Author Question: The period of time during the cardiac cycle when cells cannot respond to a stimulus, no matter how ... (Read 53 times)

debasdf · **on:** Jun 25, 2018

The period of time during the cardiac cycle when cells cannot respond to a stimulus, no matter how strong, is the relative refractory period.

Indicate whether the statement is true or false

Question 2

Which of the following are semilunar valves?

a. Aortic and pulmonic
b. Aortic and tricuspid
c. Pulmonic and mitral
d. Tricuspid and mitral

Edwyer · **Reply #1 on:** Jun 25, 2018

Answer to Question 1

F
During the absolute refractory period, the cell will not respond to further stimulation. This means that the myocardial working cells cannot contract and the cells of the electrical conduction system cannot conduct an electrical impulse, no matter how strong the stimulus.

Answer to Question 2

A
The pulmonic and aortic valves are semilunar (SL) valves. The semilunar valves prevent backflow of blood from the aorta and pulmonary arteries into the ventricles.