Cardiac Physiology

The heart lies in the left half of the thoracic cavity

• True

• False

Which of the following is the proper sequence of cardiac excitation?

• SA node-AV node-atrial myocardium-bundle of

  His-Purkinje fibers-ventricular myocardium

• SA node-atrial myocardium-AV node-bundle of

  His-ventricular myocardium-Purkinje fibers

• SA node-atrial myocardium-ventricular myocardium-AV node-bundle of His-Purkinje fibers

• SA node-atrial myocardium-AV node-bundle of

  His-Purkinje fibers-ventricular myocardium

Sympathetic stimulation of the heart

• increases the heart rate

• increases the contractility of the heart muscle

• shifts the Frank–Starling curve to the left

• Both a and b

• All of the above

It received O2 poor blood from the venae cavae

• Left atrium

• Right Atrium

• Left ventricle

• Right ventricle

Pumps O2 rich blood into the aorta

• Left atrium

• Right Atrium

• Left ventricle

• Right ventricle

pumps O2-poor blood

into the pulmonary artery

• Left atrium

• Right Atrium

• Left ventricle

• Right ventricle

receives O2-rich blood

from the pulmonary veins

• Left atrium

• Right Atrium

• Left ventricle

• Right ventricle

prevents backflow of blood from the ventricles to the atria

• AV valves

• Semilunar valves

prevents backflow of

blood from the arteries

into the ventricles

• AV valves

• Semilunar valves

The first heart sound is associated with the closing of

the _______(AV/semilunar) valves and signals the onset of ____________(systole/

diastole), whereas the second heart sound is associated with

closing of the _________(AV/semilunar) valves and signals the onset of

_____________(systole/diastole).

(a)