Chapter 17

9. The tissue factor that contributes to humoral control of blood flow by causing vasoconstriction is: A) histamine. B) bradykinin. C) serotonin. D) nitric oxide.

C) serotonin.

4. During ventricular systole, closure of the atrioventricular (AV) valves coincides with: A) atrial chamber filling. B) aortic valve opening. C) isovolumetric contraction. D) semilunar valves opening.

C) isovolumetric contraction.

11. A patient has entered hypovolemic shock after massive blood loss in a car accident. Many of the patient's peripheral blood vessels have consequently collapsed. How does the Laplace law account for this pathophysiologic phenomenon? A) Blood pressure is no longer able to overcome vessel wall tension. B) Decreasing vessel radii have caused a decrease in blood pressure. C) Wall thickness of small vessels has decreased due to hypotension. D) Decreases in wall tension and blood pressure have caused a sudden increase in vessel radii.

A) Blood pressure is no longer able to overcome vessel wall tension.

18. A patient who lives with a diagnosis of angina pectoris has taken a sublingual dose of nitroglycerin to treat the chest pain he experienced while mowing his lawn. This drug has resulted in a release of nitric oxide, which will have what effect? A) Smooth muscle relaxation of vessels B) Decreased heart rate and increased stroke volume C) Increased preload D) Reduction of cardiac refractory periods

A) Smooth muscle relaxation of vessels

8. Long-term autoregulation of local blood flow in the microcirculation is mediated by: A) collateral circulation. B) arteriovenous shunting. C) autonomic nervous system. D) metabolic needs of the tissues.

A) collateral circulation.

2. Turbulent blood flow can be caused by a number of factors, including: A) increased velocity. B) short vessel length. C) high blood viscosity. D) layering of blood cells.

A) increased velocity.

5. The difference between the end-diastolic and end-systolic volumes is the: A) stroke volume. B) cardiac output. C) ejection fraction. D) cardiac reserve.

A) stroke volume.

6. Preload represents the volume work of the heart and is largely determined by: A) venous blood return. B) vascular resistance. C) force of contraction. D) ventricular emptying.

A) venous blood return.

16. A patient with a history of heart failure has been referred for an echocardiogram. Results of this diagnostic test reveal the following findings: heart rate 80 beats per minute; end-diastolic volume 120 mL; end-systolic volume 60 mL. What is this patient's ejection fraction? A) 200 mL B) 50% C) .80 D) 180 mL

B) 50%

17. A patient with a diagnosis of secondary hypertension has begun to experience signs and symptoms that are ultimately suggestive of decreased cardiac output. Which of the following factors that determine cardiac output is hypertension likely to affect most directly? A) Preload B) Afterload C) Contractility D) Heart rate

B) Afterload

12. In the days following a tooth cleaning and root canal, a patient has developed an infection of the thin, three-layered membrane that lines the heart and covers the valves. What is this patient's most likely diagnosis? A) Pericarditis B) Endocarditis C) Myocarditis D) Vasculitis

B) Endocarditis

20. Which of the following factors is the primary governor of the local control of blood flow? A) Action potential B) The nutritional needs of the tissue involved C) Cardiac contractility and preload D) Feedback from arterial baroreceptors and chemoreceptors

B) The nutritional needs of the tissue involved

1. In the arterial-venous circulatory system, pressure is inversely related to: A) velocity. B) volume. C) tension. D) viscosity.

B) volume.

14. Harmful effects on cardiac action potential are most likely to result from a deficit of which of the following electrolytes? A) Magnesium (Mg2+) B) Chloride (Cl-) C) Potassium (K+) D) Hydrogen carbonate (HCO3-)

C) Potassium (K+)

15. A male patient with a history of angina has presented to the emergency department with uncharacteristic chest pain and his subsequent ECG reveals T-wave elevation. This finding suggests an abnormality with which of the following aspects of the cardiac cycle? A) Atrial depolarization B) Ventricular depolarization C) Ventricular repolarization D) Depolarization of the AV node, bundle branches, and Purkinje system

C) Ventricular repolarization

3. Heart muscle differs from skeletal muscle tissue by being able to generate: A) contractions. B) calcium influx. C) action potentials. D) sarcomere binding.

C) action potentials.

7. A large increase in heart rate can cause: A) increased blood viscosity. B) loss of action potential. C) decreased stroke volume. D) reduced cardiac contractility.

C) decreased stroke volume.

10. The parasympathetic nervous system causes a slowing of the heart rate by increasing: A) norepinephrine. B) vessel constriction. C) vagus nerve activity. D) smooth muscle tone.

C) vagus nerve activity.

13. Following several weeks of increasing fatigue and a subsequent diagnostic work-up, a patient has been diagnosed with mitral valve regurgitation. Failure of this heart valve would have which of the following consequences? A) Backup of blood from the right atrium into the superior vena cava B) Backflow from the right ventricle to the right atrium during systole C) Inhibition of the SA node's normal action potential D) Backflow from the left ventricle to left atrium

D) Backflow from the left ventricle to left atrium

19. Release of which of the following humoral factors will result in vasodilation? A) Norepinephrine B) Angiotensin II C) Serotonin D) Histamine

D) Histamine