Exam 8: Cardiac Physiology

The average resting heart rate is normally established by the rhythm of the AV node.

Describe generation of pacemaker action potentials and the cardiac conduction pathway.

Which of the actions is done by the semilunar valves

The refractory period in cardiac muscle is much shorter than the refractory period in skeletal muscle to ensure that the heart can quickly be restimulated to produce alternate periods of contraction and relaxation.

Which heart chamber has the greatest workload

The long refractory period of cardiac muscle prevents tetanic contractions of the heart.

The ECG is an actual recording of cardiac electrical activity.

The ____________________ is the difference between cardiac output at rest and maximal CO.

Why the heart does not require the nervous system to initiate contraction events

Which of these statements describes the systemic circulation

Hypertension decreases the afterload and increases the preload.

The heart is posterior to the sternum.

Which of the following is the cranial nerve of the parasympathetic nervous system that signals the heart

Match the EKG features, labelled a. through f., with their correct characteristic. -ventricular repolarization

Match the terms, labelled a. through f., with the descriptions. (Options may be used more than once or not at all.) -The volume of blood ejected by each ventricle each minute is known as the _____.

Match the anatomical structures, labelled a. through e., with the heart characteristics. (Options may be used more than once or not at all.) -overcomes the afterload of the circuits

Match the factor involved in the initiation and spread of cardiac excitation, labelled a. through d. with the description. (Options may be used more than once or not at all.) -allows the impulse to spread from cell to cell

According to the Frank-Starling law of the heart, the greater the stroke volume, the smaller the subsequent end-diastolic volume will be, because as more blood is squeezed out, the heart cannot fill as completely during the next diastole.

The second heart sound occurs when the semilunar valves close.What does this mark

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.