Which of these represents the majority of whole blood by volume?
answer
Plasma (Plasma typically constitutes 55% of whole blood, although this value can vary somewhat.)
question
What is a hematocrit?
answer
Hematocrit is the percentage of erythrocytes in a whole blood sample. (Although the percent sign is usually omitted, the hematocrit, which in this figure is 45, is the percentage of erythrocytes in whole blood. The height of the erythrocyte layer is divided by the total height of the material.)
question
Which of these is true of the materials making up the buffy coat in centrifuged blood?
answer
They are intermediate in density between erythrocytes and plasma (Centrifugation separates materials by density. Materials in the buffy coat are intermediate in density between erythrocytes and plasma.)
question
What is the average normal pH range of blood?
answer
7.35-7.45
question
Which of the following is NOT a function of blood?
answer
hormone production (functions are protection, regulation, distribution)
question
Which of the following is NOT a formed element in whole blood?
answer
Albumin. Albumin is a protein that would be found in the plasma. (FE are erythrocytes, leukocytes, platelets)
question
Which of the following plasma proteins is improperly matched with its function?
answer
Gamma globulins: lipid transport. Gamma globulins are also called immunoglobulins and are part of the immune response. (Proper matches are albumin: osmotic pressure, fibrinogen: clotting, alpha globulin: transport of metal ions and fat-soluble vitamins)
question
Albumin definition=
answer
The major contributor to plasma osmotic pressure. and Makes up most of plasma protein.
question
Which plasma constituent is the main contributor to clotting?
answer
Fibrinogen (Fibrinogen comprises 4% of plasma and is an important component in the process
of blood clotting.)
question
Which of the formed elements is present in the greatest concentration?
answer
Erythrocytes (The erythrocytes (red blood cells) make up about 45% of whole blood.)
question
Which of the following is true of the structure of an erythrocyte?
answer
Erythrocytes can bend and twist to fit through vessels. (Erythrocytes are held in shape by
flexible proteins that allow the cell to bend, twist, and cup, but that will return it to its normal
shape. This facilitates the movement of erythrocytes through capillaries that are sometimes
smaller than they are.
question
What is the name of the protein found in erythrocytes that transports respiratory gases?
answer
Hemoglobin (Other than water, hemoglobin makes up almost the entire contents of an
erythrocyte. It can bind both oxygen and carbon dioxide.)
question
What triggers erythropoietin (EPO) production to make new red blood cells?
answer
Reduced availability of oxygen. (Reduced oxygen delivery to the kidneys will result in the
release of erythropoietin (EPO), which in turn promotes the release of more erythrocytes from
the bone marrow.)
question
How many oxygen molecules can be transported by one hemoglobin molecule?
answer
Four (Each Fe2+ ion can bind to a single oxygen molecule.)
question
What is a young, anucleate erythrocyte called?
answer
Reticulocyte (Reticulocytes are a stage in erythrocyte development when the nucleus has just
been lost. These are found in circulating blood, but they are typically only a small percent of total
red cells.)
question
What part of the body does erythropoietin (EPO) target to increase erythropoiesis?
answer
Bone marrow (The bone marrow, specifically red marrow, is the site of blood cell production
and is stimulated by erythropoietin.)
question
Suppose that an individual injects himself with erythropoietin in order to raise his level of
endurance, an act that is usually illegal in competitive sports. Which of the following could
result?
answer
Polycythemia (Erythropoietin causes an increase in release of erythrocytes, which, unless
regulated, can induce polycythemia. EPO increases the hematocrit and the red cell mass and can
lead to increased viscosity of the blood and an increased tendency to form clots.)
question
Mature erythrocytes lack a nucleus.
answer
True
question
Which of the following does NOT stimulate erythrocyte production?
answer
Hyperventilation
question
Higher viscosity of blood will increase the amount of stress placed on the heart while it is
pumping. Viscosity of blood is highest when ________.
answer
Hematocrit is highest
question
People that have a single allele (gene copy) for sickle cell anemia are typically not sick from the
disease and are said to be carriers of sickle cell trait. These people will more often live in the
malaria belt of sub-Saharan Africa. The most likely explanation for this is ________.
answer
People with sickle cell trait have a better chance of surviving malaria
question
Blood reticulocyte counts provide information regarding ________.
answer
Rate of erythrocyte formation
question
What organ in the body regulates erythrocyte production?
answer
Kidney
question
When a person has an acute bacterial infection, such as bacterial meningitis or appendicitis,
which type of leukocyte increases in number?
answer
Neutrophils
question
Which type of leukocyte is responsible for antibody production?
answer
Lymphocytes (B lymphocytes, which mature in the bone marrow and do not require exposure to
thymosin in the thymus as T lymphocytes do, produce antibodies.)
Lymphocytes (Both T and B lymphocytes arise from lymphoid stem cells.)
question
Which cells of the myeloid stem cell pathway have accumulated granules?
answer
Myelocytes (Three of the four pathways leading from myeloid stem cells are myelocytes and
accumulate granules: eosinophilic, basophilic, and neutrophilic.)
question
From which cell do the granulocytes descend?
answer
Myeloblast
question
Which granulated leukocyte is most likely to be active during a bacterial infection?
answer
Neutrophils
question
On a blood smear slide prepared using Wright's stain, you observe a large cell with a U-shaped
nucleus and pale blue cytoplasm. This cell is most likely a(n) __________.
answer
Monocyte
question
Which of the choices below is the parent cell for all formed elements of blood?
answer
Hemocytoblast
question
No visible cytoplasmic granules are present in ________.
answer
Monocytes
question
Which leukocyte might you expect to find in higher quantities in a person experiencing allergies
answer
Eosinophil
question
What factor stimulates platelet formation?
answer
Thrombopoietin
question
Which of the following is FALSE regarding the role of platelets in hemostatic reactions?
answer
Platelets release the only chemical factors that can initiate coagulation. (Platelet chemicals
initiate the intrinsic pathway, but tissue factors released from damaged endothelium start the
extrinsic pathway for coagulation in motion.) (TRUE Platelets do not stick to intact endothelial
cells. Platelets adhere to exposed collagen fibers. Platelets release chemicals that attract and bind
other platelets.)
question
During which event of hemostasis do clotting factors (procoagulants) assist with the
transformation of blood from a liquid to a gel?
answer
The gelling of blood due to formation of insoluble fibrin occurs during the coagulation stage.
question
What "clot buster" enzyme removes unneeded clots after healing has occurred during
fibrinolysis?
answer
Plasmin. (As healing progresses, the clot retraction process reduces the size of the clot, while
plasminogen is activated into plasmin that digests the fibrin in the clot.)
question
Which step in hemostasis involves activation of formed elements in the blood?
answer
Platelet plug formation
question
Which of the following represents a difference between extrinsic and intrinsic blood clotting
pathways?
answer
The extrinsic pathway is faster than the intrinsic pathway.
question
Digesting a clot after it is formed requires activation of what plasma protein by tPA?
answer
Plasminogen
question
Which of the following is not a phase of hemostasis?
