Chapter 6: The Circulatory System

1. In numerical order, the structures indicated by numbers 1 and 8 in Figure 6-1 are the a. aortic arch and the left pulmonary arteries. b. aortic arch and the right pulmonary arteries. c. left pulmonary artery and left pulmonary veins. d. superior vena cava and right pulmonary arteries.

1. Answer: d WHY: Number 1 points to the superior vena cava, the major vein that returns blood to the heart from the upper part of the body. Number 8 points to the right pulmonary arteries that take blood from the heart to the lungs (Fig. 6-7).

100. Hemolytic disease of the newborn is most often caused by a. ABO incompatibility between mother and infant. b. incompatible blood given to the infant in utero. c. previous sensitization of an Rh-negative mother. d. Rh incompatibility between the infant and the father.

100. Answer: c WHY: Hemolytic disease of the newborn (HDN) is most often the result of an Rh-negative mother being sensitized by a previous Rh-positive fetus, causing her to form Rh antibodies. During a subsequent pregnancy, these antibodies can cross the placenta into the fetal circulation, attack the red blood cells of an Rh-positive fetus, and cause hemolysis.

101. A whole-blood specimen consists of a. aggregated blood cells and water. b. blood cells suspended in serum. c. plasma and the formed elements. d. serum and clotted red blood cells.

101. Answer: c WHY: Whole blood, like blood circulating in the bloodstream, consists of liquid called plasma with the formed elements (red blood cells, white blood cells, and platelets) suspended in it. The liquid is called plasma because it still contains fibrinogen and other coagulation factors.

102. The liquid portion of a clotted blood specimen is called a. fibrinogen. b. plasma. c. saline. d. serum.

102. Answer: d WHY: A clotted blood specimen consists of two parts, a clotted portion containing cells enmeshed in fibrin and a liquid portion called serum. The liquid portion is called serum because it does not contain fibrinogen. The fibrinogen was used up in the process of clot formation.

103. A whole-blood specimen has an abnormally large buffy coat. This is an indication that the patient has a. an elevated leukocyte or platelet count. b. an increased amount of red blood cells. c. large numbers of bacteria in the blood. d. recently eaten a meal with a lot of fat.

103. Answer: a WHY: The buffy coat of a whole-blood specimen is made up of white blood cells and platelets. Therefore, a specimen with an abnormally large buffy coat has either a high white blood cell count or a high platelet count.

104. Figure 6-6 shows a centrifuged whole-blood specimen. Identify the portion of the specimen indicated by arrow 1. a. Buffy coat b. Plasma c. Serum d. Red blood cells

104. Answer: b WHY: A whole-blood specimen is collected in an anticoagulant such as EDTA to keep it from clotting. If the specimen is centrifuged or allowed to settle, the clear liquid portion at the top of the specimen is called plasma. Arrow 1 in Figure 6-6 points to the top portion of the specimen, which is the plasma.

105. Identify the portion of the specimen indicated by arrow 2 in Figure 6-6. a. Buffy coat b. Plasma c. Serum d. Red blood cells

105. Answer: a WHY: Arrow 2 in Figure 6-6 points to the thin layer of white blood cells and platelets, commonly called the buffy coat, on top of the red blood cells.

106. How can you visually tell serum from plasma? a. Plasma is yellow, and serum is colorless. b. Serum is clear, and plasma is cloudy. c. Serum is fluid, and plasma is gel-like. d. You cannot visually tell them apart.

106. Answer: d WHY: You cannot visually tell serum from plasma because both serum and plasma are mostly clear, pale yellow fluids. Plasma is sometimes slightly hazy because of the fibrinogen in it, but serum may also be slightly hazy when fats are present, a condition called lipemia.

107. On a blood smear made using Wright stain, the granules of eosinophils stain which color? a. Dark blue b. Lavender c. Orange-pink d. Pink to tan

107. Answer: c WHY: An eosinophil (see Fig. 6-19B) is a type of WBC called a granulocyte because it has granules that are easily visible when viewed on a blood slide stained with a special stain called Wright stain. Eosinophil granules are large and bead-like and stain bright orange-pink.

108. Most tests in which department are performed on plasma specimens? a. Coagulation b. Cytology c. Hematology d. Immunology

108. Answer: a WHY: Coagulation tests are concerned with the blood clotting process, which involves the activation and interaction of a series of components called coagulation factors. Most coagulation tests (except some point-of-care tests that are performed on whole blood) are performed on plasma because it contains coagulation factors. Serum is obtained from clotted blood and cannot be used for most coagulation tests because the coagulation factors are consumed (e.g., fibrinogen) or partially consumed when blood clots.

109. It is preferable to perform most STAT chemistry tests on plasma rather than serum because plasma a. can be tested a lot sooner. b. gives more accurate results. c. is more stable than serum. d. tests require less specimen.

109. Answer: a WHY: A fast turnaround time is vitally important for STAT requests. Serum is ideal for most chemistry tests because nothing has been added to the blood during collection; but to obtain serum, a normal blood specimen must be allowed to clot completely before it can be centrifuged. This can take from 30 to 60 minutes. Blood from patients receiving blood thinners may take even longer. The 30 minutes or more can mean the difference between life and death in a STAT situation. Except for fibrinogen and other coagulation factors, plasma contains the same analytes as serum. However, because a plasma specimen does not clot, it can be spun (centrifuged) immediately upon reaching the laboratory and therefore tested much sooner.

110. Which is the abbreviation for a test that is always performed on whole blood? a. BUN b. CBC c. LDL d. PTT

110. Answer: b WHY: A complete blood count (CBC) is a multipart test that includes erythrocyte, leukocyte, and platelet counts. It is always performed on whole blood because the cells cannot be identified or counted in blood that is clotted. A blood urea nitrogen (BUN) and lactate dehydrogenase (LDL) are chemistry tests that are typically performed on serum. A PTT test is a coagulation test performed on plasma because it contains clotting factors. A PTT can also be performed on whole blood from a fingerstick using a special machine.

111. Which is the abbreviation for a test that can be done on plasma? a. CBC b. ESR c. Hgb d. PTT

111. Answer: d WHY: A partial thromboplastin test (PTT) is a coagulation test performed on plasma because plasma contains clotting factors. A PTT can also be performed on whole blood from a fingerstick using a special machine. A CBC, erythrocyte sedimentation rate (ESR), and hemoglobin (Hgb) are hematology tests that require a whole-blood EDTA specimen.

112. Serum a. can be used for most hematology tests. b. contains the clotting factor fibrinogen. c. is collected in a nonanticoagulant tube. d. normally has a very deep yellow color.

112. Answer: c WHY: To obtain serum, blood must be allowed to clot. Consequently, serum specimens are collected in tubes that do not contain an anticoagulant. During the clotting process, fibrinogen is split into fibrin, which enmeshes the cells to form the clot. Once the clotting is complete, the specimen is centrifuged; the normally clear, pale yellow liquid obtained is called serum. Serum does not contain fibrinogen because it was used up in the clotting process. Most hematology tests are performed on whole-blood specimens collected in EDTA tubes, not on serum.

113. A person with thrombocytosis has abnormally a. decreased platelets. b. functioning platelets. c. increased platelets. d. large platelets.

113. Answer: c WHY: "Thromb," "cyt," and "osis" mean "clotting," "cell," and "condition," respectively. Thrombocytosis is a condition in which the clotting cells (platelets) are abnormally increased.

114. A disease that is often characterized by an abnormally low red blood cell count is called a. anemia. b. leukemia. c. neutropenia. d. polycythemia.

114. Answer: a WHY: Anemia is a blood disorder usually characterized by an abnormal reduction in the number of red blood cells in the circulating blood. Leukemia is a disorder characterized by an abnormal increase in white blood cell (WBC) numbers along with an increase in abnormal forms of WBCs. Polycythemia is overproduction of red blood cells. Thrombocytopenia is abnormally decreased platelets.

