18. The Heart

When the pressure inside the ventricle causes the atrioventricular valve to close and the semilunar valve to open, which statement about the heart is true?

For the atrioventricular valves to be open, the pressure in the ventricles must be:

What event immediately follows the closure of the atrioventricular valves and coincides with the onset of ventricular systole?

During which following phase (or phases) of the cardiac cycle is the blood volume in the ventricles constant?

If the pressure in the ventricles is higher than in the atria, which of the following statements must be true?

I. The atrioventricular valves are closed.

II. The semilunar valves are open. 

III. The ventricles are in systole.

True or False: if false, choose the answer that best corrects the statement.

Ventricular filling is defined as the period that the atria are in systole.

Using a stethoscope, you listen to the heart of a patient in their early forties. You hear a clear 1st heart sound (lub), but the second heart sound is muffled and followed by a whooshing noise. What structure could be dysfunctional in this patient?

During which phase or phases of the cardiac cycle does the ventricular pressure change the least?

During which phase of the cardiac cycle do you hear the second heart sound?

You are listening to the heart through a stethoscope. When you hear the first heart sound, which of the following options correctly matches the structure to the pressure change that would be most responsible for producing that sound?

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

a. Systole is the contraction portion of the cardiac cycle and diastole is the relaxation portion.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

b. Atrial systole is responsible for ejecting most of the blood into the ventricles during the ventricular filling phase of the cardiac cycle.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

d. The ventricular ejection phase generally correlates with the S-T segment and the T wave on the ECG.

Which chamber generates the highest pressure during systole?

a. Right atrium

b. Right ventricle

c. Left atrium

d. Left ventricle

Fill in the blanks: The first heart sound is called______and it is caused by the closing of the_____valves. It occurs at the beginning of the_____phase of the cardiac cycle. The second heart sound is called_____and it is caused by the closing of the______ valves. It occurs at the beginning of the_____phase of the cardiac cycle.

Cardiac output is equal to:

a. end-diastolic volume minus end-systolic volume.

b. heart rate multiplied by stroke volume.

c. stroke volume divided by end-diastolic volume.

d. heart rate multiplied by preload.

Fill in the blanks: An increase in preload causes a/an_____ in stroke volume in accordance with the_____ law. An increase in afterload causes a/an ______in stroke volume. An increase in contractility causes a/an______in stroke volume.

Which of the following statements is false?

a. The sympathetic nervous system releases epinephrine and norepinephrine, which are positive chronotropic and inotropic agents.

b. The endocrine system regulates cardiac output through chronotropic and inotropic hormones and through hormones that regulate water balance.

c. The parasympathetic nervous system releases acetylcholine and epinephrine, which are strongly negative inotropic agents.

d. Factors such as electrolyte concentrations, body temperature, and age all affect cardiac output.

You are an athletic trainer who is working with someone planning to run a marathon. Your trainee tells you to give him a workout that will make his heart 'beat faster than ever before.' What do you tell him about the effects of too rapid a heart rate?