Anatomy and Physiology Exam 3 Questions and Correct Answers.
1. Describe the composition and physical characteristics of whole blood. Explain why it is
... [Show More] classified as a
connective tissue.
Blood is a transport fluid of the body, and is 55% plasma (water, proteins, and waste) and 45% forced
elements, which are much denser. These are the RBC’s (millions) and WBC’s (thousands). So if you
centrifuge it, the densest RBC’s move to the bottom, the WBC’s move to the middle, and the plasma is
on the surface.
Connective because it arises from the mesoderm
2. List eight functions of blood.
Transport oxygen, waste, gases, nutrients, hormones, maintain BP, maintain pH, immune defense.
3. Discuss the composition and functions of plasma.
Plasma is mostly water (92%) and proteins, like albumin. Rest is an insignificant waste products
4. Describe the structure, function, and production of erythrocytes.
These are red blood cells. The structure is they lack all organelles, meaning no mitochondria, so no use
of oxygen. They are concave discs with high surface are to maximize oxygen binding. They just
transport oxygen on their many hemoglobin molecules. Erythopoesis is the body’s production of RBC
in the bone marrow. Hypoxia stimulates it via EPO (hormone) release from the kidneys.
Erythopoesis rate is measured via amount of reticulocytes in the circulation (these are immature RBC’s).
Because they have a lifespan of 120 days, they are continuously destroyed and remade.
5. Describe the chemical makeup of hemoglobin.
Transporter of oxygen in RBC. Millions in each RBC, and they have 4 iron carrying subunits that carry an
oxygen molecule each.
6. Give examples of disorders caused by abnormalities of erythrocytes. Explain what goes wrong in each
disorder.
Anemia is characterized by a low RBC amount or hemoglobin, usually from low iron intake, increases iron
loss, or massive blood loss.
Polycythemia is an unnatural high RBC count. Can be from high altitude training (body adapts to the low
oxygen in the air) or from blood doping (introduce RBC into the body with drugs.)
Sickle cell is an autoimmune disorder where the RBC is altered via one amino acid change (glutamate to
valine) and this leads to a sickle shape in the RBC. This decreases surface are tremendously, thus
oxygen carrying capacity is lowered significantly.
Tony Berardi
2
7. List the classes, structural characteristics, and functions of leukocytes.
The body contains a much smaller amount of theses, divided into neutrophils (60%ish), eisonophils,
basophils, monocytes, lymphocytes (25%ish). Two class: granular (-ophil ones) and agranular.
Neutrophils digest all bacteria, eisonophils are for parasites and allergy, basophils are for inflammatory,
monocytes are the major phagocyets for debris in the body, and the lymphocytes are the B and T cells
in the immune system (specific immune responses to disease). Too many lymphocytes means a viral
infection~leukocyotosis. Too liitle is leucopenia, and is a sign of malnutrition or some disease that
attacks leukocytes.
They have the usual organelles, but no hemoglobin, meaning they are not for oxygen transport.
8. Describe how leukocytes are produced.
You start with a stem cell in the bone marrow, this turns into a myeloid stem cells, then into colony
forming granule cells, and then to all the granular leukocytes. The agranular form via lymphoid stem
cells.
9. Describe the structure and function of platelets.
These serve to cover damaged areas and repair them. They arise from a huge cell called a
megakaryocyte. This will split in the bone marrow to many platelets, which have no nucleus. Very
short life span.
10. Describe the processes of hemostasis. List factors that limit clot formation and prevent undesirable
clotting.
This is the process of the body to stop bleeding. So first say a vessel is damaged: first the vessel will
constrict (called vascular spasm). Then those platelets will adhere to the damaged area to from a plug.
Then finally there will be clotting via certain proteins in the blood. Clotting is called coagulation, and
it’s a huge cascade that will eventually lead to an insoluble clot. Fibrin, another protein in the plasma,
wraps the platelets’ into a mesh
Two pathways are worth noting: An extrinsic, which is simpler. A trauma to the tissue leads to a release
of tissue factor and this will activate factor X. This will cause prothrombin to become thrombin, and
then fibrinogen to fibrin. The intrinsic is slower and eventually leads to factor X activation. So they
both have a common point. Calcium is important for this mechanism.
An undesirable clot is called thrombosis, or a thrombus. The body has a mechanism called fibrinolysis to
dissolve unwanted clots. This is done through the molecule plasmin.
11. Give examples of hemostatic disorders. Indicate the cause of each condition.
Some things that can lead to thrombosis: trauma, infection, atherosclerosis (hardening of the artery). So
you want smooth arteries, good blood flow, and non-sticky platelets.
Tony Berardi
3
If the clot happens to break off the artery and travel in the blood stream, it is now an embolism. If it
occludes blood flow to the carotid (major arteries to the brain) or lungs=BAD.
12. Describe the ABO and Rh blood groups. Explain the basis of transfusion reactions.
These are antigens that are expressed on all RBC that differ is people. “A” bloodtype express the A
antigen, “B” express the B antigen, “AB” express both, and “O” express neither. This is important in
blood transfusions, as an “A” type express anti-B antibodies, “B” type expresses anti-A, “AB” type
expresses none, and “O” type expresses both.
What this means is that if an A type person is given blood from a B type, their immune system will attack
the blood and destroy it, since they have anti-B antibodies. Same with B type; they cannot have A type
blood cause their body will attack it. Since AB express no antibodies, they can have all blood types.
Since O express both anti A and B, they can only receive another O type. So “A” type people can only
have blood from other “A” people and from “O” people (since O has no antigen on the RBC). “B”
people can only receive blood from another “B” and “O” person. So “AB” is called the universal
recipient, as they can receive any blood (since they have no antibodies against any antigen). “O” is the
universal donor, as all types can receive it (since O doesn’t have any antigens, so a reaction is not
possible)
Rh is another protein. (-) means they don’t have it, (+) means they do. Really only important in
pregnancies, because a mother that is (-) might have an (+) baby. This means upon birth, the baby’s
blood will mix with the mothers, so she will create anti-Rh antibodies against the Rh of the baby’s
blood. Then if her second baby is (+), these antibodies can cross the placenta and attack the fetus’
blood; not good. This is called an hemolytic disease of the newborn (HDN)
13. Describe fluids used to replace blood volume and the circumstances for their use.
This is how blood is transferred to another individual when needed. The blood is fractionated to its
respective parts (RBC, WBC, platelets, plasma).
Serum is the plasma without all the clotting shit.
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