2. Functions of Blood
• Blood is the only liquid connective tissue.
• Blood has three main functions.
• 1. Transportation- blood transports oxygen from the
lungs to the cells throughout the body.
• 2. Regulation- blood helps regular pH of body fluids
and also the temperature of the body.
• 3. Protection- blood clots protect against excessive
loss of blood. White blood cells patrol the body and
protect it against disease.
3. Components of Whole Blood
• Blood is denser and stickier than water.
• Blood is kept at a temperature of about
100.4 F and has a slightly alkaline pH.
• Blood constitutes about 8% of the total
body weight.
• The average male human contains 5-6 liters
of blood with the average female human
containing 4-5 liters of blood.
4. • Whole blood is composed of two parts: blood
plasma and formed elements.
• Blood is 45% formed elements and 55%
plasma.
• 99% of the formed elements are red blood
cells (RBC) and less than 1% of the blood is
white blood cells and platelets.
• When blood is centrifuged, the formed
elements like the RBC’s sink to the bottom of
the tube and the liquid plasma floats on top.
5.
6. Blood Plasma
• When formed elements are removed, a straw colored
liquid called blood plasma is left.
• Plasma is 91.5% water, 7% proteins, and 1.5% other
dissolved solutes.
• Proteins in the blood are synthesized by the liver.
• Some proteins include:
• Albumins-most plentiful, (egg whites)
• Globulins- antibodies and immunoglobulins
• Fibrinogen- blood clots
7.
8. Formed Elements
This includes the following:
Red blood cells (RBC)
Platelets
White Blood Cells (WBC)
Granular leukocytes
Neutrophils
Eosinophils
Basophils
Agranular Leukocytes
T and B lymphocytes and natural killer
cells
Monocytes
9. Formation of Blood Cells
• The process in which the formed elements of blood develop
is called hemopoiesis.
• Before birth, this occurs in the yolk sac of the embryo and
later in the liver, spleen, thymus and lymph nodes of the
fetus.
• In the last three months before birth and the rest of human
life, red bone marrow becomes the primary site for blood
formation.
10. Red Bone Marrow
• High vascular connective tissue located
in spongy bone tissue.
• Red bone marrow cells are derived from
pluripotent stem cells.
• These cells have the capacity to develop
into several different types of cells.
• Pluripotent stems cells further develop
into myeloid stem cells and lymphoid
stem cells.
11.
12. Red Blood Cells
• RBCs are also called erythrocytes.
• They contain the oxygen-carrying
protein hemoglobin which gives whole
blood its red color.
• A healthy adult male typically has 5.4
million red blood cells per microliter of
blood and a healthy adult female has
about 4.8 million per microliter.
13.
14. • To maintain normal numbers, new mature RBCs must
enter the bloodstream at 2 million per second; a pace
that balancing the RBC destruction.
• Mature RBC do not have a nucleus and cannot divide
or carry out metabolic activities.
• RBCs are a biconcave disk which increases the surface
area for gas diffusion.
15. RBC Life Cycle
• RBCs only live about 120 days because of wear and tear and
are removed from circulation.
• 1. Macrophages in the spleen, liver and red bone marrow
phagocytize ruptured and worn-out cells splitting the heme
and globin from each other.
• 2. Globin is broken down into amino acids and reused.
• 3. Iron is removed from the heme portion and hooks up
with the plasma protein transferrin which acts as a
transporter.
• 4. The iron-transferrin complex is carried to the red bone
marrow where it is used to create new hemoglobin.
Vitamin B-12 is also used.
16. • 5. Red blood cells are formed in the red bone
marrow.
• 6. When iron is removed from heme, the non-iron
portion of heme is converted to biliverdin and
bilirubin. Bilirubin enters the blood and transported
to the liver and secreted into bile.
• 7. In the large intestine, bacteria convert bilirubin
into urobilinogen. This can be absorbed back into
the blood, excreted as urine or excreted in feces to
give it the brown color.
17.
18. • Free iron is damaging, transferrin acts a protective
protein escort and as a result, plasma has virtually
no free iron.
• Iron overload can result when the body has too
much buildup of iron.
• The body has no method to eliminate the excess
iron.
• This can cause diseases of the heart, liver pancreas
and gonads.
20. White Blood Cells
• Unlike red blood cells, WBCs or leukocytes, have nuclei
and do not contain hemoglobin.
• They can be classified as granular or agranular depending
if they contain vesicles.
• WBCs are only made visible by staining. They are
normally clear.