115. Which of the following is the abbreviation for a test of the formed elements? a. ASO b. CBC c. Lytes d. SPEP

115. Answer: b WHY: The formed elements are red blood cells, white blood cells, and platelets. Assessing the formed elements is part of a hematology test called a complete blood count (CBC). The antistreptolysin (ASO) test checks for the antibody against streptolysin O, a red blood cell-destroying substance produced by a certain type of streptococcus. Electrolytes ("lytes") is a panel of chemistry tests that measure ions in the blood, most commonly sodium, potassium, chloride, and bicarbonate. Serum protein electrophoresis (SPEP) is a chemistry test that identifies various protein components in a serum specimen.

116. An abnormal increase in white blood cells is called a. leukemia. b. leukocytosis. c. leukopenia. d. leukopoiesis.

116. Answer: b WHY: When broken into parts, "leuko-cyt-osis" means "white cell condition." The term is used to describe an abnormal increase of white blood cells. Leukemia is a disorder characterized by an abnormal increase in WBC numbers along with an increase in abnormal WBC forms. Leukopenia is an abnormal decrease in WBC numbers. Leukopoiesis is leukocyte production.

117. Which of the following is a diagnostic test for blood cell disorders? a. Bilirubin b. Creatinine c. Ferritin d. Glucose

117. Answer: c WHY: Ferritin, the form in which iron is stored in the tissues, is a whole-blood chemistry test that is also used in the diagnosis of blood disorders. Creatinine is a kidney function test performed in the chemistry department. Bilirubin is a chemistry test used to diagnose or monitor liver function. Glucose is a chemistry test used in the diagnosis of diabetes, hypoglycemia, and other disorders of carbohydrate metabolism.

118. The coagulation process plays a role in a. hemolysis. b. hemopoiesis. c. hemostasis. d. homeostasis.

118. Answer: c WHY: Hemostasis means "stopping or controlling the flow of blood." Coagulation plays a major role in hemostasis. Hemolysis is the destruction of red blood cells. Hemopoiesis is the production and maturation of red blood cells. Homeostasis is the state of equilibrium or balance the body strives to maintain.

119. The ability of platelets to stick to each other is called platelet a. aggregation. b. adhesion. c. cohesion. d. inhibition.

119. Answer: a WHY: "Platelet aggregation" is the term used to describe the ability of platelets to stick to each other. Platelet adhesion is the ability of platelets to stick to surfaces. The property of adhering is called cohesion. Inhibition is the stopping or suppression of a function.

120. Which ion is essential to the coagulation process? a. Calcium b. Chloride c. Potassium d. Sodium

120. Answer: a WHY: Ions are particles that carry an electrical charge. The coagulation process requires the presence of calcium ions, which have a positive charge, for proper function. Chloride, sodium, and potassium are also ions. They function in other body processes, however.

121. The extrinsic or contact activation coagulation pathway is initiated by a. activation of plasma coagulation factors. b. commencement of platelet aggregation. c. tissue factor released from injured tissue. d. events occurring within the bloodstream.

121. Answer: c WHY: The word "extrinsic" means "originating outside." The extrinsic/contact activation coagulation pathway is initiated by cell-based tissue factor (TF). TF is normally outside the bloodstream but is exposed to the blood during tissue injury. Platelet aggregation is part of platelet plug formation, which occurs because of TF initiation of the coagulation process.

122. The first response in the hemostatic process is a. fibrin formation. b. platelet adhesion c. thrombin creation. d. vasoconstriction.

122. Answer: d WHY: The first response in the hemostatic process (Fig. 6-25) is the constriction of blood vessels (vasoconstriction) to slow down blood loss. Platelet adhesion, thrombin generation, and the conversion of fibrinogen to fibrin occur during the second response, which is platelet plug formation. Thrombin generation and fibrin formation also take place during the third response, which is hemostatic plug formation. The fourth response is fibrinolysis, the process that dissolves (i.e., degrades) the fibrin clot after the site heals.

123. Platelet plug formation takes place in which phase of the coagulation process? a. Amplification b. Initiation c. Propagation d. Termination

123. Answer: b WHY: Platelet adhesion and aggregation take place in the initiation phase of the coagulation process, which results in the formation of the platelet plug. The amplification and propagation phases involve the formation of the stable blood clot called the hemostatic plug. Termination of coagulation is the end result of the propagation phase and also the work of natural inhibitors.

125. A disorder caused most often by lack of factor VIII is a. hemophilia. b. intravascular coagulation. c. thrombocytopenia. d. varicose veins.

125. Answer: a WHY: Hemophilia is a hereditary blood disorder characterized by very long bleeding times. The most common type of hemophilia is caused by the lack of clotting factor VIII. Disseminated intravascular coagulation (DIC) is a pathologic form of diffuse rather than local coagulation in which coagulation factors are consumed to such an extent that bleeding occurs. Thrombocytopenia is an abnormally decreased number of platelets. Varicose veins—swollen, knotted veins—are not a coagulation disorder.

126. Coagulation problems may result from liver disease because the liver a. filters impurities from the blood. b. manufactures coagulation factors. c. removes damaged red blood cells. d. stores and releases calcium ions.

126. Answer: b WHY: The liver plays a major role in coagulation. It manufactures the clotting factors fibrinogen and prothrombin and is the source of heparin, a naturally formed anticoagulant found in the bloodstream.

127. Which of the following is an enzyme that plays the major role in coagulation? a. Fibrin b. Heparin c. Plasmin d. Thrombin

127. Answer: d WHY: Thrombin functions throughout the coagulation process. Its major role is to convert fibrinogen to soluble fibrin, but it also intensifies coagulation, supports platelet plug formation, activates protein C to stop its formation, and initiates the breakdown of the fibrin clot by its role in plasmin production. Plasmin is an enzyme that causes clot lysis in the last hemostatic response to injury, fibrinolysis. Heparin is a natural anticoagulant. Fibrin is an elastic, threadlike protein that reinforces the platelet plug and the blood clot.

128. The coagulation process is kept in check by a. fibrin degradation. b. natural inhibitors. c. plasminogen enzymes. d. prothrombin activators.

128. Answer: b WHY: Substances called natural inhibitors circulate in the plasma along with the coagulation factors. They normally keep the coagulation process in check and limited to local sites by binding with activated coagulation factors that escape the clotting site.

129. Which test is used to monitor coumarin therapy? a. CBC b. DIC c. PTT d. PT

129. Answer: d WHY: The protime (PT) test evaluates extrinsic pathway function and is used to monitor coumarin therapy. A complete blood count (CBC) is a hematology test that evaluates the formed elements. DIC stands for disseminated intravascular coagulation, which is evaluated with a test called a DIC screen. The test for the activated partial thromboplastin time (APTT or PTT) evaluates the intrinsic coagulation pathway and is used to monitor heparin therapy.

130. A needle puncture to a vein is normally healed by a. activation of factor VIII. b. blood clot formation. c. platelet plug formation. d. vasoconstriction.

130. Answer: c WHY: For some injuries such as a needle puncture to a vein, platelet plug formation in the initiation phase of the coagulation process is enough to seal the site until healing occurs, in which case the coagulation process goes no further. For larger injuries, the process continues to hemostatic plug (blood clot) formation, which involves activation of a series of coagulation factors (including factor VIII). Vasoconstriction plays a role in reducing blood flow in the immediate area of injury to prevent blood from escaping the vessel but by itself is not enough to seal an injury.

131. Obstruction of a blood vessel by an embolus a. causes vessel necrosis. b. is called an embolism. c. leads to an aneurysm. d. produces atherosclerosis.

131. Answer: b WHY: A circulating blood clot, part of a clot, or other mass of undissolved matter is called an embolus. The sudden obstruction of a blood vessel by an embolus is called an embolism.

132. Which of the following is a coagulation test? a. Digoxin b. Hemogram c. Myoglobin d. Protime

132. Answer: d WHY: A protime (PT), also called a prothrombin time, is a coagulation test. Digoxin is a chemistry test for a drug of the same name that is used in patients with certain heart problems. A hemogram is a type of hematology report that lists the results of a complete blood count. Myoglobin is an oxygen-binding protein found in cardiac and skeletal muscle.

135. Lymph fluid keeps moving in the right direction because of a. functioning of the lymphatic ducts. b. lymphatic capillary structure. c. pressure from the arterial system. d. valves within the lymph vessels.

