A&P Final Mastering questions (Heart)

What is the source of ATP for cardiac muscle contraction? glycolysis creatine phosphate cellular respiration stored ATP

cellular respiration

What causes heart sounds? opening of heart valves heart valve closure pressure of blood in the ventricles blood flowing from the atria into the ventricles

heart valve closure

Which of the following terms refers to a lack of oxygen supply to heart muscle cells? ischemia functional syncytium infarction embolism

ischemia

Which valve is located between the right atrium and ventricle? pulmonary semilunar valve aortic semilunar valve tricuspid valve mitral valve

tricuspid valve

Which of the following is not a difference between the left and right ventricles? The walls of the left ventricle are thicker than the walls of the right ventricle. The left ventricle is a more powerful pump than the right ventricle. The left ventricle pumps blood to the systemic circuit, while the right ventricle pumps blood to the pulmonary circuit. The left ventricle receives a smaller percentage of coronary blood supply than the right ventricle.

The left ventricle receives a smaller percentage of coronary blood supply than the right ventricle.

What is afterload? contractility of cardiac muscle cardiac reserve degree of stretch of the heart muscle back pressure exerted by arterial blood

back pressure exerted by arterial blood

The heart has _____ chambers and _____ valves. 2; 2 4; 4 2; 4 4; 2

4; 4

In a healthy individual which of the following would be low? Stroke volume Contractility Afterload Preload

Afterload

Which of the following is not a difference between cardiac and skeletal muscle? Cardiac muscle cells contain more mitochondria than do skeletal muscle cells. Cardiac muscle cells quickly die in the absence of oxygen; skeletal muscle cells are better able to adapt to oxygen deficiency. Cardiac muscle does not use the sliding filament mechanism for contraction; skeletal muscle does. The plasma membranes of cardiac muscle cells interlock, but skeletal muscle fibers are independent.

Cardiac muscle does not use the sliding filament mechanism for contraction; skeletal muscle does.

Which of the following would increase heart rate? Parasympathetic stimulation Cold temperature Low metabolic rate Epinephrine

Epinephrine

Which of the following does not deliver blood to the right atrium? Inferior vena cava Pulmonary veins Superior vena cava Coronary sinus

Pulmonary veins

Which is correctly matched? Diastole: contraction period Systole: relaxed period Stroke volume: amount of blood pumped out by each ventricle in one minute Quiescent period: total heart relaxation between heartbeats

Quiescent period: total heart relaxation between heartbeats

Which of the following is NOT a factor that regulates stroke volume? afterload contractility heart rate preload all the factors above regulate stroke volume

all the factors above regulate stroke volume

The first heart sound (the 'lub' of 'lub-dup') is caused by: closure of the semilunar valves. opening of the atrioventricular valves. closure of the atrioventricular valves. opening of the semilunar valves.

closure of the atrioventricular valves.

A premature ventricular contraction is classified as a(n): ectopic focus. extrasystole. heartblock. arrhythmia.

extrasystole.

Which heart chamber sends deoxygenated blood to the lungs? left atrium right atrium left ventricle right ventricle

right ventricle

The heart's pacemaker is the: atrioventricular bundle. atrioventricular node. Purkinje fibers. sinoatrial node.

sinoatrial node.

The QRS complex on an electrocardiogram represents: atrial repolarization. ventricular repolarization. ventricular depolarization. atrial depolarization.

ventricular depolarization.

What does the T wave of the electrocardiogram represent? atrial repolarization ventricular depolarization atrial depolarizaton ventricular repolarization

ventricular repolarization