At what point in the figure do the atrioventricular valves close? ...

[acc299]

At what point in the figure do the atrioventricular valves close?
 
  a. B c. E
  b. D d. F

Question 2

When does the atrial kick begin?
 
  a. Just before atrial systole
  b. During atrial repolarization
  c. During the impulse delay in the atrioven-tricular node
  d. Simultaneously with ventricular excitation

[AngeliqueG]

Answer to Question 1

ANS: C
The atrioventricular valves close at the beginning of ventricular systole. See Figure 9-22.

Answer to Question 2

ANS: C
As the impulse travels through the atrioventricular node, there is a 100-ms delay in conduction. This delay is important because it allows the atria to become fully depolarized and contract be-fore ventricular excitation begins. This allows the atria to contract and empty, which has been dubbed atrial kick, contributing to optimal ventricular filling.

[acc299]

Excellent

[ultraflyy23]

Thanks for the timely response, appreciate it