135. Answer: d WHY: Lymph fluid (lymph) moves through lymph vessels primarily by skeletal muscle contraction, much as blood moves through the veins. Like veins, the lymph vessels have valves to keep the lymph flowing in the right direction.

137. Lymph node tissue can a. create red blood cells. b. produce tissue fluid. c. remove impurities. d. secrete antibodies.

137. Answer: c WHY: Lymph node tissue (lymphoid tissue) is a special kind of tissue that can trap microorganisms, remove impurities, and process lymphocytes. It does not have the ability to create red blood cells, produce tissue fluid, or secrete antibodies.

139. A malignant lymphoid tumor is called a. lymphadenopathy. b. lymphangitis. c. lymphoma. d. lymphoma.

139. Answer: d WHY: "Lymphoma" is the medical term for a tumor of lymphoid tissue that is often malignant. The term is derived from "lymph" which means lymphoid or originating from lymphocytes, and "oma" which means tumor.

140. Which test is associated with the lymph system? a. Carotene b. Cholinesterase c. Lipoprotein d. Mononucleosis

140. Answer: d WHY: Mononucleosis is an acute infectious disease that primarily affects lymphoid tissue. The mononucleosis (mono) test is the most common test associated with the lymphatic system.

47. The tunica adventitia is the a. external layer of a blood vessel. b. inside lining of a blood vessel. c. internal layer of a blood vessel. d. middle layer of a blood vessel.

47. Answer: a WHY: Blood vessels have three main layers (Fig. 6-13). The tunica adventitia (also called the tunica externa) is the outer layer of an artery or a vein. It is made up of connective tissue and is thicker in arteries than veins. The tunica intima (also called tunica interna) is the inner layer or lining of a blood vessel; it is composed of a single layer of endothelial cells with an underlying basement membrane, a connective tissue layer, and an elastic membrane. The tunica media is the middle layer, composed of smooth muscle and some elastic fibers. The tunica media is much thicker in arteries than in veins.

48. The internal space of a blood vessel is called the a. interna. b. intima. c. lumen. d. media.

48. Answer: c WHY: "Lumen" is the term for the space within a hollow tubular structure such as a blood vessel, intestine, or blood collection needle. "Intima," "interna," and "media" are terms used in identifying blood vessel layers. The tunica intima (also called the tunica interna) is the inner layer of a blood vessel. The tunica media is the middle layer of a blood vessel.

49. The layers of arteries differ from the layers of veins in that the a. inner lining is much thicker in veins. b. middle layer of veins is more elastic. c. muscle layer is thicker in arteries. d. outer layer of arteries is thinner.

49. Answer: c WHY: The smooth muscle of the tunica media (middle layer) is much thicker in arteries than in veins (see Fig. 6-13). The tunica adventitia, or outer layer, is also thicker in arteries. Both veins and arteries are lined with a single layer of endothelial cells. Arteries typically have more elastic tissue than veins.

50. Oxygen and nutrients diffuse through the walls of the a. alveoli. b. arterioles. c. capillaries. d. venules.

50. Answer: c WHY: Capillaries (see Fig. 6-13) are the smallest blood vessels. They are one-cell thick, which allows the exchange of oxygen, carbon dioxide, nutrients, and wastes between the tissue cells and the blood to take place through their walls. Alveoli are thin-walled, saclike chambers within the lungs, where oxygen and carbon dioxide are exchanged between the air and the blood. Arterioles are tiny arteries that connect with and deliver blood to the capillaries. Venules are tiny veins at the junction where the capillaries merge with the venous circulation.

51. Identify the structure on the right in Figure 6-2 from the following choices. a. Artery b. Capillary c. Lymph vessel d. Vein

51. Answer: d WHY: Figure 6-2 is a cross-section of an artery and a vein (Fig. 6-14). The structure on the right is a vein. If you look closely, you can see the valve against the wall on the left. Arteries do not have valves. Also, the structure on the left has a very thick middle layer, which is characteristic of an artery. See Figure 6-13 for a comparison diagram of artery, vein, and capillary structure.

6. The heart is surrounded by a thin fluid-filled sac called the a. endocardium. b. epicardium. c. myocardium. d. pericardium.

6. Answer: d WHY: The pericardium is a double-layered sac enclosing the heart. The space between the layers is filled with fluid, which reduces friction as the heart beats. The endocardium is a thin membrane lining the inside of the heart. The epicardium is the thin outer layer of the heart. The myocardium is the thick muscular middle layer of the heart.

98. A woman who becomes "sensitized" to the Rh factor a. can produce antibodies against the Rh antigen. b. has Rh antigen circulating in her bloodstream. c. should not try to have more than one child. d. will test Rh-positive for months afterward.

98. Answer: a WHY: Becoming sensitized means that the individual may produce antibodies against the Rh factor. Rh antibodies produced by the mother and circulating in her bloodstream can cross the placenta into the fetal circulation and cause the agglutination (Fig. 6-24) and destruction of red blood cells in an Rh-positive fetus.

99. A person who has A-negative blood has red blood cells that a. have the A antigen and lack the Rh antigen. b. have both the A antigen and the Rh antigen. c. lack the A antigen and have the Rh antigen. d. lack both the A antigen and the Rh antigen.

99. Answer: a WHY: The red blood cells of an individual whose blood type is A-negative have the A antigen but lack the Rh antigen. (See the answer to question 96.)

138. Lymphoid tissue is also found in the a. heart. b. kidneys. c. lungs. d. thymus.

138. Answer: d WHY: Lymphoid tissue is also found in other areas of the body, including the thymus, tonsils, gastrointestinal tract, and spleen. It is not found in the heart, lungs, or kidneys.

28. The average normal heart rate is a. 63 bpm. b. 72 bpm. c. 81 bpm. d. 96 bpm.

28. Answer: b WHY: The heart rate is the number of beats per minute (bpm). Average normal heart rate is around 72 bpm.

133. Lymph fluid is most like a. serum. b. plasma. c. urine. d. whole blood.

133. Answer: b WHY: Lymph fluid is similar to plasma but is 95% water instead of 91%. Plasma is unlike serum because it contains fibrinogen and serum does not. The composition of lymph fluid is very different from the composition of whole blood and urine.

134. Lymph fluid originates from excess a. blood plasma. b. digestive liquid. c. tissue fluid. d. urinary filtrate.

134. Answer: c WHY: Body cells are bathed in tissue fluid acquired from the bloodstream. Much of the fluid diffuses back into the capillaries along with waste products of metabolism. Excess tissue fluid filters into lymphatic capillaries, where it is called lymph.

11. The semilunar valves are located a. at the exits of both of the ventricles. b. between the atria and the ventricles. c. where the aortic arch becomes the aorta. d. within the veins of the systemic system.

11. Answer: a WHY: The valves at the exits of the ventricles (see Fig. 6-7) are called semilunar valves because each flap resembles a half-moon. The pulmonary semilunar valve is located at the exit of the right ventricle and the aortic semilunar valve is located at the exit of the left ventricle. There is no valve between the aortic arch and the aorta. The valves in the veins of the systemic system are similar to semilunar valves but are not called semilunar valves.

18. The medical term for a heart attack is myocardial a. arrhythmia. b. infarction. c. ischemia. d. tachycardia.

18. Answer: b WHY: A heart attack is the death of heart muscle from lack of oxygen. The medical term for this is myocardial infarction (MI). ("Myocardial" means "pertaining to the heart muscle." "Infarction" means "death of tissue resulting from oxygen deprivation.") MI can be caused by complete obstruction of a coronary artery or prolonged ischemia (see the answer to question 17). Arrhythmia is an irregularity in the heart rate, rhythm, or beat. "Tachycardia" is the term for a fast heart rate of more than 100 bpm.

19. The heart's "pacemaker" is the a. bundle of His. b. chorda tendinea. c. papillary muscle. d. sinoatrial node.

19. Answer: d WHY: Heart contraction is initiated by an electrical impulse generated by the sinoatrial (SA) node, located in the upper wall of the right atrium (see Fig. 6-8). It is called the pacemaker because it influences the rhythm and rate of the heartbeat. The bundle of His is part of the relay system that spreads the electrical impulse throughout the heart muscle. "Chorda tendinea" (pl., chordae tendineae) is the name for the thin thread of tissue that keeps an atrioventricular valve from flipping back into the atrium. A papillary muscle is attached to a chorda tendinea and helps open and close it.

