
organisms like body cells
infected with viruses
– Both types of lymphocytes act
against a specific foreign
molecule (antigen)
Lymphocytes
Two main classes of lymphocyte

–
–
B cells – Originate in the bone marrow,
mature into plasma cells. A mature
plasma cell fights infection by
producing antibodies
T cells – Originate in the thymus gland.
They attack foreign cells directly (including
organ transplants!). They can also kill
viruses.
Lymphocytes
B cells – mature into plasma cells
Plasma cells secrete antibodies; the
plasma cell’s antibodies are what
kills the attacking cell.
Antibodies attack in two ways:



–
–
They attach to bacteria and pop the cell
membrane
They attach to encapsulated bacteria to
help neutrophils and macrophages to
phagocytize them.
Disorder of B-cell Lymphocytes
Mononucleosis: Epstein Barr virus
attacks B lymphocytes. It is
characterized by inflammation of lymph
vessels (lymphangitis).

–
Lymphangitis: lymph vessel inflammation;
usually from infection.
Infected lymphocytes have a
characteristic scalloped
edge where they touch
RBC’s
Function of a B Lymphocyte
Figure 17.6b
T-cell Lymphocytes





T cells – coordinate the immune response by
recruiting other white blood cells.
They can directly destroy bacteria by popping their cell
membrane.
T cells can also directly destroy foreign cells by
popping the cell membrane.
They do not need to phagocytize the invading cell.
They do not need the assistance of antibodies.
T-cells can therefore kill a body cell that has become
infected with viruses.
T-Cell
T-cell Lymphocytes

T cells are the cells that attack
organ transplants!



Immunosuppression drugs are designed to
inhibit the action of T cells.
T cells are attacked by the HIV (AIDS)
virus.
The thymus gland secrets certain
hormones which can cause T cells to
become immunocompetent (makes the
cells mature and start to work)
T Cells
There are several types of T cells. The main types are
 Cytotoxic (Killer) T cells
– Go out and directly kill bacteria or infected host cells
 Helper T cells
– Release chemicals called “cytokines” to call in more
white blood cells of all types to join in the war. They
also present the macrophage’s antigen to a plasma
cell, which causes the plasma cell to produce
antibodies against that particular bacteria.
 Suppressor T cells
– Stop the immune process when it is over, and also "tell" some
plasma cells to "remember" how to destroy that specific
pathogen. Those plasma B-cells are then called Memory B-Cells.
They can react to the same pathogen faster, the next time it
invades because Memory B-cells already have the proper
antibodies stored up for that pathogen.
Killer TCell
Virus-Infected Cell
Function of a T- Lymphocyte
Figure 17.6a
Summary




A pathogen somehow gets past the body's physical and
chemical barriers and the inflammation response.
The pathogen is engulfed by a macrophage (or
neutrophil).
The macrophage releases the contents of its lysosomes
onto the bacterium and dissolves most of it. There are
still some pieces of the bacterium’s cell membrane left.
The macrophage then forces the surface proteins of the
bacterium (antigens) to it's own cell surface.
Helper T-Cells touch these surface antigens, make a
copy of their shape, and present them to B-cells to make
antibodies against them.
Summary






These Helper T-Cells begin to multiply and have two main roles.
The first is to activate B-Cells and "tell" them how to neutralize the
pathogen by presenting the pieces of the bacterium cell membrane
so the B-cells can turn into plasma cells which make the antibodies.
– The B-Cells (now called Plasma cells because they have been
activated) begin to multiply and produce the antibodies to
neutralize this specific pathogen.
The second role of Helper T-Cells is to activate the Killer T-Cells by
secreting cytokines.
Killer T-Cells can either destroy the pathogen itself (bacteria), or
destroy the entire body cell which is infected (viruses).
When the immune response is over, Suppressor T-Cells stop the
process and also "tell" some B-Cells (plasma cells) to "remember"
how to destroy that specific pathogen.
Those B-cells (plasma cells) now become Memory B-Cells.
Antibodies
Antibodies (also known as immunoglobulins,
abbreviated Ig) are proteins made by plasma
cells.
 They are used to identify and neutralize foreign
objects, such as bacteria and viruses.
 They are typically made of basic structural
units—each with two large heavy chains and two
small light chains—to form a unit shaped like the
letter “Y”

