Module 2

Signals leave the AV node and descend along this structure toward the apex

AV bundle

Which of the following belong to the pulmonary circuit

Pulmonary arteries and pulmonary veins

The pulmonary circuit is supplied by what side of the heart?

Right side (right ventricle)

The pacemaker that determines the heart rate

Sinuatrial (SA) node

Distributes the electrical excitation to the ventricles

Subendocardial conducting network (Purkinje fibers)

Why is cardiac muscle not prone to fatigue

it makes little use of anaerobic fermentation or the oxygen debt mechanism

The plateau in the action potential of cardiac muscle results from the action of _________

slow Ca2+ channels

The electrical gateway to the ventricles

Atrioventricular (AV) node

The long plateau in the action potential observed in cardiomyocytes is probably related with ________ staying longer in the cytosol

Ca2+

Place the following vessels in the order through which blood would pass, beginning with blood entering the systemic circuit after exiting the heart

Conducting arteries > distributing arteries > resistance arteries > Arterioles > Capillaries > Post-capillary venules > Muscular venules > Medium venules > Venous sinuses > Large veins

Which vessels have the thickest tunic media

Large arteries

Atrial depolarization causes the ___________

P wave

Opening and closing of the heart valves is caused by __________

Pressure gradients

Which of the following is a feature shared by cardiac muscle and skeletal muscle

muscle fiber striations

Blood usually passes through one network of capillaries from the time it leaves the heart until the time it returns, but there are exceptions, notably the __________

portal systems and anastomoses