The semilunar (pulmonary and aortic) valves do which of the ...

[Alainaaa8]

The semilunar (pulmonary and aortic) valves do which of the following?
 
  a. Cause almost the entire afterload for the ventricles.
  b. Consist of two half-moon or cres-cent-shaped cusps.
  c. Prevent arterial backflow during ventricu-lar relaxation.
  d. Separate the ventricles from their arterial outflow tracts.

Question 2

Narrowing of the mitral valve (mitral stenosis) results in which of the following?
 
  a. Increased afterload on left ventricle
  b. Increased preload on right ventricle
  c. Increased pulmonary congestion
  d. Systemic hypertension

[peter]

Answer to Question 1

ANS: D
A set of semilunar valves separates the ventricles from their arterial outflow tracts (Figure 9-3). Consisting of three half-moonshaped cusps attached to the arterial wall, these valves prevent backflow of blood into the ventricles during diastole (or when the heart's chambers fill with blood).

Answer to Question 2

ANS: C
Stenosis is a pathologic narrowing or constriction of a valve outlet, which causes increased pres-sure in the affected chamber and vessels. Both conditions affect cardiac performance. For exam-ple, in mitral stenosis, high pressures in the left atrium back up into the pulmonary circulation. This can cause pulmonary edema.