2. In numerical order, the structures indicated by numbers 11 and 17 in Figure 6-1 are the a. left pulmonary arteries and right pulmonary veins. b. left pulmonary veins and the arch of the aorta. c. right pulmonary arteries and superior vena cava. d. right pulmonary veins and inferior vena cava.

2. Answer: b WHY: Number 11 points to the left pulmonary veins, which carry oxygen-rich blood from the lungs back to the left atrium of the heart. Number 17 points to the aortic arch, through which oxygenated blood travels from the heart to the systemic system (see Fig. 6-7).

23. A cardiac cycle lasts approximately a. 0.5 seconds. b. 0.8 seconds. c. 1.5 seconds. d. 8.0 seconds.

23. Answer: b WHY: The complete cardiac cycle—involving the simultaneous contraction of both atria pushing the blood into the ventricles, followed by the simultaneous contraction of the ventricles pushing the blood into the exit arteries, and then the relaxation of both—takes approximately 0.8 seconds.

24. On an electrocardiogram, atrial activity is represented by the a. P wave. b. QRS complex. c. T wave. d. T and P waves.

24. Answer: a WHY: The P wave on an electrocardiogram tracing (see Fig. 6-9) represents the activity of the atria and is usually the first wave seen. The QRS complex (a collection of three waves) along with the T wave represents the activity of ventricles.

26. The first sound of the heartbeat is created by the a. closing of the atrioventricular valves. b. opening of the semilunar valves. c. resonation of the chordae tendineae. d. ventricular muscle contraction echo.

26. Answer: a WHY: The closing of the atrioventricular valves as the ventricles contract results in the first sound of the heartbeat, which is a long, low-pitched sound described as a "lubb." The second sound of the heartbeat comes from the closing of the semilunar valves and is a shorter, sharper sound described as a "dupp."

27. Abnormal heart sounds are called a. arrhythmias. b. extrasystoles. c. fibrillations. d. murmurs.

27. Answer: d WHY: Murmurs are abnormal heart sounds, usually caused by faulty valve action. Arrhythmias, extrasystoles, and fibrillations are abnormal contractions, not sounds.

29. An abnormally fast heart rate is called a. bradycardia. b. extrasystole. c. fibrillation. d. tachycardia.

29. Answer: d WHY: Tachycardia is an abnormally fast rate. Bradycardia is an abnormally slow rate. An extrasystole is an extra beat before the normal beat. Fibrillation is the term for rapid, uncoordinated contractions.

30. A person's pulse is created by a wave of pressure caused by a. atrial contraction. b. atrial relaxation. c. ventricular contraction. d. ventricular relaxation.

30. Answer: c WHY: The wave of pressure created as the ventricles contract and blood is forced out of the heart and through the arteries creates the throbbing beat known as the pulse.

31. The force exerted by the blood on the walls of the blood vessels is called a. blood pressure. b. cardiac output. c. heart rhythm. d. pulse rate.

31. Answer: a WHY: Blood pressure is defined as the force (pressure) exerted by the blood on the walls of the blood vessels. Cardiac output is the volume of blood pumped by the heart in 1 minute. Heart rhythm is the regularity of heart action or function. Pulse rate is the number of pulses per minute and normally reflects the heart rate, or number of heart beats per minute.

32. The technical term for which device is "sphygmomanometer"? a. Artificial pacemaker b. Brain wave detector c. Blood pressure cuff d. Heart wave monitor

32. Answer: c WHY: "Sphygmomanometer" is the technical term for a blood pressure cuff. An artificial pacemaker is an implanted electrical device that automatically generates electrical impulses to initiate the heartbeat. A machine that records brain waves is used in electroencephalography (EEG). An electrocardiogram (ECG) is a record (tracing) of the electrical currents or waves that correspond to muscle contractions of the heart.

33. Which of the following is a normal blood pressure reading? a. 60/90 mm Hg b. 80/120 mm Hg c. 100/120 mm Hg d. 118/79 mm Hg

33. Answer: d WHY: Blood pressure is a measure of the pressure exerted on the walls of a blood vessel. It is commonly measured in a large artery such as the brachial. Blood pressure is expressed in millimeters of mercury and has two components: the systolic pressure, which is the highest pressure reached during ventricular contraction, and the diastolic pressure, which occurs during relaxation of the ventricles. The American Heart Association defines normal blood pressure for the relaxed, sitting adult as a systolic pressure of less than 120 mm Hg and a diastolic pressure of less than 80 mm Hg.

34. Systolic pressure measures pressure in the arteries during a. atrial contraction. b. atrial relaxation. c. ventricular contraction. d. ventricular relaxation.

34. Answer: c WHY: Systolic pressure is the pressure in the arteries during contraction of the ventricles. Diastolic pressure is the arterial pressure when the ventricles are relaxed. Because atrial contraction is so very close to ventricular contraction, blood pressure during atrial contraction and relaxation cannot easily be detected and is not normally measured.

35. An infection of the lining of the heart is called a. angina pectoris. b. aortic stenosis. c. endocarditis. d. pericarditis.

35. Answer: c WHY: Endocarditis means "inflammation of the endocardium." The endocardium is the thin membrane lining the inner surface of the heart. Angina pectoris refers to chest pain usually caused by decreased blood flow to the muscle layer of the heart. "Aortic stenosis" is the term used to describe a narrowing of the aorta or its opening. Pericarditis is inflammation of the pericardium, the thin, fluid-filled sac surrounding the heart.

36. Which of the following are abbreviations for cardiac enzyme tests? a. ALP, ALT b. BUN, PT c. CK, LDH d. GTT, ESR

36. Answer: c WHY: Creatine kinase (CK) and lactate dehydrogenase (LDH) are enzymes present in cardiac muscle. They are released during myocardial infarction. Alkaline phosphatase (ALP) and alanine aminotransferase (ALT) are enzymes measured most commonly to determine liver function. Blood urea nitrogen (BUN) is a kidney function test, and prothrombin time (PT) is a coagulation test used to monitor anticoagulant therapy. A glucose tolerance test (GTT) measures glucose metabolism, and the erythrocyte sedimentation rate (ESR) is a nonspecific indicator of disease, especially inflammatory conditions such as arthritis.

37. The pulmonary circulation takes blood to the a. arteries in the heart muscle. b. heart from the body tissues. c. internal organs to the body. d. lungs and back to the heart.

37. Answer: d WHY: Pulmonary circulation carries deoxygenated blood from the right ventricle of the heart to the lungs via the pulmonary artery. It also returns oxygenated blood from the lungs to the left atrium of the heart via the pulmonary vein. The left ventricle pumps the oxygenated blood into the arterial systemic circulation via the aorta. The arterial systemic circulation delivers the blood to the tissues. The venous systemic circulation returns deoxygenated blood to the heart (see Figs. 6-7 and 6-10).

39. Blood vessels that carry blood away from the heart are called a. arteries. b. capillaries. c. veins. d. venules.

39. Answer: a WHY: Arteries are vessels that carry blood away from the heart. (A way to remember this is to think "AA" for "arteries away.") Veins, such as the vena cava, carry blood to the heart. Capillaries are vessels that connect the ends of the smallest arteries (arterioles) to the smallest veins (venules).

44. What keeps the blood moving through the venous system? a. Expansion and contraction of the systemic arteries b. Movement of fluid throughout the lymphatic system c. Pressure caused by contraction of the ventricles d. Skeletal muscle movement and valves in the veins

44. Answer: d WHY: Unlike the arteries, veins do not have sufficient pressure from the heart's contractions to keep the blood moving through them. Veins rely on movement of nearby skeletal muscles and the opening and closing of the valves within them to keep the blood moving toward the heart (Fig. 6-12). The presence of valves in veins but not arteries is a major structural difference between the arteries and veins.

45. The smallest branches of veins are called a. arterioles. b. capillaries. c. lumina. d. venules.

45. Answer: d WHY: "Venules" is the medical term for the smallest veins. The medical term for the smallest arteries is "arterioles." Capillaries connect the arterioles (which are the end of the arterial system) to the venules (which are the beginning of venous system). "Lumen" (pl., lumina) is the term for the internal space of any tubular vessel.

