Which statement is true about systole? a. At the onset of ...

[Mr. Wonderful]

Which statement is true about systole?
 
  a. At the onset of systole, the pressure in the ventricles is less than that in the atria.
  b. During this phase, the mitral and tricuspid valves close, producing the first heart sound.
  c. Blood flows from the atria into the ventricles.
  d. The atria contract sending blood into the ventricles.

Question 2

Capillaries are
 
  a. large vessels that transport systemic blood under high pressure to the tissues
  b. the smallest branch of the arterial system
  c. thin-walled vessels permeable to small molecular substances
  d. vessels that transport blood from the tissues to the heart

[BUTTHOL369]

Answer to Question 1

B
At the onset of systole, an increase in ventricular pressure causes the mitral and tricuspid valves to close. The closing of these valves produces the first heart sound or S1.

Answer to Question 2

C
Large vessels that transport systemic blood under high pressure to the tissues are arteries. Arterioles are the smallest branch of the arterial system. Thin-walled vessels that are permeable to small molecular substances are capillaries. Vessels that transport blood from the tissues to the heart are veins.

[Mr. Wonderful]

Gracias!

[debra928]

Excellent