Exam 7: Cardiac Physiology

The condition in which the pericardial sac becomes distended with excess fluid to the point that it impinges upon cardiac filling is known as ____________________.

The action potential spreads through the atria by gap junctions,but there are no gap junctions present in the ventricles,so the impulse must be propagated throughout the ventricular myocardium by the bundle of His and Purkinje system.

Most blood flow through the coronary vessels occurs during ventricular systole when the heart is driving blood forward.

Which of the following is the normal pacemaker of the heart?

Angina pectoris develops from the abundance of oxygen of blood in the coronary circulation.

Which nerves to the heart alter cardiac output by increasing heart rate and increasing contractility?

An increase in cardiac sympathetic activity ____________________ the stroke volume.

The ESV of the heart averages about 140 mL.

The ____________________ is the volume of blood pumped by each ventricle/minute.

Indicate which ion is involved in each event being described by using the answer code (options may be used more than once or not at all): -Inactivation of _____ channels brings about the slow drift of membrane potential to threshold in the cardiac autorhythmic cells.

Indicate which factor involved in the initiation and spread of cardiac excitation is being identified by using the answer code (options may be used more than once or not at all): -allows the impulse to spread from cell to cell

Indicate which ion is involved in each event being described by using the answer code (options may be used more than once or not at all): -Parasympathetic stimulation increases the permeability of the SA node to _____,whereas sympathetic stimulation decreases the permeability to this same ion.

Which statement concerning the AV node is correct?

Indicate which pressure relationship exists during the time in question by using the answer code (options may be used more than once or not at all): -during isovolumetric ventricular contraction

An increase in parasympathetic activity ____________________ the rate of depolarization of the SA node.

Complete the following statements by using the answer code (options may be used more than once or not at all): -The number of times the heart contracts each minute is the_____.

____________________ is the insufficient circulation of oxygenated blood to cardiac muscle in order to maintain its aerobic metabolism.

MATCHING Match the term with the correct characteristic by using the answer code: -muscle mass that becomes excited and contracts as a unit

Indicate which factor involved in the initiation and spread of cardiac excitation is being identified by using the answer code (options may be used more than once or not at all): -delays conduction of the impulse

PAF is released from the ____________________ lining of vessels.