A Typical
Antibody
The tips of the “Y”
have receptors that
are specific for a
particular antigen.
The stem of the “Y”
can be grasped by a
phagocyte.
Antibodies
The small region at the tip of the protein is
extremely variable, allowing millions of
antibodies with slightly different tip structures,
or antigen binding sites, to exist.
 This region is known as the hypervariable
region. Each of these variants can bind to a
different target, known as an antigen.
 This huge diversity of antibodies allows the
immune system to recognize an equally wide
diversity of antigens.

Antibodies




Some of these “Y” shaped units
exist by themselves (monomers)
Some are in pairs (dimers)
Some are in a cluster of five
(pentamers)
There are five different antibody
types , which perform different
roles, and help direct the
appropriate immune response for
each different type of foreign
object they encounter.
Types of
Antibodies
Capsule
Pops
the cell
Virus
Opsonization
Bacteria
Bacteria
Antibodies
Plasma
Cell
Pops the cell
Cytokines
Phagocytosis
STOP
Presentation
Neutrophil
Macrophage
(Monocyte
in bloodstream)
B-Cell
Helper
T-Cell
Killer
T-Cell
Lymphocytes
Suppressor
T-Cell
IMMUNITY
B Cells that have matured into plasma
cells which have made antibodies are now
called Memory lymphocytes, after their
first war.
 Most people are sick more often as
children than as adults in their 20s
through 30s because we build up many
varieties of memory lymphocytes during
childhood, providing immunity from more
and more antigens during adulthood.

Myasthenia gravis
Myasthenia gravis (MG): autoimmune
disease where antibodies destroy or block
receptors for acetylcholine, a
neurotransmitter.
 Causes muscle paralysis.
 First attacks small muscles especially
those that keep eyes open; will spread to
diaphragm  death.
 To stave off effects, do thymectomy.

PLATELETS
Very small compared to all other blood cells.
These are pieces of another cell found in the red
marrow called a MEGAKARYOCYTE.
 Pieces break off of a megakaryocte and are
known as platelets.
 When a platelet encounters a broken blood
vessel it releases a substance that clots blood.
 Platelets are responsible for clot formation.

Platelets
Platelets need certain proteins in the
plasma called CLOTTING FACTORS in
order for them to become activated and
form a clot.
 Two main clotting factors are called
FIBRIN and FIBRINOGEN.

Platelets

Cell fragments
– Break off from
megakaryocytes

Function in clotting of
blood
Platelets
Megakaryocyte
Blood
Clot
Summary of Formed Elements
Table 17.1 (1)
Summary of Formed Elements
Table 17.1 (2)
Life span, from longest-lived
to shortest-lived:
Lymphocytes
 Erythrocytes
 Platelets
 Neutrophils

STEM CELLS IN THE RED MARROW
STEM CELL: A cell that has not matured and
differentiated yet.
 An embryo has lots of stem cells which have not
decided to become a nerve cell, muscle cell, liver
cell, etc. Stem cells become the type of cell the
body needs. The placenta of a newborn infant
has many of these stem cells, too, but not as
many as an embryo. That’s why people want to
research stem cells on embryos; there are more
stem cells there.

Stem Cells
The first step for a stem cell is to
DIFFERENTIATE, which is to decide what
system of cells it will belong to. A stem cell that
matures in the bone marrow will become a
blood cell.
 Adults don’t have too many stem cells that are
so immature that they have not yet decided
what system of cells to belong to.
 Most of our stem cells have matured to the next
step, which is that they have decided what
system to evolve into.
 An adult has stem cells that will ONLY become
blood, nerve tissue, organs, etc.

Blood Cell Formation
Hematopoiesis – process by which blood
cells are formed
 100 billion new blood cells formed each
day
 The plasma proteins are made in the liver.
 The blood cells are made in the red
marrow.