46. Which are tiny blood vessels that are only one-cell thick? a. Arteries b. Arterioles c. Capillaries d. Venules

46. Answer: c WHY: Capillaries are tiny blood vessels that form the fine network that delivers oxygen and nutrients to the tissues and carries carbon dioxide and other waste products away. They are only one-cell thick, which allows gases and nutrients to diffuse through their walls. Arteries, arterioles, and venules have multiple layers and are many cells thick.

52. The right ventricle delivers blood to the a. aortic arch. b. left atrium. c. pulmonary artery. d. pulmonary vein.

52. Answer: c WHY: The right ventricle delivers blood to the pulmonary artery, which takes it to the lungs to pick up oxygen. The left ventricle delivers blood to the aorta by way of the aortic arch. The pulmonary veins carry oxygenated blood from the lungs to the left atrium of the heart (see Fig. 6-10).

53. Which of the following blood vessels carries oxygenated blood? a. Brachial vein b. Pulmonary vein c. Pulmonary artery d. Inferior vena cava

53. Answer: b WHY: The pulmonary vein, part of the pulmonary circulation, carries oxygenated blood from the lungs to the heart so that it can be delivered to the systemic circulation. The inferior vena cava delivers deoxygenated blood from the systemic venous circulation to the lower right atrium of the heart. The brachial vein is part of the systemic venous circulation carrying deoxygenated blood. The pulmonary artery carries deoxygenated blood from the heart to the lungs.

54. Which of the following blood vessels are listed in the proper direction of blood flow? a. Arteries, arterioles, capillaries b. Arterioles, venules, capillaries c. Capillaries, arterioles, arteries d. Veins, venules, capillaries

54. Answer: a WHY: Blood flows from the heart into the arteries which branch into smaller and smaller arteries, the smallest of which are called arterioles. Arterioles connect to the capillaries. Capillaries form the bridge between the arterial and venous circulation and are where the exchange of gases, nutrients, and waste products takes place. The opposite ends of the capillaries connect to the smallest veins, which are called venules. Venules merge with larger and larger veins until the blood returns to the heart.

55. The antecubital (AC) fossa is located a. anterior to the elbow. b. distal to the wrist. c. medial to the elbow. d. posterior to the wrist.

55. Answer: a WHY: The antecubital fossa is the area of the arm located in front of (anterior to) the elbow.

56. The basilic vein is the last choice for venipuncture because it is a. deeply buried in the AC fossa. b. fixed in the surrounding tissue. c. located close to a major nerve. d. the hardest AC vein to palpate

56. Answer: c WHY: The basilic vein (Fig. 6-15) is normally large, superficial, and easy to palpate. However, it is not well anchored within the surrounding tissue. This causes it to roll easily, increasing the possibility of accidental puncture of the median nerve or the brachial artery located close to it and is the major reason it is the last choice for venipuncture.

57. In numerical order, the veins identified by numbers 1, 2, and 3 in Figure 6-3 are the a. basilic, median cubital, and cephalic. b. cephalic, basilic, and median cubital. c. median cubital, cephalic, and basilic. d. subclavian, median cubital, and basilic.

57. Answer: b WHY: The vein identified by number 1 is the cephalic vein. The vein identified by number 2 is the basilic vein. The vein identified by number 3 is the median cubital vein. (See the H-pattern veins in Fig. 6-15.)

60. Which of the following veins is found only in or below the antecubital fossa? a. Basilic b. Cephalic c. Median d. Subclavian

60. Answer: c WHY: The median vein (see Fig. 6-16) can be found in and below the antecubital (AC) fossa only. Although the basilic, cephalic, and subclavian veins in the arm can be found below the AC crease, they are also prominent in the upper arm.

61. Which major vein merges with the brachiocephalic vein in the chest? a. Cephalic b. Popliteal c. Saphenous d. Subclavian

61. Answer: d WHY: The subclavian vein is in the shoulder area of the arm (see Figs. 6-15 refer to #57 and 6-16 refer to #60) and merges with the brachiocephalic vein in the chest (Fig. 6-18). The cephalic vein merges with the subclavian vein. The popliteal and saphenous veins are in the leg (see Fig. 6-11).

62. Two medial cutaneous nerves lie close to which vein? a. Basilic b. Cephalic c. Median d. Radial

62. Answer: a WHY: Both the anterior and posterior medial cutaneous nerves are very close to the basilic vein and are a major reason this vein is the very last choice for venipuncture (see Figs. 6-15 refer to #57 and 6-16refer to #60).

63. Which of the following veins are listed in the proper order of selection for venipuncture? a. Basilic, cephalic, median cubital b. Cephalic, median cubital, basilic c. Median, median basilic, cephalic d. Median cubital, cephalic, basilic

63. Answer: d WHY: The median cubital, cephalic, and basilic are in the correct order of selection for veins in the H pattern. In choosing the best vein in the H pattern, the first selection is the median cubital because it is large and well anchored and therefore does not bruise easily and is least painful to puncture. The cephalic vein is the next choice because it is fairly well anchored and less painful to puncture than the basilic. The basilic vein is the last choice because it rolls and bruises easily, is more painful to puncture, and there is the possibility of accidentally hitting the brachial artery and a major nerve when accessing it (see Figs. 6-15 refer to #57 and 6-16 refer to #60). According to the CLSI, the basilic vein should not be selected unless the other veins on both arms have been eliminated. The median basilic is an M-pattern vein.

64. When the hand is prone, the antecubital portion of the cephalic vein is normally located in line with the a. index finger. b. little finger. c. radial artery. d. thumb.

64. Answer: b WHY: When the hand is prone, the palm faces downward, causing the antecubital portion of the cephalic vein to be in line with the little finger. When the arm is in the normal anatomical position, the palm is up and the cephalic vein is on the same side as the thumb.

65. According to the Clinical and Laboratory Standards Institute (CLSI), venipuncture should not be performed on leg, ankle, or foot veins unless a. both arms have IVs or other intravascular devices. b. permission of the patient's physician has been obtained. c. there are no acceptable antecubital or hand veins. d. the patient does not have any coagulation problems.

65. Answer: b WHY: Leg, ankle, and foot veins should never be punctured routinely. Serious problems can result if ankle or foot veins of patients with coagulation problems or poor circulation are used for venipuncture. Test results can also be affected. If no other sites are available, the patient's physician must be consulted and permission obtained before performing venipuncture on a leg, ankle, or foot vein of any patient.

66. The popliteal vein is found in the a. arm. b. hand. c. heart. d. leg.

66. Answer: d WHY: The popliteal vein is located deep in the leg (see Fig. 6-11) in the area behind the knee. It is a continuation of the femoral vein.

67. This is the medical term for a blood clot circulating in the bloodstream. a. Aneurysm b. Embolism c. Embolus d. Thrombus

67. Answer: c WHY: "Embolus" is the medical term for a blood clot or other undissolved matter circulating in the bloodstream. An aneurysm is a bulging or dilation of a blood vessel. An embolism is the obstruction of a blood vessel by an embolus. A thrombus is a stationary blood clot that obstructs or partially obstructs a blood vessel.

68. The medical term for vein inflammation is a. embolism. b. hemostasis. c. phlebitis. d. thrombosis.

68. Answer: c WHY: Phlebitis is the medical term for inflammation of a vein. The term comes from the word root "phleb" for "vein," and the suffix "-itis" for "inflammation." An embolism is the obstruction of a blood vessel by a blood clot or other undissolved foreign matter. Hemostasis is the process of stopping bleeding. Thrombosis is the formation or existence of a blood clot in the vascular system.

70. Lipid accumulation on the intima of an artery is called a. atherosclerosis. b. cholesterol. c. endocarditis. d. lipemia.

70. Answer: a WHY: Atherosclerosis is a form of arteriosclerosis involving changes in the intima of the artery caused by the accumulation of lipid, cholesterol, and calcium material. Cholesterol is a substance produced by the liver; it is also found in animal products such as meat and eggs. It is an essential part of lipid metabolism, but high blood levels increase the risk of developing atherosclerosis. Endocarditis is inflammation of the membrane that lines the inside of the heart. Lipemia is a condition in which there is an abnormal amount of fat in the blood.

