Question

- Fill in the blanks on the blood flow pathway from the systemic circulation to the heart, to the lungs, and then back to the heart and systemic circulation. (Do not include valves)

Vena Cava > Right Atrium > __________ (chamber) > Pulmonary Trunk > Lungs > _____________(vessel) > _____________(chamber) > Left Ventricle > _____________(vessel).

- (Fill in the blanks) In comparison to skeletal muscle action potentials, cardiac muscle action potentials have a plateau before they repolarize completely. this is due to _____________ channels closing slowly and _____________ channels opening slowly. The upswing phase (depolarization) of cardiac muscle action potentials is described as the pacemaker potential. This is due to opening of voltage-gated _____________ and _____________ channels.

Answer 1

Question 1:

Vena Cava > Right Atrium > Right ventricle (chamber) > Pulmonary Trunk > Lungs > Pulmonary veins (vessel) > Left atrium (chamber) > Left Ventricle > Aorta (vessel).

Question 2 :

In comparison to skeletal muscle action potentials, cardiac muscle action potentials have a plateau before they repolarize completely. This is due to K+ channels closing slowly and Ca2+ channels opening slowly. The upswing phase (depolarization) of cardiac muscle action potentials is described as the pacemaker potential. This is due to opening of voltage-gated Calcium and closure of K+ channels.