BY 32 – SPRING 2000

Section 2412

EXAM 3

NAME ___________________________________

Instructions: Record your answers directly on this sheet by circling the correct response. For each question, choose the single best response.

1. The amount of blood pumped by the heart each minute is referred to as the: (C)

a. stroke volume.

b. residual volume.

c. cardiac output.

d. total peripheral resistance.

2. Venous blood returning from the systemic circulation drains first to which heart chamber? (A)

a. Right atrium

b. Right ventricle

c. Left atrium

d. Left ventricle

3. The heart is located within a space of the thoracic cavity called the: (D)

a. pericardial cavity.

b. coronary sinus.

c. pleural cavity.

d. Mediastinum.

4. Which of the following structures consists of a single layer of mesothelial cells? (C)

a. The endocardium

b. The myocardium

c. The serous pericardium

d. The fibrous pericardium

5. The thickest layer of the heart is called the: (B)

a. fibrous pericardium.

b. myocardium.

c. epicardium.

d. endocardium.

6. The right atrium has two portions consisting of a smooth walled portion and a rough walled portion made up of structures called: (B)

a. trabeculae carnae.

b. pectinate muscles.

c. papillary muscles.

d. chordae tendinea.

7. The right coronary artery and the circumflex artery lie in a groove of the heart called the: (A)

a. atrioventricular sulcus.

b. anterior interventricular sulcus.

c. posterior interventricular sulcus.

d. interventricular septum.

8. Connecting the aorta and the pulmonary trunk is a vestigial structure called the: (D)

a. coronary sinus.

b. auricle.

c. chordae tendinae.

d. ligamentum arteriosum.

9. Because of its number of cusps, the right atrioventricular valve is called the: (B)

a. bicuspid valve.

b. tricuspid valve.

c. aortic semilunar valve.

d. pulmonary semilunar valve.

10. During ventricular systole, eversion of the atrioventricular valves is prevented by contraction of: (C)

a. the pectinate muscles.

b. the trabeculae carnae.

c. the papillary muscles.

d. the interventricular septum.

11. The fibrous skeleton of the heart consists of the roots of the great vessels, the membranous interventricular septum and the: (C)

a. bundle of His.

b. atrioventricular sulcus.

c. annulus fibrosus.

d. coronary sinus.

12. Both coronary arteries are branches of which of the following blood vessels? (A)

a. The aorta

b. The pulmonary trunk

c. The circumflex artery

d. The superior vena cava

13. Blood flow during the coronary circulation virtually ceases during which phase of the cardiac cycle? (D)

a. Isovolumetric relaxation

b. Rapid ventricular filling

c. Diastasis

d. Ventricular systole

14. The condition in which thoracic pain is generated in response to a brief interruption of coronary blood flow is called: (D)

a. rheumatic fever.

b. pericarditis.

c. cardiac tamponade.

d. angina .

15. Action potentials pass from cell to cell in the heart via which of the following structures? (D)

a. T tubules

b. Cross bridges

c. Desmosomes

d. Gap junctions

16. In general blood vessels which return blood to the heart are called: (C)

a. elastic arteries.

b. resistance vessels.

c. veins.

d. capillaries.

17. Within an elastic artery, the portion that contains the tissue type endothelium is called the: (A)

a. tunica intima.

b. tunica media.

c. tunica adventitia.

d. internal elastic lamina.

18. Within a muscular artery, the portion that contains smooth muscle is called the: (B)

a. tunica intima.

b. tunica media.

c. tunica adventitia.

d. internal elastic lamina.

19. The outermost layer of large veins is called the: (C)

a. tunica intima.

b. tunica media.

c. tunica adventitia.

d. internal elastic lamina.

20. As a result of smooth muscle contraction, the dimensions of the lumen of arteries decrease in a process called: (B)

a. hyperpolarization.

b. vasoconstriction.

c. vasodilation.

d. autoregulation.

21. The smallest type of artery with a complete smooth muscle layer in the tunica media is called a(n): (C)

a. elastic artery.

b. muscular artery.

c. arteriole.

d. metarteriole.

22. Within a capillary bed, constriction of the precapillary sphincter shunts blood into: (B)

a. the capillaries.

b. the metarteriole.

c. the interstitial space.

d. the arterioles.

23. Of the various types of capillaries, those with the highest permeability are the: (D)

a. continuous capillaries in the brain.

b. continuous capillaries in the heart.

c. fenestrated capillaries.

d. discontinuous capillaries.

24. The cell type found just outside of the basement membrane of capillaries and postcapillary venules is called the: (D)

a. endothelial cell.

b. smooth muscle cell.

c. fibroblast.

d. pericyte.

25. Within the systemic circulation, most blood volume is found within: (D)

a. the heart.

b. the arteries.

c. the capillaries.

d. the veins.

26. The resting potential of a typical contractile cell of the heart is typically on the order of –90 mV, which is attributable to relatively high permeability of the cell membrane to which of the following ions? (B)

a. Na⁺

b. K⁺

c. Ca²⁺

d. Cl^-

27. When a contractile cell is brought to threshold by excitation from a neighboring cell, the rapid depolarization of the membrane is attributable to an increase in permeability of which of the following ions? (A)

a. Na⁺

b. K⁺

c. Ca²⁺

d. Cl^-

28. Which of the following cell types possess pacemaker potentials? (C)

a. Contractile cells of the atria

b. Contractile cells of the ventricle

c. Conducting cells of the AV node

d. Smooth muscle cells of the coronary arteries

29. Unlike contractile cells, the upstroke of the action potential in conducting cells of the SA node is due to an increase in permeability to: (C)

a. Na⁺

b. K⁺

^c. Ca²⁺

d. Cl^-

30. During ventricular systole, which part of the ventricles contract first? (A)

a. The interventricular septum.

b. The papillary muscles.

c. The right heart wall.

d. The left heart wall.

31. The portion of the conduction system of the heart which produces action potentials at the highest frequency is normally the: (A)

a. SA node.

b. AV node.

c. Bundle of His.

d. Purkinje cells.

32. The point at which about half of the atrium is depolarized is indicated by which point in the electrocardiogram (ECG or EKG)? (B)

a. Beginning of the P wave

b. Top of the P wave

c. Beginning of the QRS complex

d. Beginning of the T wave

33. Using the ECG (=EKG), heart rate can be determined from which of the following? (D)

a. The PQ segment

b. The ST segment

c. The PT segment

d. The RR segment

34. Using the ECG (=EKG), the condition of atrial fibrillation would be indicated by the absence of: (A)

a. P waves.

b. QRS complexes.

c. T waves.

d. all of the above.

35. The condition in which the heart beats faster than normal is called: (A)

a.