61) If the beating heart makes a "lub-dup" sound, the "dup" sound is caused by
A) the apex of the heart hitting the anterior chest wall.
B) a stenotic atrioventricular valve.
C) the large force of the contracting ventricles.
D) vibrations that result from the semilunar valves slamming shut.
62) The base of the aorta derives from which of these "original" heart chambers in the embryo?
A) sinus venosus
B) atrium
C) ventricle
D) bulbus cordis
63) Destruction of which structure will result in electrical signals traveling to only one ventricle?
A) atrioventricular bundle
B) bundle branch
C) internodal pathway
D) sinoatrial node
64) Clinically, the posterior interventricular artery is referred to as the
A) left artery ascending.
B) left artery descending.
C) posterior descending artery.
D) posterior ascending artery.
65) Of the three layers of the heart wall, the layer that contains the cardiac muscle is the
A) epicardium.
B) visceral layer of serous pericardium.
C) myocardium.
D) endocardium.
66) Cells of the subendocardial conducting network
A) are larger and have fewer myofilaments than other cardiac cells.
B) are nonconducting cells that electrically insulate the bundle branches of the interventricular septum.
C) are pacemaker cells located in the SA node that initiate each heartbeat.
D) are sensory cells that monitor the stretch of the myocardium to prevent overexpansion by high blood pressure.
67) There is a foramen ovale in the skull and another one in the heart. The foramen ovale in the heart gives rise to the
A) openings between the atria and ventricles.
B) openings between the ventricles.
C) fossa ovalis.
D) aortic semilunar valve.
68) Insertion of a stent to treat coronary artery disease (CAD)
A) involves grafting a portion of the saphenous vein that contains the stent into the occluded artery.
B) is accomplished by laparoscopic incision at the jugular notch.
C) occurs through a catheter inserted in the femoral artery.
D) requires open heart surgery.
69) Pericarditis can lead to all of the following
except
A) excess fluid in the pericardial cavity.
B) pericardial friction rub.
C) adhesions.
D) a myocardial infarction.
70) The "heartstrings" are
A) cusps of the atrioventricular valves.
B) chordae tendineae.
C) trabeculae carneae.
D) papillary muscles.