Heart Valves

The coordinated action of chordae tendineae, papillary muscles, and ventricular walls prevent the cusps of the mitral valve from inverting into the atria. How is this achieved? a. Papillary muscles anchor the chordae tendineae to the ventricular wall to create tension and prevent the cusps inverting into the atria. b. Papillary muscles contract and pull the cusps closer to the ventricular wall to prevent cusps inverting into the atria.

A.

Which of the following is responsible for generating the first heart sound, and the second heart sound? a. Closure of the AV valves, then closure of the semilunar valves. b. Closure of the semilunar valves, then closure of the AV valves.

A.

AV or Semilunar: Attached to chordae tendinae

AV

AV or Semilunar: tethered to papillary muscles

AV

When you palpate (feel) an arterial pulse, what are you feeling? a. The movement of blood through the artery. b. The propagating pressure wave through the artery. c. Vibrations caused by closure of the semilunar valve.

B.

In the ECG of a normal cardiac cycle, the T wave corresponds to: a. Depolarization of the atria. b. Depolarization of the ventricles. c. Repolarization of the atria. d. Repolarization of the ventricles.

D.

The QRS complex in the ECG occurs: a. After the first heart sound is heard. b. At the same time as the first heart sound is heard. c. At the same time as the second heart sound is heard. d. Before the first heart sound is heard.

D.

T or F: A heart sound is heard when a heart valve opens

F

T or F: Semilunar valves close when the ventricles reach their maximum filling capacity

F

What is the first phase of systole?

Isovolumetric Phase In this phase, the ventricles contract against closed valves on each side. As a result, ventricular pressure rises rapidly.

What happens when aortic valve opening becoming narrowed (aortic stenosis)?

Narrowed aortic valve impedes the blood flow from the ventricles to the aorta during ventricular contraction, causing resistance and change in stroke volume. To compensate this, the left ventricular muscle becomes thicker.

AV or Semilunar: Both valves contains three cusps

Semilunar

T or F: A heart sound is heard when a heart valve closes

T

T or F: The first heart sound is due to closure of the mitral and tricuspid valves

T

The second heart sound can often be heard as two separate sounds (but in close succession). Can you think of a reason why?

This sound is often split as the aortic valve closes slightly before the pulmonary valve.