Chapter 18 A&P

Complications related to arteriosclerosis account for roughly ________ percent of deaths in the United States. 60 20 50 25 30

50

Pacemaker cells isolated from the SA node generate action potentials at ________ beats per minute. 80-100 140-180 40-60 100-140 20-40

80-100

The superior portion of the heart where major blood vessels enter and exit is the left border. apex. right border. base. inferior border.

base

The bicuspid, or mitral, valve is located between the right atrium and right ventricle. where the venae cavae join the right atrium. in the opening of the aorta. between the left atrium and left ventricle. in the opening of the pulmonary trunk.

between left atrium and left ventricle

In cardiac muscle, the fast depolarization phase of the action potential is the result of ________ membrane permeability to ________ ions. increased; sodium increased; chloride decreased; calcium increased; potassium decreased; sodium

increased; sodium

The ________ deliver(s) blood to the myocardium. superior vena cava left coronary artery right coronary vein right coronary artery and left coronary artery right coronary artery

left and right

Blood returning to the heart from the pulmonary circuit first enters the left atrium. left ventricle. right atrium. conus arteriosus. right ventricle.

left atrium

Blood is supplied to the left atrium by the pulmonary arteries. brachiocephalic artery. phrenic arteries. left coronary artery. right coronary artery.

left coronary artery

The circumflex branch and the anterior interventricular artery are branches of the right coronary artery. aorta. left coronary artery. coronary sinus. interventricular artery.

left coronary artery

Most of the mass of the heart lies to the ________ the midline. area above right of left of None of these answers are correct. area below

left of

When the semilunar valves close, the AV valves then All of the answers are correct. open. None of these answers are correct. make the third heart sound. close.

open

Contractions of the papillary muscles eject blood from the ventricles. eject blood from the atria into the ventricles. close the atrioventricular valves. prevent the atrioventricular valves from reversing into the atria. close the semilunar valves.

prevent the atrioventricular valves from reversing into the atria

During the T wave of the electrocardiogram, the ventricles are electrically ________ and functionally ________. depolarizing,; relaxing repolarizing; relaxing neutral; at rest repolarizing; contracting depolarizing; contracting

repolarizing; relaxing

Blood returning to the heart from the systemic circuit first enters the conus arteriosus. right ventricle. left ventricle. left atrium. right atrium.

right atrium

A faster-than-normal heart rate is called premature contractions. fibrillation. tachycardia. bradycardia. None of these answers are correct.

tachycardia

Tetanic muscle contractions don't occur in a normal cardiac muscle because the refractory period lasts until the muscle relaxes. neural stimulation is lacking. the refractory period ends before the muscle reaches peak tension. cardiac muscle tissue contracts on its own. potassium channels outnumber sodium channels.

the refractory period lasts until the muscles relaxes

The T wave on an ECG tracing represents ventricular contraction. atrial repolarization. atrial depolarization. ventricular repolarization. ventricular depolarization.

ventricular repolarization.

At a heart rate of 60 beats/minute, a cardiac cycle lasts more than a second. 1 second. 60 seconds. 370 milliseconds. less than a second.

1 second

Which parts of the following statement are true? The AV node delivers the stimulus to the AV bundle, located within the interventricular septum. The first part of the statement is true but the second part is false. Both parts of the statement are false. The first part of the statement is false but the second part is true. Both parts of the statement are true.

both parts of the statement are true

Most of the middle layer in the heart wall is composed of fibrocytes. epithelial cells. chondrocytes. cardiac muscle cells. smooth muscle cells.

cardiac muscle cells

The term used to describe fluid collecting in the pericardial cavity that restricts the movement of the heart is known as pericarditis. pleural effusion. mitral valve prolapse. cardiac tamponade. cardiomyopathy.

cardiac tamponade

Drugs that block the beta-one adrenergic receptors will decrease heart rate. increase contractility. increase heart rate. increase cardiac output. decrease the end-systolic volume.

decrease heart rate

The ________ lines the chambers of the heart, covers the heart valves, and is continuous with the endothelium. parietal pericardium myocardium visceral pericardium epicardium endocardium

endocardium

The pulmonary veins carry blood to the intestines. heart. lungs. liver. brain.

heart

David suffers from a prolapsed mitral valve. This condition would cause increased effort by the left ventricle and regurgitation. regurgitation. increased effort by the right ventricle and regurgitation. increased effort by the right ventricle. increased effort by the left ventricle.

increased effort by the left ventricle and regurgitation.