The second heart sound (the “dup” of “lub-dup”) is caused by the __________.

The role of the atrioventricular node (AV node) is to __________.

The noncontractile cardiac muscle cells that initiate their own depolarization and cause depolarization of the rest of the heart are called __________.

The absolute refractory period refers to the time during which __________.

The normal pacemaker of the heart is the __________.

Freshly oxygenated blood is delivered to the __________, and then it passes into the __________ to be pumped to the body tissues (systemic circuit).

The coronary arteries arise from the __________.

The contractile cardiac muscle fibers of the myocardium behave as a single, coordinated unit called a __________.

What part of the heart is considered the systemic circuit pump?

What is the correct sequence of electrical current flow through the heart wall?

Which valve is most often faulty in the heart?

When the mitral valve closes, it prevents the backflow of blood from the __________.