Ch. 25

Question 1

1. Which of the following denotes the correct sequence of blood movement through the human heart?
   a. Vena cavae → left atrium → left ventricle → pulmonary artery → pulmonary vein → right atrium → right ventricle → aorta
   b. Vena cavae → right atrium → right ventricle → pulmonary artery → pulmonary vein → left atrium → left ventricle → aorta
   c. Vena cavae → right atrium → right ventricle → pulmonary vein → pulmonary artery → left atrium → left ventricle → aorta
   d. Aorta → left atrium → left ventricle → pulmonary artery → pulmonary vein → right atrium → right ventricle → vena cavae
   e. Vena cavae → right ventricle → right atrium → pulmonary artery → pulmonary vein → left ventricle → left atrium → aorta

Answer 1

B

Question 2

6. Which of the following statements regarding cardiac output is true?
   a. It is independent of stroke volume.
   b. It is the product of heart rate and stroke volume.
   c. It remains constant per gram of heart tissue.
   d. It is the heart rate divided by stroke volume.
   e. It is the product of heart rate and blood pressure.

Answer 2

B

Question 3

9. The myocardium of tunas is
   a. composed of an outer compact layer with coronary vessels and an inner spongy layer.
   b. spongy, with little or no development of coronary vessels.
   c. compact, with coronary arteries and veins.
   d. a mixed structure, with blood flowing from lumen into coronary veins.
   e. of an unknown type.

Answer 3

A

Question 4

10. Crustaceans primarily have _______ hearts.
    a. myogenic
    b. neurogenic
    c. hemogenic
    d. plyogenic
    e. noninnervated

Answer 4

B

Question 5

11. The ________ prevents the initial depolarization at the S-A node from spreading across the heart from the atria through the ventricles and ending at the tip of the septum.
    a. S-A node
    b. atrial myocardium
    c. connective tissue between the atria and ventricles
    d. interventricular septum
    e. Purkinje fibers

Answer 5

C

Question 6

12. The pacemaker of a lobster heart is
    a. composed of specialized myocardium that functions in a similar manner to the S-A node.
    b. composed of specialized myocardium that functions as a central pattern generator.
    c. a series of neurons connected to and controlled by the brain.
    d. a posterior cardiac neuron that functions as a cellular oscillator and central pattern generator.
    e. a series of cardiac neurons that all fire action potentials simultaneously to contract the heart.

Answer 6

D

Question 7

13. The P wave of the EKG is produced by the
    a. contraction of the atria.
    b. contraction of the ventricles.
    c. depolarization of the atria.
    d. repolarization of the atria.
    e. diastole of the heart.

Answer 7

C

Question 8

14. Which of the following describes the Frank-Starling mechanism?
    a. An increase in the filling time of the ventricles increases the contraction pressure.
    b. Increasing diastolic pressure increases arterial pressure.
    c. Increasing flow from the heart increases arterial pressure.
    d. Increasing pressure in the heart increases outflow.
    e. Stretching of the cardiac muscle increases the force of its contraction at the cellular level.

Answer 8

E

Question 9

15. The mean pressure in the systemic aorta in a healthy human is about _______ mm Hg.
    a. 120
    b. 95
    c. 75
    d. 50
    e. 12.7

Answer 9

B

Question 10

16. A tall human with normal blood pressure standing upright would be expected to have a pressure of about_________ mm Hg in the leg artery measured 130 cm below the heart.
    a. 30
    b. 95
    c. 120
    d. 150
    e. 195

Answer 10

E

Question 11

17. According to the Poiseuille equation, which of the following does not directly affect flow rate?
    a. Temperature of the tube
    b. Viscosity of the fluid
    c. Radius of the lumen of the tube
    d. Length of the tube
    e. Pressure at the entry of the tube

Answer 11

A

Question 12

18. Halving the radius of a vessel _______ the resistance to flow through the vessel by a factor of _______.
    a. decreases; 4
    b. decreases; 16
    c. increases; 4
    d. increases; 16
    e. None of the above; a change in the radius does not affect the resistance to flow.

Answer 12

D

Question 13

19. The most important factor modifying flow in blood vessels is the
    a. pressure in the vessel.
    b. diameter of the vessel.
    c. viscosity of fluid in the vessel.
    d. length of the vessel.
    e. temperature of the vessel.

Answer 13

B

Question 14

20. The principle that explains why blood capillaries can be exceedingly thin-walled and yet resist substantial pressures is called
    a. Laplace’s law.
    b. Poiseuille’s equation.
    c. Hagen’s equation.
    d. the Frank-Starling mechanism.
    e. the laminar flow equation.

Answer 14

A

Question 15

21. Which of the following statements regarding microcirculatory beds is false?
    a. Smooth muscles in the walls of arterioles are responsible for vasoconstriction and vasodilation.
    b. Anastomoses provide more than one possible path from an arteriole to a venule.
    c. The walls of capillaries consist of only the vascular endothelium.
    d. Capillaries are the preeminent sites of O2 and water exchange.
    e. Venules participate in the control of blood flow distribution by vasodilation and vasoconstriction.