Bone Marrow as the Site of
Hematopoiesis

Bone marrow – located within all bones
– Red marrow – actively generates new blood
cells
 Contains immature erythrocytes
 Remains in epiphyses, girdles, and axial skeleton
Bone Marrow as the Site of
Hematopoiesis
Yellow marrow – dormant
 Contains many fat cells
 Located in the long bones of adults
RED BONE MARROW
Most blood cells mature in the red bone
marrow.
 When they are almost completely mature,
they are released into the bloodstream.
 When they are old, they are destroyed in
the spleen and liver.

Cell Lines in Blood Cell
Formation
All blood cells originate in bone marrow
 All originate from one cell type – blood
stem cell

– Erythroblasts – give rise to red blood cells
– Lymphoblasts – give rise to lymphocytes
– Myeloblasts – give rise to all other white blood
cells
Stages of
Differentiation of
Red Blood Cells
RBC Development

ERYTHROBLASTS mature until they
are ready to enter the circulation. The
nucleus gets pinched off as it enters the
blood vessel. When a RBC loses its
nucleus, it gains room for more
hemoglobin. Some bits of its nucleus are
still there for about 2 days, so during this
time, they are called
RETICULOCYTES.
RBC Development


A mature RBC is called an
ERYTHROCYTE, which circulates in the
blood.
If the body makes too few erythrocytes
it can lead to one form of ANEMIA.
ERYTHROBLASTS

These mature into
RETICULOCYTES, a
RBC with bits of
nucleus material,
which later dissolves
to make room for
more Hgb. It is now
called an
ERYTHROCYTE.
LYMPHOBLASTS
Give rise to lymphocytes
MYELOBLASTS
These are the stem cells that mature into
the other leukocytes:
Neutrophil, macrophage, eosinophil,
basophil, platelets.
Leukemia
Leukemia is cancer of the stem cells.
See all these different types of stem cells?
That’s about how many types of leukemia
there are.
Stages of
Differentiation
of White Blood
Cells
Figure 17.9
Disorders of RBCs
Polycythemia
 Anemia

–
–
–
–
–
–
Too few RBC’s
Iron deficiency
Hemorrhagic anemia (person lost blood)
Pernicious anemia (lack of vitamin B12 or intrinsic factor)
Excess RBC destruction (immune disorder or infection)
Hemoglobin abnormalities
 Thalassemia
 Sickle cell disease
 Megaloblastic anemia (pernicious anemia)
Polycythemia
Too many RBC’s; can cause clots. Need to donate
blood frequently
ANEMIA

Any condition of RED BLOOD CELLS in
which the blood’s capacity for carrying
oxygen is diminished.
Anemia


Characteristic sign of anemia: see
reticulocytes in the blood (immature red
blood cells).
Remnants of the nucleus are still in the
cell.
Reticulocytes
Anemia can be caused by many things. One
type of anemia is from too few RBC’s.
Anemia can also be caused from
Iron Deficiency
IRON DEFICIENCY ANEMIA
that was treated with blood transfusion
These are the healthy RBCs from
blood transfusion
More Causes of Anemia
Hemorrhagic anemia: loss of blood
 Pernicious anemia: lack of vitamin B12 or
intrinsic factor, which is needed to make
the hemoglobin in a RBC
 Excess RBC destruction (from an
autoimmune disease, infection, etc)
 Genetic defect in Hemoglobin (deforms
the cell)

Thalassemia
A form of anemia where the RBCs have abnormal
hemoglobin that deforms the cells
TEAR DROP
TARGET CELLS
SPHEROCYTE
Sickle Cell Disease

Present in African Americans more than
in other groups, and is always
characterized by sickled erythrocytes.
Sickle Cell Anemia
SICKLE CELL
Megaloblastic Anemia
(Large RBCs: Note that the lymphocyte is the
same size as the huge RBCs)
Hematocrit





A quick screening test for anemia is the
hematocrit.
A drop of blood is drawn up a small glass
capillary tube and the tube is centrifuged to
pack the red blood cells at the bottom with the
plasma on top.
Hematocrit measures the percentage of blood
volume that consists of erythrocytes.
The hematocrit is the ratio of packed red blood
cells to total blood volume.
Normal is about 45% (46% for men and 38%
for women.)
Hematocrit
LEUKEMIA
Cancer of the blood is called leukemia. It
actually only involves the white blood cells.
 Something goes wrong in one stem cell, and it
starts making huge amounts of clones of itself
which don’t work right and not enough normal
white blood cells are made. Therefore, the body
cannot fight infection. So, the immature white
cells are sent into the bloodstream. It’s better to
send a young cell with no weapons to the war
than to send nothing at all!
 Think of Leukemia as too few mature
white blood cells.
 Even though the WBC count is high, they are all
immature forms.