• WBCs are active in the immune response of the body.
22. WBC Functions
• Some WBCs combat microbes via phagocytosis
while others types produce antibodies.
• Neutrophils response first by releasing enzymes
to destroy microbes and ingesting them.
• Monocytes take longer to reach the site of
infection but arrive in large numbers.
• Monocytes migrate into infected tissues and
become wandering macrophages that can ingest
many microbes and clean up cellular debris.
23. • Eosinophils leave the capillaries and enter interstitial
fluid to combat inflammation in allergic reactions.
• They phagocytize antigen-antibody complexes and
are effective against certain parasitic worms.
• A high eosinophil count indicates an allergic
condition or parasitic infection.
24. • Basophils are also involved in inflammatory and
allergic reactions.
• They leave the capillaries and enter the tissues and
help release histamine, heparin and serotonin which
intensify the inflammatory reaction.
25. • B cells, T Cells and natural killer cells are WBC that
are active in the immune system.
• B cells become plasma cells that produce antibodies
and inactivate toxins.
• T cells attack microbes directly.
• NKC attack microbes and tumor cells.
26.
27. • White blood cells and other nucleated body
cells have MHC proteins.
• Red blood cells possess group antigens but
lack MHC antigens.
• Tissue transplant rejections happen in part
to MHC proteins being incompatible.
28. • Red blood cell antigens do make blood
donations difficult because of
incompatibilities but NOT due to MHC.
• Many WBC’s live only a few days and during
cycles of infection, some only live a few
hours.
• However, there are some WBCs that are in
the body for years to provide continued
protection as memory cells.
29.
30. WBC Counts
• Leukocytosis is an increase in the number of WBCs as a
protective response to invading microbes, strenuous
exercise, anesthesia and surgery.
• Determining the percentage of each type of WBC in a
blood sample is useful for diagnosing a condition because
each type of WBC plays a different role in the immune
response.
• This test is called the differential white blood count.
• Leukopenia is an abnormally low level of WBCs and can be
caused by radiation, shock and other chemical exposure.
32. Platelets
• Pluripotent cells also differentiate into platelets.
• They are disk shaped and have many vesicles but no
nucleus.
• When blood vessels are damaged, platelets help stop blood
loss by forming a platelet plug.
• The platelets also contain chemicals that promote blood
clotting.
• Platelets only live for 5-9 days.
33. Platelet Plug Formation
• 1. Platelets contact and stick to parts
of the damaged blood vessel. This is
called platelet adhesion.
34. • 2. The platelets become activated and
they extend many projections that
enable them to contact and interact
with each other. They release
chemicals contained in their vesicles
which decrease blood flow. This is
called platelet release reaction.
35. • 3. The chemicals released makes all the
platelets in the area sticky and causes them
to clump together. This is called platelet
aggregation. Eventually large numbers
form and a platelet plug forms and stops
blood leakage.
36.
37.
38. Blood Groups and Blood Types
• The surfaces of blood cells contain genetically
determined assortments of proteins and lipids.
• Based on the presence or absence of certain antigens,
blood is categorized into different blood groups.
• Within each blood group, there may be different blood
types.
• There are at least 24 blood groups and 100 or so
different antigens.
• The major ones are ABO and Rh blood groups.
39.
40.
41. Rh factor and Rh disease
• The Rh blood group is named for the rhesus
monkey in which it was first discovered.
• People whose RBC’s have the Rh antigen are Rh +
and people who lack the antigen are Rh-.
• Under normal conditions, blood plasma does NOT
contain anti-Rh antibodies.
42. • If an Rh negative person receives a transfusion of
Rh positive blood however, the immune system
starts to make anti-Rh antibodies that remain in
the blood.
• Rh disease or hemolytic disease of the
newborn (HDN) is a problem that results
from Rh incompatibility between a mother
and her fetus.
43. • Normally no direct contact occurs maternal and fetal
blood however if a small amount of fetal Rh+ blood leaks
into an Rh- mother, the mother will develop anti-Rh
antibodies.
• The greatest possibility of blood transfer occurs during
delivery so the first born child is typically un-affected.
• Subsequent children are at risk if the fetus happens to be
Rh+ since the mother has anti-Rh antibodies in her
system.
• These antibodies will attack the fetus causing life-
threatening hemolysis or rupture of RBC’s.
44. • If the mother and infant are Rh+, no complications
will result since Rh+ people cannot make anti-Rh
antibodies.
• Issues only arise when the baby and mother are
opposite and the child is NOT the first born child.