71. Which of the following is a localized dilation or bulging of an artery? a. Aneurysm b. Embolism c. Phlebitis d. Thrombus

71. Answer: a WHY: "Aneurysm" is a medical term for a localized dilation or bulging of a blood vessel, usually an artery. An embolism is the obstruction of a blood vessel by a blood clot or other undissolved foreign matter. Arteriosclerosis is a hardening or thickening and loss of elasticity of the wall of the artery. Thrombophlebitis is defined as inflammation of the vein in conjunction with the formation of a blood clot.

72. Inflammation of a vein in conjunction with formation of a blood clot is called a. atherosclerosis. b. phlebosclerosis. c. thrombophlebitis. d. vasculitis.

72. Answer: c WHY: The word root "thromb" means "clot." Phlebitis is inflammation of a vein. The meaning of thrombophlebitis is "inflammation of a vein in conjunction with the formation of a blood clot." Atherosclerosis is a form of arteriosclerosis involving changes in the intima of the artery. Phlebosclerosis is the fibrous hardening of vein walls. "Vasculitis" is a general term meaning "inflammation of blood vessels."

74. The normal composition of blood is approximately a. 10% plasma, 90% formed elements. b. 30% plasma, 70% formed elements. c. 55% plasma, 45% formed elements. d. 91% plasma, 9% formed elements.

74. Answer: c WHY: The normal ratio of plasma to formed elements is approximately 55% plasma and 45% cells. This means that approximately half of a normal blood specimen is serum (in a clot tube) or plasma (in an anticoagulant tube), which is important in determining how much blood to collect for testing purposes.

75. Normal plasma is a a. clear, colorless, watery fluid containing about 10% solutes. b. clear or slightly hazy, pale yellow fluid that is 91% water. c. cloudy, completely colorless fluid containing 45% solutes. d. slightly hazy, pale yellow fluid that is close to 55% water.

75. Answer: b WHY: A plasma specimen is obtained by centrifuging blood collected in an anticoagulant tube. Centrifugation separates the cells from the liquid (plasma) portion of the specimen, which is a clear to slightly hazy (due to fibrinogen), pale yellow fluid that is 91% water and 9% solutes (dissolved substances).

76. Which of the following is an abnormal finding in the blood? a. Antibodies b. Bacteria c. Blood cells d. Platelets

76. Answer: b WHY: Blood is a mixture of fluid and cells. The fluid portion, plasma, is approximately 91% water and 9% dissolved substances such as antibodies, nutrients, minerals, and gases. Red blood cells, white blood cells, and platelets make up the cellular portion of blood, referred to as the formed elements. Bacteria are not found in the blood under normal circumstances because the immune system recognizes them as foreign and destroys them.

77. Which blood cell contains a nucleus? a. Erythrocyte b. Leukocyte c. Thrombocyte d. Reticulocyte

77. Answer: b WHY: All leukocytes (white blood cells) contain nuclei. Thrombocytes (platelets) and mature erythrocytes (red blood cells) do not have nuclei. A reticulocyte is an immature red blood cell that contains remnants of nuclear material but not a complete nucleus.

78. A reticulocyte count identifies immature a. lymphocytes. b. neutrophils. c. red blood cells. d. white blood cells.

78. Answer: c WHY: Reticulocytes are immature red blood cells that contain remnants of RNA and other material from their nuclear phase in the bone marrow. The remnants can be seen when blood is stained with a special stain used to perform a manual reticulocyte count.

79. Which blood cell increases in allergic reactions and pinworm infestations? a. Basophil b. Eosinophil c. Lymphocyte d. Neutrophil

79. Answer: b WHY: An eosinophil (Fig. 6-19B) is a type of granulocytic white blood cell that can ingest and detoxify foreign protein and help turn off immune reactions. Consequently, eosinophils (eos) increase in numbers during allergic reactions and infestations of parasites such as pinworms.

81. Which of the following would be considered a normal erythrocyte count? a. 4.5 million/mm3 b. 6.0 million/mm3 c. 10.5 million/mm3 d. 20.0 million/mm3

81. Answer: a WHY: Red blood cells (erythrocytes) are normally the most numerous formed elements in the blood (see Figs. 6-20 refer to #87 and 6-21), averaging 4.5 to 5.0 million/mm3 of blood. Therefore, an erythrocyte count of 4.5 million/mm3 would be considered normal.

82. Red blood cells are produced in the a. bloodstream. b. bone marrow. c. lymph nodes. d. thymus gland.

82. Answer: b WHY: The production and development of red blood cells (erythrocytes) occurs in the bone marrow by a process called erythropoiesis.

83. The primary function of red blood cells is to a. deliver nutrients to the body tissues. b. produce antibodies to combat infection. c. transport carbon dioxide to the lungs. d. transport oxygen to cells in the body.

83. Answer: d WHY: The primary function of red blood cells is to transport oxygen from the lungs to the tissues. A secondary function of red blood cells is to transport carbon dioxide from the tissues to the lungs. Nutrients are dissolved in the plasma, not transported by red blood cells. Certain white blood cells, but not red blood cells, produce antibodies.

84. A leukocyte is a a. lymphatic cell. b. platelet stem cell. c. red blood cell. d. white blood cell.

84. Answer: d WHY: The medical term for a white blood cell is "leukocyte." The word root "leuk" means "white," and the suffix "-cyte" means "cell."

85. Which blood cell can pass through blood vessel walls? a. Erythrocyte b. Leukocyte c. Reticulocyte d. Thrombocyte

85. Answer: b WHY: Leukocytes have extravascular function, which means that they do their job outside of the bloodstream. They leave the bloodstream and pass through the spaces between the cells in the walls of blood vessels by a process called diapedesis. Erythrocytes, reticulocytes, and thrombocytes have intravascular function and cannot pass through intact blood vessel walls.

86. Which type of cell destroys pathogens by phagocytosis? a. Erythrocyte b. Neutrophil c. Red blood cell d. Thrombocyte

86. Answer: b WHY: The main function of white blood cells (WBCs) is to neutralize or destroy pathogens. Neutrophils (see Fig. 6-19A) are a type of WBC that destroys pathogens by phagocytosis, a process in which a pathogen or other foreign matter is surrounded, engulfed, and destroyed by the WBC. This process is also used to remove disintegrated tissue.

87. Which of the following is a short term for neutrophils? a. Eos b. Basos c. Monos d. Polys

87. Answer: d WHY: Neutrophils (see Fig. 6-19A) are polymorphonuclear (PMN), which means they have a nucleus that has several lobes connected by thin strands. Another term for this type of nucleus is "segmented." Consequently, neutrophils are often called polys, PMNs, or segs for short.

9. Which heart chamber delivers oxygen-rich blood to the ascending aorta? a. Left atrium b. Left ventricle c. Right atrium d. Right ventricle

9. Answer: b WHY: The ventricles, the lower chambers of the heart, are called delivering chambers because they deliver blood to the pulmonary and systemic systems. The left ventricle (see Fig. 6-7) delivers oxygen-rich blood through the aortic semilunar valve to the ascending aorta, which is the beginning of the systemic system. The right ventricle delivers deoxygenated blood through the pulmonary semilunar valve to the pulmonary artery. The right and left atria receive blood from the systemic and pulmonary systems, respectively.

90. Which type of cell is sometimes called a macrophage? a. Eosinophil b. Basophil c. Lymphocyte d. Monocyte

90. Answer: d WHY: Monocytes (Fig. 6-23B) that have left the bloodstream are sometimes referred to as macrophages because they are found in loose connective tissue where they phagocytize (engulf and destroy) particles much like cells of the reticuloendothelial (RE) system.

91. Some of these cells give rise to plasma cells. a. Eosinophils b. Lymphocytes c. Monocytes d. Neutrophils

91. Answer: b WHY: Lymphocytes (see Fig. 6-23A) play a role in immunity and are the second most numerous type of WBC. There are two main types of lymphocytes: T lymphocytes, which directly attack infected cells, and B lymphocytes, which differentiate into plasma cells. Plasma cells produce antibodies that are released into the bloodstream where they circulate and attack foreign antigens.