Disorders of WBCs

Disorders of leukocytes
– Leukemia – too few mature WBC’s (may see
increase in immature forms); a form of cancer
– Classified as lymphoblastic (too many
immature lymphocytes) or myeloblastic (too
many immature neutrophils)
Bone Marrow Transplant
People with severe leukemia may need a bone
marrow transplant.
 First, all of their WBC’s have to be killed off with
a medicine because they are mostly
malfunctioning anyway.
 A donor has a small cylinder of bone removed
from their hip. This is ground up and given by
i.v. to the recipient.
 The new WBC’s may kill the patient or it may
save their life. It is done as a last resort.

Disorders of Platelets
– Thrombocytopenia
 Abnormally low
concentration of platelets
 Blood does not clot
properly
HEMOPHILIA
A hereditary disease of males, where they are
unable to clot properly because they are missing
some clotting factors.
 When they get even a slight bump or bruise
they have to have an intravenous infusion of
clotting factors or they will bleed to death.
 This is probably the disease that was in the
genes of Henry VIII, which caused all of his
male children to become weak and die in
infancy.

Blood Clots

Thrombus
– A clot in a vessel

Embolism
– a thrombus that broke away and
travels in the blood stream.
– It usually lodges in a smaller blood
vessel and blocks circulation distal
to that point.
Blood Clots
Thrombus
 Embolism

Thrombus
Thrombus
BLOOD TYPING: The ABO SYSTEM
Blood typing is the technique for
determining which specific protein type is
present on RBCs.
 Only certain types of blood transfusions
are safe because the outer membranes of
the red blood cells carry certain types of
proteins that another person’s body will
think is a foreign body and reject it.

BLOOD TYPING





These proteins are called antigens (something
that causes an allergic reaction). There are two
types of blood antigens: Type A and Type B.
A person with Type A antigens on their blood
cells have Type A blood.
A person with Type B antigens have Type B
blood.
A person with both types has type AB blood.
A person with neither antigen has type O blood.
BLOOD TYPING





If a person with type A blood gets a transfusion
of type B antigens (from Type B or Type AB, the
donated blood will clump in masses
(coagulation), and the person will die.
The same is true for a type B person getting
type A or AB blood.
Type O- blood is called the universal donor,
because there are no antigens, so that blood
can be donated to anyone.
Type AB+ blood is considered the universal
acceptor, because they can use any other type
of blood. This blood type is fairly rare.
The rarest blood type is AB negative.
RH FACTOR
There is another term that follows the
blood type. The term is “positive” or
“negative”. This refers to the presence of
another type of protein, called the Rh
factor. A person with type B blood and
has the Rh factor is called B positive.
 A person with type B blood and no Rh
factor is called B negative.

RH FACTOR

The reason this is so important is that if
an Rh- mother has an Rh+ fetus in her
womb (from an Rh+ father), her
antibodies will attack the red blood cells of
the fetus because her body detects the Rh
protein on the baby’s red blood cells and
thinks they are foreign objects. This is
called Hemolytic Disease of the Newborn
(HDN).
HDN
This can be prevented if the doctor knows
the mother is Rh- and the father is Rh+,
because that means the baby has a 50%
chance of being Rh+ like the father.
 Therefore, anytime a mother is Rh-, even
if the mother says the father is Rh-, you
can’t be sure who the father is, so they
will proceed as though the baby may be
Rh +.
 They will give her an injection of a
medicine (Rhogam) that will prevent her
immune system from attacking the baby.

