Exam 9: Cardiac Physiology

According to the Frank-Starling law of the heart, the shorter the initial length of the cardiac muscle fibers prior to contraction, the more forceful will be the subsequent contraction because the fibers are already partially contracted.

Although not seen on an ECG, the period of isovolumetric contraction would occur nearest which deflection of an ECG?

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

Match heart characteristic with correct anatomical structure. a.tricuspid valve b.myocardium c.aortic semilunar valve d.AV node e.sinoatrial node -Contraction of this generates blood pressure

Use the following answer code to compare the magnitude of the items in question. a.A is greater than b.b.B is greater than a.c.A and B are equal or nearly equal. -a.Volume of blood in the left ventricle when the aortic valve opens B.Volume of blood in the left ventricle when the aortic valve closes

A lumen that contains blood with a comparatively higher concentration of oxygen is in the

Increased EDV results in decreased stroke volume, and increased stroke volume results in increased ESV.

Use the following answer code to compare the magnitude of the items in question. a.A is greater than b.b.B is greater than a.c.A and B are equal or nearly equal. -a.Volume of blood in the ventricles at the onset of isovolumetric ventricular contraction B.Volume of blood in the ventricles at the end of isovolumetric ventricular contraction

Use this figure to answer the corresponding questions. -This graph shows the electrical activity for one of the heart's a.contractile cells b.pacemaker cells c.autorhythmic cells d.contractile and autorhythmic cells e.pacemaker and autorhythmic cells

The direction of impulses through the conduction system of the heart is normally

Contraction of the spirally arranged cardiac muscle fibers produces a wringing effect for efficient pumping.

The electrocardiogram is most useful in determining which component of cardiac output?

L-type calcium channels allow the refractory periods in the heart's contractile cells to be about as long as the cells' relaxation periods.

The function of the ventricular conduction system of the heart is to

Indicate which valve abnormality is being described using the answer code below. a.valvular stenosis b.valvular insufficiency -Produces a "gurgling" murmur

A(n) ____________________ is a clot attached to the wall of a vessel.

During heart failure,

Which of the following criteria must be met for the heart to function efficiently?

The AV valve controls the amount of blood entering the atrium from the venous system.

Which of the following is not associated with an increase in stroke volume?