92. Which of the following would be considered a normal platelet count? a. 20,000/mm3 b. 70,000/mm3 c. 300,000/mm3 d. 600,000/mm3

92. Answer: c WHY: The number of platelets (see Fig. 6-22) in the blood of the average adult is between 150,000 and 400,000 per cubic millimeter (mm3). Therefore, a platelet count of 300,000/mm3 is considered normal.

93. Platelets are also called a. erythrocytes. b. leukocytes. c. neutrophils. d. thrombocytes.

93. Answer: d WHY: Thromb means "clotting" and cyte means "cell." "Thrombocyte" is the medical term for platelets, which are cells that function in the clotting process.

124. Platelet activation and blood clotting in general can be inhibited by a. aspirin. b. antibiotics. c. sulfates. d. vitamins.

124. Answer: a WHY: Aspirin (salicylic acid) inhibits platelet activation (and blood clotting in general) and is often prescribed as a "blood thinner" or "antiplatelet agent" to those at risk of heart attack or stroke.

136. One function of the lymphatic system is to a. control all body activities. b. make coagulation factors. c. remove and destroy bacteria. d. secrete regulating hormones.

136. Answer: c WHY: The lymphatic system (Fig. 6-26) returns tissue fluid to the bloodstream, protects the body by removing microorganisms and impurities, processes lymphocytes, and delivers fats absorbed from the small intestine to the bloodstream. The lymphatic system does not control all body activities, make coagulation factors, or secrete regulating hormones.

94. A platelet is part of a bone marrow cell called a a. granulocyte. b. macrophage. c. megakaryocyte. d. T lymphocyte.

94. Answer: c WHY: A platelet is not a true cell, but a fragment of a large bone marrow cell called a megakaryocyte. When separated into parts (mega-karyo-cyte), this term means "large-nucleated cell."

95. Which of the following are normally the most numerous of the formed elements? a. Platelets b. Red blood cells c. Reticulocytes d. White blood cells

95. Answer: b WHY: The formed elements are red blood cells, white blood cells, and platelets. The erythrocyte (red blood cell) is normally the most numerous formed element in the blood, averaging 4.5 to 5.0 million/mm3 of blood (see Fig. 6-21).

96. A person's blood type is determined by the presence or absence of certain types of a. antibodies on the surfaces of the red blood cells. b. antibodies on the surfaces of the white blood cells. c. antigens on the surfaces of the red blood cells. d. antigens on the surfaces of the white blood cells.

96. Answer: c WHY: Human blood type, which is inherited, is determined by the presence or absence of certain types of antigens on the surface of the red blood cells. The ABO blood group system recognizes four blood types based on two antigens called A and B. Type A individuals have the A antigen, type B have the B antigen, type AB have both antigens, and type O have neither A nor B antigen. The Rh system is based on the presence or absence of the Rh antigen. Rh-positive individuals have the Rh antigen, and Rh-negative individuals lack the Rh antigen.

97. To prevent sensitization, Rh immunoglobulin is given to a. pregnant women who bleed throughout the pregnancy. b. Rh-negative mothers who deliver Rh-positive babies. c. Rh-positive babies immediately after they are born. d. Rh-positive mothers who deliver Rh-negative babies.

97. Answer: b WHY: Rh sensitization means an Rh-negative individual has been exposed to Rh-positive blood and is thus able to produce antibodies directed against the Rh factor. To prevent sensitization from an Rh-positive fetus, an Rh-negative woman may be given Rh immunoglobulin at certain times during her pregnancy as well as immediately after the baby's birth. Rh immunoglobulin destroys any Rh-positive fetal cells that may have entered her bloodstream, thus preventing sensitization. Only an Rh-negative person can become sensitized to the Rh factor. Carrying an Rh-negative fetus will not cause sensitization.

10. Which heart chamber receives blood from the systemic system? a. Left atrium b. Left ventricle c. Right atrium d. Right ventricle

10. Answer: c WHY: The atria (sing., atrium), the upper chambers of the heart (see Fig. 6-7), are called receiving chambers because they receive blood from the systemic and pulmonary systems. The right atrium receives blood from the systemic system via the superior (upper) and inferior (lower) venae cavae. The left atrium receives blood from the pulmonary system. The right and left ventricles deliver blood to the pulmonary and systemic systems, respectively.

12. The right atrioventricular valve is also called the a. bicuspid valve. b. pulmonic valve. c. semilunar valve. d. tricuspid valve.

12. Answer: d WHY: The right atrioventricular (AV) valve, located between the right atrium and the right ventricle (see Fig. 6-7), is also called the tricuspid valve because it has three flaps, or cusps. The bicuspid (two cusps) valve, also called the mitral valve, is located between the left atrium and the left ventricle. The pulmonic valve is located at the exit of the right ventricle. The pulmonic valve and the aortic valve, which are located at the exit of the left atrium, are called semilunar valves because they are crescent-shaped, like a half-moon.

13. Which valve gets its name from its resemblance to a bishop's hat? a. Aortic valve b. Mitral valve c. Pulmonic valve d. Tricuspid valve

13. Answer: b WHY: The left atrioventricular (AV) valve (see Fig. 6-7) is called the bicuspid valve because it has two cusps (flaps). It is also called the mitral valve, because the two cusps resemble a miter, the two-sided, pointed hat worn by a bishop.

14. The structure that separates the right and left ventricles of the heart is called the a. atrioventricular septum. b. interatrial septum. c. interventricular septum. d. myocardial septum.

14. Answer: c WHY: A wall that divides two cavities is called a septum. The wall that separates the right and left ventricles of the heart is called the interventricular septum (see Fig. 6-7). The interatrial septum separates the right and left atria. The walls of the heart, including the septa, have a thick middle layer of muscle called the myocardium. The atrioventricular septum is a small section of septum that separates the right atrium from the left ventricle.

15. The heart muscle gets its blood supply from the a. carotid arteries. b. coronary arteries. c. pulmonary arteries. d. pulmonary veins.

15. Answer: b WHY: The heart does not receive oxygen or nourishment from the blood passing through it. The heart receives its blood supply from the right and left coronary arteries, which are the first branches off of the aorta, just beyond the aortic semilunar valve. The carotid arteries carry blood to the brain. The pulmonary arteries carry blood from the right ventricle to the lungs. The pulmonary veins carry blood from the lungs back to the left atrium.

16. Which structures keep the atrioventricular valves from flipping back into the atria? a. Chordae tendineae b. Myocardial septa c. Purkinje fibers d. Semilunar cusps

16. Answer: a WHY: The atrioventricular valves are attached to the walls of the ventricles by thin threads of tissue called chordae tendineae (Fig. 6-8). These keep the valves from flipping back into the atria, which helps them close properly so that blood does not flow backward into the atria.

17. Myocardial ischemia is a condition that results from a. complete blockage of a coronary artery. b. death of a portion of myocardial tissue. c. malfunction of an atrioventricular valve. d. partial obstruction of a coronary artery.

17. Answer: d WHY: Partial obstruction of a coronary artery or one of its branches can reduce blood flow to a point where it can no longer meet the oxygen needs of the heart muscle, a condition called myocardial ischemia.

20. Which is an abbreviation for a test that traces the electrical impulses of the heart? a. ALT b. ECG c. EEG d. Tent

20. Answer: b WHY: An electrocardiogram (ECG or EKG) (Fig. 6-9) is the actual record of electrical currents that correspond to each event in heart muscle contraction. Alanine aminotransferase (ALT) is an enzyme associated with liver function. An electroencephalogram (EEG) measures electrical currents from the brain. Troponin T (TnT) is a protein released during muscle damage. Cardiac TnT (cTNT) is specific to heart muscle.

21. One complete contraction and subsequent relaxation of the heart is called one cardiac a. cycle. b. diastole. c. output. d. systole.

21. Answer: a WHY: A cardiac cycle is defined as one complete contraction and relaxation of the heart. Diastole is the relaxing phase of the heart. Cardiac output is the volume of blood pumped by the heart in 1 minute. Systole is the contracting phase of the heart.

22. Systole is the a. closing of the semilunar valves. b. completion of one cardiac cycle. c. contracting phase of the heart. d. relaxation stage of the heart.