Rhogam





Rhogam is given at 18 weeks into the pregnancy and
again within 72 hours after giving birth.
It is usually given within 2 hours after giving birth since
you can’t trust the patient to return after they leave the
hospital.
The first baby is not at risk; during the first birth (or
miscarriage), the placenta tears away and that’s when
the baby’s blood cells get into the mother’s bloodstream.
She then forms antibodies against the Rh factor, which
are ready to attack the second fetus.
The baby does not make the Rh factor until about 18
weeks into the pregnancy.
IMMUNE SYSTEM
INFLAMMATORY REACTION: When you get
stuck by a thorn or have an infected cut, the
body goes through a series of events called an
inflammatory reaction.
 Four outward signs:

–
–
–
–
Redness (erythema or rubor)
Heat (calor)
Swelling (edema)
Pain (dolor)
INFLAMMATORY REACTION




Redness is caused from the blood vessels dilating to
allow more blood flow to the area. Within the blood are
platelets to clot the blood, proteins to repair the
damage, and macrophages, which are white blood cells
that eat up the foreign body, bacteria, or the dead cells.
Heat is caused because of the extra amount of warm
blood flow to the area.
Swelling is caused from the plasma that leaks out of
the swollen blood vessels.
Pain is caused from the pressure of the extra fluid
pressing on nerves in the area.
ADAPTIVE IMMUNITY

Two types of Adaptive Immunity
– ACTIVE immunity
 Naturally Acquired
 Artificially Acquired
You can also think
of it this way
– PASSIVE immunity
 Naturally Acquired
 Artificially Acquired
Active Immunity

Naturally Acquired
– The body is naturally exposed to an infectious
agent and launches an immune reaction

Artificially Acquired
– The person is injected with a weakened
(attenuated) or killed organism, as found in a
vaccination
Naturally Acquired
Active Immunity
This is when the body is exposed to an
infectious agent and the body has to work to
produce antibodies which specifically attack that
infectious agent.
 The white blood cells secrete these antibodies
which will continue to circulate sometimes for
years, ready to attack that type of bacteria and
cause them to pop like a balloon before the
body can become sick.

Naturally Acquired
Active Immunity
– You catch a cold and eventually get better. You can
never get the same cold virus twice because you will
have become immune to it. Your next cold is from a
different virus. There are hundreds of thousands of
cold viruses; that’s why there is no cure for the
common cold.
– Another example is when an unvaccinated child is
exposed to the measles at school and gets the
disease, but never gets the disease again.
However, there are some diseases that you
don’t want to get, even once, such as polio,
diphtheria, tetanus, and influenza, because the
first exposure could kill or disable you.
 For these diseases, we have vaccines which are
made of those organisms which have been
altered (attenuated) so that the body recognizes
them as foreign, but they can’t cause disease.
 That way, if the person is exposed to the real
organism later, the antibodies are already there
to kill it off without the body getting sick.

Artificially Acquired
Active Immunity

An example is when a child is vaccinated against
measles as a baby, so when he gets to school
and is exposed to the disease, he doesn’t get
sick.
Passive Immunity

Naturally Acquired
– Example is the passing of antibodies from
mother to infant in breast milk

Artificially Acquired
– Example is when a person receives an
infusion of antibodies from someone else.
Active vs. Passive Immunity
Active immunity is long-lived, and may last
for years or even a life time.
 Passive immunity is short lived, and may
last only for a few months.

NOTE: A vaccination is not the same as
receiving an anti-toxin or anti-venom
injection. More on that in Micro class.
ALLERGIES

From a hypersensitivity to substances such
as pollen or animal hair that would not
ordinarily cause a reaction. There are two
types of allergic responses:
Immediate
Delayed
Immediate allergic response
Occurs within seconds of contact with the thing
causing the allergy.
This is the case with anaphylactic allergies, where
someone who is allergic to seafood or peanuts
can actually die within minutes because the
allergic reaction is so severe the throat swells
shut and they can’t breathe.
They need an injection immediately of something
that will stop the reaction.
Delayed allergic response
Delayed allergic response is when the body’s
first exposure to the substance will not
cause a reaction, but all exposures
afterward will trigger the response.
An example is poison ivy.
You won’t itch the first time you touch it.
AUTOIMMUNE DISEASE

A hereditary problem where the body
thinks its own tissues are foreign bodies,
and it constantly tries to kill off its own
tissues.