Which of these represents the majority of whole blood by volume?
A. plasma
B. leukocytes
C. platelets
D. erythrocytes
answer
A.
Plasma typically constitutes 55% of whole blood, although this value can vary somewhat.
question
What is a hematocrit?
A. Hematocrit is the percentage of erythrocytes in a whole blood sample.
B. Hematocrit is the percentage of plasma in a whole blood sample.
C. Hematocrit is the percentage of leukocytes and platelets in a whole blood sample.
D. Hematocrit is the percentage of all formed elements in a whole blood sample.
answer
A.
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 the formed elements is present in the greatest concentration?
A. granular leukocytes
B. erythrocytes
C. agranular leukocytes
D. platelets
answer
B.
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?
A. Erythrocytes can bend and twist to fit through vessels.
B. Erythrocytes are larger than other cells in the blood.
C. Erythrocytes are nucleated cells.
D. Erythrocytes are cell fragments.
answer
A.
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?
A. antibodies
B. hemoglobin
C. fibrinogen
D. albumin
answer
B.
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?
A. reduced availability of oxygen
B. too many platelets
C. excess oxygen in the bloodstream
D. a high hematocrit
answer
A.
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
Which part of the hemoglobin molecule binds carbon dioxide for transport?
A. heme group
B. spectrin
C. amino acids of the globin
D. iron
answer
C.
The heme groups and iron ions are binding points for oxygen, while carbon dioxide binds to and is carried by the globin polypeptides. The combined form is called carbaminohemoglobin.
question
What part of the body does erythropoietin (EPO) target to increase erythropoiesis?
A. kidneys
B. liver
C. bone marrow
D. lungs
answer
C.
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?
A. reduced tendency for blood to clot
B. decreased blood viscosity
C. a lower hematocrit
D. polycythemia
answer
D.
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
When a person has an acute bacterial infection, such as bacterial meningitis or appendicitis, which type of leukocyte increases in number?
A. eosinophils
B. neutrophils
C. basophils
D. lymphocytes
answer
B.
Neutrophils tend to increase in number in bacterial infections.
question
Which of the following is NOT a functional characteristic of leukocytes?
A. amoeboid motion
B. positive chemotaxis
C. diapedesis
D. leukocytosis
answer
D.
Leukocytosis refers to an excessive number of white blood cells.
question
Which of the following leukocyte is NOT correctly matched with its function?
A. basophils: inflammation
B. eosinophil: bacterial macrophage
C. monocytes: macrophage
D. lymphocytes: immune response against viral infections
answer
B.
Eosinophils play a role in defense against parasites.
question
Which of the following is FALSE regarding the role of platelets in hemostatic reactions?
A. Platelets release chemicals that attract and bind other platelets.
B. Platelets release the only chemical factors that can initiate coagulation.
C. Platelets adhere to exposed collagen fibers.
D. Platelets do not stick to intact endothelial cells.
answer
B.
Platelet chemicals initiate the intrinsic pathway, but tissue factors released from damaged endothelium start the extrinsic pathway for coagulation in motion.
question
Hemostasis is important for __________.
A. stoppage of bleeding
B. red blood cell production
C. white blood cell production
D. red blood cell recycling
answer
A.
Hemostasis leads to stoppage of bleeding. The hemostasis response is fast, localized, and controlled. It involves clotting factors and substances released by damaged tissue and platelets.
question
Which step in hemostasis involves activation of formed elements in the blood?
A. platelet plug formation
B. coagulation
C. fibrin production
D. vascular spasm
answer
A.
Platelets are formed elements that are activated by damaged tissue. Platelets for a temporary plug preventing blood loss.
question
A person who lacks agglutinogen A but has agglutinogen B would have blood type __________.
A. B
B. O
C. A
D. AB
answer
A.
Someone with type B blood only has agglutinogen B on their erythrocytes.
question
During erythroblastosis fetalis, a Rh- mother's anti-Rh antibodies that have crossed the placenta will cause agglutination of the fetus's Rh+ RBCs. However, the reverse problem never happens when a Rh+ mother is pregnant with a Rh- fetus, that is, antibodies produced by the fetus cannot cause agglutination of the mother's Rh+ RBCs. This is true because ______.
A. agglutinins are physically too large to pass across the placenta
B. fetal antibodies are immature and non-functional
C. antibodies that can cause this agglutination are not produced by a fetus
D. the placenta is a barrier that prevents the passage of all antigens
answer
C.
The fetus does not produce antibodies because the immune system is immature.
question
Which ABO blood type is considered to be the universal recipient?
A. O
B. A
C. B
D. AB
answer
D.
Haven't found what you need?
Search for quizzes and test answers now
Quizzes.studymoose.com uses cookies. By continuing you agree to our cookie policy
