Question

the electrical impulse is delayed in the av node before propagating to the av bundle (of his). during this delay the ______ contract.
multiple choice
right atrium and right ventricle
left ventricle and aorta
right atrium and left atrium
left atrium and left ventricle

Explanation:

The electrical impulse starts in the sino - atrial (SA) node. It then travels to the atrioventricular (AV) node. Before the impulse propagates to the AV bundle (of His), there is a delay in the AV node. This delay allows the atria (both right and left atrium) to contract first. The contraction of the atria helps in filling the ventricles with blood more effectively. The other options are incorrect as the ventricles (right ventricle, left ventricle) and aorta do not contract during this AV - nodal delay.

Answer:

C. right atrium and left atrium