Ventricular systole occurs approximately between the S 1 and S 2 heart
sounds and diastole between S 2 and S 1. Occasionally, a low, rumbling third
heart sound may be heard during diastole and is attributable to ventricular
filling. Stenosis or insufficiency of the valves produces turbulence and
backflow, respectively, which are heard as murmurs. None of the other
combinations(answers a, b, d, e)are correct.
360.The answer is d.(Moore and Dalley, pp 322–323.)The esophageal
hiatus, in addition to allowing passage of the esophagus, also passes the
anterior and posterior vagal trunks. The aortic hiatus carries the aorta, the
thoracic duct (answer e),and occasionally, an azygos (answer a)or hemi-
azygos(answer b)vein. Usually, the azygos and hemiazygos veins (answer
c)either pass lateral to or through a crus of the diaphragm along with the
respective left and right sympathetic chains. The phrenic nerves usually
penetrate the diaphragm to gain access to the inferior surface; however, the
right phrenic may accompany the inferior vena cava through the caval
hiatus.
361.The answer is a.(Sadler, pp 177–178.)The girl has tetralogy of
Fallot. Since the girl is 3 months old it is very unlikely that she would have
survived transposition of the great vessels (answer c)without surgical
intervention. Tetralogy of Fallot consists of three congenital conditions and
a fourth acquired condition as a consequence of the first three. Tetralogy of
Fallot consists of an overriding aorta that receives blood from both ventri-
cles, pulmonary stenosis that tends to keep blood out of the lungs, and a
ventricular septal defect (otherwise the aorta could “override”). As a conse-
quence of the three conditions, the right ventricle tends to hypertrophy
since it has to pump blood notonly into the lungs, but also through the
aorta to the rest of the body. Since the girl has normal blood pressure in her
upper and lower limbs, coarctation of the aorta (answer b)is unlikely. In
addition simple aortic stenosis (answer d)is unlikely to produce hypertro-
phy of the right ventricle which appears to be present. A ventricle septal
defect(answer e)is just part of the problem.
362.The answer is b. (Moore and Dalley, pp 113, 115.)Normally the
pleural space extends inferiorly about two additional ribs inferior to the lung
at each location, thus at the midaxillary line the caudal portion of the lung
normally lies at about the eight intercostal space and the pleural space
488 Anatomy, Histology, and Cell Biology