Exam 22: A: Physiology of the Cardiovascular System

The first Korotkoff sound indicates the diastolic blood pressure.

The normal rhythm of the heart is set by the ectopic pacemaker.

An increase in arterial blood pressure causes an increase in parasympathetic impulses to the heart and blood vessels.

In a healthy adult,blood pressure at the union of the vena cavae and right atrium is about 80 mm Hg.

The popliteal pulse point is found on the anterior surface of the elbow.

The difference between systolic and diastolic pressures is termed pulse pressure.

The repolarization of the atrium cannot be seen on the ECG because the size of the QRS complex blocks it out.

Exercise has little effect on cardiac output.

During isovolumetric ventricular contraction,the semilunar valves are closed but the AV valves are open.

During the normal cardiac cycle,there is never a time when both the atria and ventricles are relaxed.

Because of the high concentration of protein in plasma,a decrease in the red blood cell count will cause an increase in blood viscosity.

The conduction system of the heart is composed of specialized motor neurons that are embedded in the heart muscle.

Parasympathetic control of the heart depends on the glossopharyngeal nerve (cranial nerve IX).

Venous valves would not be necessary in the jugular veins of the neck.

Because of their small diameter,capillaries account for almost all the resistance to blood flow in the circulatory system.

As the action potential enters the AV node by way of the internodal bundles,the speed of the conduction increases to stimulate ventricular contraction.

An increase in blood temperature tends to slow down heart rate.