Question

Name the phase of the cardiac cycle in which the auricles contract.

Answer 1

Cardiac cycle:

1. The sequence or the repeating process of systole (contraction) and diastole (relaxation) of the heart chambers is referred to as a cardiac cycle.
2. The duration of a cardiac cycle is 0.8 seconds.

Systole and Diastole:

1. The period of contraction of the auricles and ventricles is called systole.
2. The period of relaxation of the auricles and ventricles is called diastole.

Auricular systole:

1. The phase in which the auricles contract is known as the auricular systole.
2. It is the first phase of the cardiac cycle.
3. The auricular systole starts by receiving the impulses from the Sino-Atrial node (SA node).
4. It occurs with the opening of bicuspid and tricuspid valves as the blood moves into the ventricles.
5. The duration of the auricular systole is 0.1 seconds.