Exam 9: Cardiac Physiology

Increasing stroke volume ____________________ cardiac output.

The AV and semilunar valves are never open at the same time.

Unique voltage-gated Na⁺ channels in pacemaker cells that open when the membrane becomes more negative (hyperpolarizes) and bring about the initial depolarization in the pacemaker potential are called ________ channels.

The addition of ACh to the SA node would decrease the number of T waves observed per minute on an ECG.

Use this figure to answer the corresponding questions. -Identify the location(s) where the cell's permeability to Na⁺ is the greatest. a.between 1 and 2 b.between 2 and 3 c.between 2 and 4 d.between 3 and 4 e.4 only

Describe the way in which high blood pressure and a defective semilunar valve can make it more difficult for the heart to pump blood into the systemic circulation and how these factors can decrease cardiac output.Include the following in your answer: afterload, period of isovolumetric contraction, stenosis, and blood flow resistance.

The ECG allows one to detect the electrical activity of a single contractile cell in the heart, but it does not show any mechanical events such as contraction and relaxation.

Indicate the effects of sympathetic and parasympathetic stimulation on the heart using the following answer code: a.caused by sympathetic stimulation b.caused by parasympathetic stimulation c.not brought about by sympathetic or parasympathetic stimulation -Decreases the contractility of the ventricular muscle

The plateau phase of the action potential in a contractile cardiac muscle cell occurs as a result of activation of slow Ca²⁺ channels.

During congestive heart failure, the heart is pumping out deoxygenated at a faster rate than it is pumping out oxygenated blood.

Describe the generation of pacemaker action potentials and then track the resulting impulse through the cardiac conduction system.Include the names of specific types of channels in the first part of your answer.

Match cardiovascular feature with correct characteristic. a.angina pectoris b.embolus c.atherosclerosis d.thrombus -Freely floating clot

A heart rate of more than 100 beats per minute is called ________, while a heart rate less than 60 beats per minute is called ___________.

Twelve complete ECG patterns are recorded over 10 seconds, which means the heart rate is ____ beats per minute.

The wall of the left ventricle is thicker than the wall of the right ventricle, which allows the

The ____________________ is the normal pacemaker of the heart.

The dicrotic notch on the aortic pressure wave is due to a disturbance caused by the closure of the ______ valve.

Match EKG feature with the correct characteristic. a.P wave b.QRS complex c.T wave d.PR interval e.TP interval f.ST segment -Time during which ventricles are filling

Match the characteristic with the appropriate term(s). a.tricuspid valve b.bicuspid valve c.mitral valve d.pulmonary valve e.aortic valve f.all heart valves g.aortic valve; pulmonary valve h.bicuspid valve; mitral valve i.tricuspid valve; bicuspid valve j.tricuspid valve; pulmonary valve k.mitral valve; aortic valve l.fibrous skeleton m.chordae tendineae n.oxygenated blood o.deoxygenated blood -Prevents blood from leaving the left ventricle during isovolumetric contraction

Not all forms of cholesterol are equally harmful to the heart.