Answer 15

E

Question 16

27. The main difference between the pulmonary circuit and the systemic circuit is that the pulmonary circuit
    a. is longer.
    b. has a higher resistance.
    c. produces lower pressures.
    d. produces lower flows.
    e. has a lower cardiac output.

Answer 16

C

Question 17

28. Which of the following best describes the contractile properties of the heart of the elasmobranch fish?
    a. There are four chambers and only the atria and ventricles contract.
    b. There are only two chambers, the atria and ventricle, and they both contract.
    c. There are four chambers and three contract.
    d. There are four chambers and all four contract.
    e. None of the above

Answer 17

D

Question 18

29. Which of the following is not a characteristic of a typical teleost cardiovascular system?
    a. The heart receives oxygenated blood flowing from the gills.
    b. Cardiac outputs are lower compared to those of mammals of similar size.
    c. The heart empties almost completely at the end of each systole.
    d. Blood pressure drops significantly as blood passes through the gills.
    e. Arterial pressures are lower compared to those of mammals.

Answer 18

A

Question 19

32. In fish that have an air-breathing organ (ABO),
    a. the blood leaving the ABO mixes with systemic and venous blood.
    b. the blood leaving the ABO mixes with blood leaving the gills.
    c. there are rarely functioning gills.
    d. the blood enters the ABO following the exit from the gills.
    e. the blood leaving the ABO enters the gills.

Answer 19

A

Question 20

33. Which of the following does not represent a difference between the African lungfish Protopterus and the typical teleost fish?
    a. The veins of the lungfish lung lead directly to the left side of the atrium of the heart rather than connecting with the systemic venous vasculature.
    b. The ventral aorta is extremely long and branched in lungfish.
    c. The atrium and the ventricles of lungfish are partially divided into left and right halves by septa.
    d. The conus arteriosis of lungfish has longitudinal ridges that divide the lumen into two channels.
    e. The four pairs of branchial arteries arise immediately from the conus arteriosus in lungfish.

Answer 20

B

Question 21

37. Which of the following animals does not modulate blood flow to the lungs independently of blood flow to the rest of the body?
    a. Lungfish
    b. Amphibians
    c. Crocodilians
    d. Birds
    e. Turtles

Answer 21

D

Question 22

38. Which of the following structures aids crocodilians in diverting blood flow during diving?
    a. Cog valve
    b. Foramen of Panizza
    c. Flap valve
    d. Both a and b
    e. All of the above

Answer 22

E

Question 23

39. The _______ circulatory system of squids and octopuses consist of _______.
    a. open; two branchial hearts and one systemic heart
    b. open; two systemic hearts and one branchial heart
    c. closed; two systemic hearts and one branchial heart
    d. closed; two branchial hearts and one systemic heart
    e. parallel; many lymphatic hearts

Answer 23

D

Question 24

43. A squid meets the increased demand for O2 at the tissues during intense exercise by
    a. increasing its circulation rate.
    b. pulling more O2 from the blood.
    c. switching to another form of hemoglobin.
    d. increasing the amount of respiratory pigment per unit volume.
    e. making use of anaerobic metabolism only.

Answer 24

A

Question 25

44. If a squid and a fish both double cardiac output during exercise, circulatory oxygen delivery to the tissues in _______ will _______.
    a. both animals; remain the same
    b. both animals; double
    c. the fish; be higher than in the squid
    d. the squid; be higher than in the fish
    e. None of the above

Answer 25

C

Question 26

45. Small spaces among cells of nonvascular organs and tissues are called
    a. lacunae.
    b. sinuses.
    c. ostia.
    d. ganglia.
    e. interstitia.

Answer 26

A

Question 27

46. Which of the following statements regarding the lobster circulatory system is false?
    a. Hemolymph returns through holes in the heart called ostia.
    b. All vessels connected to the heart are arteries.
    c. The primary force that refills the heart is elastic rebound.
    d. The heart is suspended within an array of suspensory ligaments in the pericardial sinus.
    e. There is a clear distinction between blood and interstitial fluid.

Answer 27

E

Question 28

50. The blood circulation of crustaceans _______ that of fish primarily because of _______.
    a. is faster than; lower resistance
    b. is faster than; higher pressure
    c. is slower than; lower pressure
    d. is slower than; higher resistance
    e. has a similar rate to; larger vessels

Answer 28

A

Question 29

1. In the human heart, oxygenated blood is carried from the lungs to the heart by the
   a. vena cava.
   b. capillaries.
   c. aorta.
   d. pulmonary arteries.
   e. pulmonary veins.

Answer 29

E

Question 30

2. Cardiac output is directly proportional to
   a. heart rate.
   b. stroke volume.
   c. blood pressure.
   d. Both a and b
   e. Both a and c

Answer 30

D

Question 31

3. The hearts of vertebrates are myogenic, meaning that
   a. neurons control the inherent pace of the heart.
   b. the myocardium is compact and therefore has a coronary circulation.
   c. the impulse to contract originates within the muscle tissue.
   d. there is a cardiac conduction system.
   e. the beat originates in the atria.