22. Answer: c WHY: The medical term for the contracting phase of the cardiac cycle is systole. The closing of the semilunar valves is what creates the second sound of the heartbeat. A cardiac cycle is one complete contraction and subsequent relaxation of the heart. The relaxation phase of the heart is called diastole.

25. On an electrocardiogram, which wave represents the activity of the ventricles? a. P b. P and T c. QRS and P d. QRS and T

25. Answer: d WHY: On an electrocardiogram tracing (see Fig. 6-9), the QRS complex along with the T wave represents the electrical activity of the ventricles, while the P wave by itself represents the activity of the atria.

3. In numerical order, the structures indicated by numbers 4 and 15 in Figure 6-1 are the a. aortic valve and the bicuspid valve. b. mitral valve and the pulmonic valve. c. right and left atrioventricular valves. d. tricuspid valve and the aortic valve.

3. Answer: d WHY: Number 4 points to the tricuspid valve, also called the right atrioventricular valve, because it is between the right atrium and the right ventricle. Number 15 points to the aortic valve, located at the exit of the left ventricle where blood is delivered to the aorta (see Fig. 6-7).

38. Which of the following veins is found in the leg? a. Brachial b. Cephalic c. Femoral d. Median

38. Answer: c WHY: The femoral vein accompanies the femoral artery in the leg (Fig. 6-11) and is a continuation of the popliteal vein. The brachial, cephalic, and median veins are all found in the arm.

4. In numerical order, the structures indicated by numbers 5 and 12 in Figure 6-1 are the a. left atrium and right ventricle. b. left ventricle and right atrium. c. right atrium and left ventricle. d. right ventricle and left atrium.

4. Answer: d WHY: Number 5 points to the right ventricle, which receives blood from the right atrium and delivers it to the pulmonary system. Number 12 points to the left atrium, which receives oxygen-rich blood from the pulmonary system and delivers it to the left ventricle (see Fig. 6-7).

40. Which of the following veins carries oxygen-rich blood? a. Pulmonary b. Saphenous c. Subclavian d. Vena cava

40. Answer: a WHY: The pulmonary vein carries oxygenated (oxygen-rich) blood from the lungs back to the heart (see Fig. 6-10). All vessels that return blood to the heart are called veins. All vessels that carry blood away from the heart are called arteries. The general rule of thumb that arteries carry oxygenated blood is true only for the systemic circulation. In the pulmonary circulation, the vessel that carries oxygenated (oxygen-rich) blood from the lungs is called a vein because it is returning the blood to the heart.

41. Normal systemic arterial blood is a. dark blue. b. bright red. c. bluish red. d. dark red.

41. Answer: b WHY: Because it is full of oxygen, normal systemic arterial blood is bright red. Normal systemic venous blood is dark red with a bluish tinge. Regardless of what some people think, no one has blue blood.

42. The largest artery in the body is the a. aorta. b. carotid. c. femoral. d. vena cava.

42. Answer: a WHY: At the start of the systemic arterial circulation, the aorta is almost 1-in wide and is the largest artery in the body. The carotid artery in the neck and the femoral artery in the leg are large arteries but not as large as the aorta. The venae cavae (sing., vena cava) are the largest veins in the body.

43. The longest vein in the body is the a. great saphenous. b. median cubital. c. inferior vena cava. d. right pulmonary.

43. Answer: a WHY: The great saphenous vein runs the entire length of the leg (see Fig. 6-11) and is considered the longest vein in the body. The median cubital is a relatively short vein located in the antecubital fossa of the arm. The inferior vena cava, which returns systemic blood to the lower right atrium, is one of the largest veins in the body but not the longest. The right pulmonary vein returns oxygen-rich blood to the heart from the lungs and is nowhere near as long as the great saphenous.

5. Which of the following is a function of the circulatory system? a. Carrying oxygen to the tissue cells b. Conveying afferent nerve impulses c. Excreting wastes from the body d. Producing the formed elements

5. Answer: a WHY: A major role of the circulatory system is to carry oxygen to the cells and take carbon dioxide away from the cells to the lungs for expiration. The nervous system conveys nerve impulses. Wastes are primarily excreted by the digestive system. Some waste is excreted by sweat glands of the skin. The formed elements (blood cells) are produced in the bone marrow of the skeletal system.

58. In numerical order, the veins identified by numbers 1, 2, and 3 in Figure 6-4 are the a. accessory cephalic, median, and median basilic. b. cephalic, median basilic, and accessory basilic. c. median basilic, accessory cephalic, and median. d. median cephalic, median basilic, and median.

58. Answer: d WHY: The vein identified by number 1 is the median cephalic vein. The vein identified by number 2 is the median basilic vein. The vein identified by number 3 is the median vein. (See the M-pattern veins in Fig. 6-16.)

59. In numerical order, the veins identified by numbers 1, 2, and 3 in Figure 6-5 are the a. basilic, dorsal metacarpal, and cephalic. b. brachial, dorsal metacarpal, and basilic. c. cephalic, dorsal metacarpal, and basilic. d. median, dorsal metacarpal, and cephalic.

59. Answer: a WHY: The vein identified by number 1 is the basilic vein. The veins identified by number 2 are the dorsal metacarpal veins. The vein identified by number 3 is the cephalic vein (Fig. 6-17).

69. Which of the following is an abbreviation used for a vascular system test? a. ADH b. CSF c. DIC d. RPR

69. Answer: c WHY: DIC is the abbreviation for disseminated intravascular coagulation. A DIC test or screen is a series of tests used to detect diffuse, uncontrolled coagulation throughout the vascular system. In DIC, continuous generation of thrombin causes depletion of several clotting factors to such an extent that generalized bleeding may occur. Antidiuretic hormone (ADH) is an endocrine system test. A cerebrospinal fluid (CSF) analysis is a nervous system test. Rapid plasma reagin (RPR), a syphilis test, is a reproductive system test.

7. The middle layer of the heart is called the a. endocardium. b. epicardium. c. myocardium. d. pericardium.

7. Answer: c WHY: The heart (see Fig. 6-7) has three layers. The myocardium is the thick muscular middle layer of the heart. The endocardium, the inner layer, is the thin membrane lining the inside of the heart. The epicardium is the thin outer layer of the heart. The pericardium is the fluid-filled sac surrounding the heart.

73. Normal adult blood volume is approximately a. 2 L. b. 4 L. c. 5 L. d. 8 L.

73. Answer: c WHY: The average 154-lb adult has approximately 5 L, or 5.2 qt, of blood. A more exact blood volume can be calculated based on the fact that the average adult has 70 mL of blood for each kilogram of weight.

8. How many chambers are there in the human heart? a. One b. Two c. Four d. Six

8. Answer: c WHY: The human heart (see Fig. 6-7) has two sides, a right and a left. Each side has two chambers, an upper and a lower. The right and left upper chambers are called atria (sing., atrium) and the right and left lower chambers are called ventricles.

80. How large is a normal erythrocyte? a. 4 to 5 µm b. 7 to 8 µm c. 8 to 10 µm d. 10 to 12 µm

80. Answer: b WHY: Normal erythrocytes (Fig. 6-20) are described as anuclear biconcave discs that are approximately 7 to 8 µm in diameter.

88. Which formed element is the first to play a role in sealing an injury to a blood vessel? a. Erythrocyte b. Leukocyte c. Platelet d. Reticulocyte

88. Answer: c WHY: Injury to a blood vessel exposes protein material in the vessel wall. Contact with this material causes platelets (Fig. 6-22) to degranulate and stick to one another (platelet aggregation) and to the injured area (platelet adhesion). This results in the formation of a platelet plug that temporarily seals off the injury. If the injury is large, a fibrin clot that includes all the formed elements (RBCs, WBCs, and platelets) is eventually generated.

89. Which of the following is an anuclear biconcave disc? a. Erythrocyte b. Granulocyte c. Leukocyte d. Thrombocyte

89. Answer: a WHY: Erythrocytes (red blood cells) (see Figs. 6-20 refer to #87 and 6-21) are described as being anuclear (nonnucleated), biconcave (curved inward on both sides) discs approximately 7 to 8 µm in diameter.