Answer 31

C

Question 32

4. The QRS complex arises from
   a. ventricular depolarization.
   b. ventricular contraction.
   c. ventricular repolarization.
   d. ventricular diastole.
   e. atrial contraction.

Answer 32

A

Question 33

5. Mean blood pressure in the brain of a standing person _______ the blood pressure at the heart.
   a. is higher than
   b. is lower than
   c. is exactly the same as
   d. is approximately the same as
   e. has no relationship with

Answer 33

B

Question 34

6. Which of the following has the greatest effect on the flow of liquid through a tube?
   a. Pressure difference
   b. Viscosity of the liquid
   c. Length of the tube
   d. Radius of the tube
   e. Temperature

Answer 34

D

Question 35

7. Flow rate equals the difference in blood pressure between the entry of the vascular system and the exit vessels, divided by
   a. the viscosity.
   b. vascular resistance.
   c. the viscosity multiplied by radius4.
   d. radius4.
   e. π multiplied by radius4.

Answer 35

B

Question 36

8. Which of the following statements comparing the circulatory systems in mammals and birds is true?
   a. Birds have far smaller hearts per gram.
   b. Mammals have, on average, higher systolic blood pressures.
   c. Birds have a smaller cross-sectional area of capillaries per gram.
   d. Mammals have a higher pressure systemic circuit.
   e. Birds and mammals have essentially identical circulatory systems.

Answer 36

E

Question 37

9. In which of the following vessels is there a lack of pressure pulse?
   a. Large arteries, terminal arteries, and arterioles
   b. Terminal arteries, arterioles, capillaries, and venules
   c. Capillaries, venules, and veins
   d. Venules and veins
   e. Veins only

Answer 37

C

Question 38

10. Which vessels of the systemic vascular system have the highest total cross-sectional area?
    a. Arterial vessels
    b. Capillary beds
    c. Venous vessels
    d. Lymphatic vessels
    e. Both a and c have equal areas.

Answer 38

B

Question 39

11. In a mammal, blood pressure is lowest in the
    a. arteries.
    b. arterioles.
    c. capillaries.
    d. venules.
    e. veins.

Answer 39

E

Question 40

12. Excessive protein in the blood plasma will _______ the loss of fluid through the capillaries.
    a. increase
    b. decrease
    c. have no effect on
    d. increase, and then decrease
    e. None of the above; more information is needed in order to make this determination.

Answer 40

B

Question 41

13. When a mammal exercises, oxygen delivery is increased by
    a. increased blood flow.
    b. the extraction of more O2 per unit volume of blood that circulates.
    c. a lowering of resistance in the systemic vasculature.
    d. Both a and b
    e. All of the above

Answer 41

E

Question 42

14. In _______, there is no separation of oxygenated and deoxygenated blood at the heart.
    a. a teleost fish
    b. a lungfish
    c. amphibians
    d. reptiles
    e. mammals

Answer 42

A

Question 43

15. The chambers of the teleost fish heart are
    a. the atria and the ventricles.
    b. the atria, ventricles, and bulbus arteriosus.
    c. the sinus venosus, atrium, and ventricles.
    d. the sinus venosus, atrium, ventricle, and bulbus arteriosus.
    e. the sinus venosus, atrium, ventricle, and conus arteriosus.

Answer 43

D

Question 44

16. In a fish that has an air-breathing organ,
    a. there are not likely to be functioning gills.
    b. the blood leaving the ABO mixes with blood leaving the gills.
    c. the blood leaving the ABO mixes with systemic venous blood.
    d. the blood enters the ABO following its exit from the gills.
    e. All of the above

Answer 44

C

Question 45

17. Among nonavian reptiles, crocodilians are unique because they
    a. have birdlike blood pressures.
    b. have hearts that are large relative to their mass.
    c. can shunt blood.
    d. have a complete ventricular septum.
    e. have a comparatively high hemoglobin concentration.

Answer 45

D

Question 46

18. Which of the following statements about squid is false?
    a. Their systemic heart receives largely deoxygenated blood.
    b. They have a systemic heart and two branchial hearts.
    c. Their systemic heart is myogenic.
    d. Blood enters the systemic heart from the gills.
    e. Branchial hearts pump blood through the gills.

Answer 46

A

Question 47

19. In crustacean circulatory systems, deoxygenated blood from the tissues enters the heart via
    a. ostia.
    b. the cardinal veins.
    c. the dorsal abdominal artery.
    d. the dorsal abdominal vein.
    e. the sternal vein.

Answer 47

A

Question 48

20. Which of the following statements about the insect circulatory system is true?
    a. Insects have an open circulatory system and solely a diffusion-based system for delivering O2.
    b. Insects have a closed circulatory system and a tracheal system for delivering O2.
    c. Insects have an open circulatory system and a tracheal system for delivering O2.
    d. Insects have an open circulatory system and a derived lung for delivering O2.
    e. Insects have a closed circulatory system and solely a diffusion-based system for delivering O2.

Answer 48

C