Heart Quiz Questions

Acetylcholine

Decreases the rate of depolarization of pacemaker cells in the SA node

A patient has an end diastolic volume of 100 mL, an end systolic volume of 40 mL, and a heart rate of 100 bpm. What is the ejection fraction?

60%

In an ECG, blood is flowing from the atria to the ventricles

Between the P wave and just after the beginning of the QRS complex

Ralph has a resting heart rate of 60 beats per minute, and end diastolic volume of 100 mL, and an end systolic volume of 40 mL. What is his cardiac output?

3600 mL/min

When the ventricles are ejecting blood, pressure is lowest in the

Atria

Beta blockers selectively block beta-1 adrenergic receptors in the heart.  These medications would

Decrease the rate of depolarization of pacemaker cells in the SA node, Decrease calcium release in cardiomyocytes, Decrease cardiac output

If more blood fills the left ventricle prior to a heartbeat, stroke volume will

Increase

If electrical signals from the atria do not reach the ventricle

The rate of ventricular contraction will slow

In cardiac muscle, the absolute refractory period lasts until calcium is pumped away from the myofibrils.  This ensures that

The heart relaxes between heart beats

When does the left ventricle contain the most blood?  (If two answers are equal, choose both)

A and B

Many choice: Stimulation by the sympathetic nervous system increases

Heart rate, Stroke volume, EDV, Contractility

Atropine (blocks muscarinic ACh receptors)

Increases the rate of depolarization pacemaker cells in the SA node and increases HR

During diastole, pressure is lowest in the

Ventricles

After bleeding, heart rate increases to restore cardiac output. This is necessary because

A drop in EDV would decrease stroke volume, requiring a greater heart rate to restore cardiac output.

How do beta-1 adrenergic receptors increase cardiac output? .

By increasing the rate of depolarization of pacemaker cells in the SA node and increasing calcium release in cardiomyocytes

When scared, pressure generated by the left ventricle would

Increase

When does the left ventricle contain the least blood?  (If two answers are equal, choose both).

C and D

At the peak of systole, pressure is highest in the

Left ventricle

This question refers to the pathway of a red blood cell through the circulatory system. The structure encountered after passing through the pulmonary semilunar valve would be the

Pulmonary valve

How do beta-1 adrenergic receptors increase cardiac output? 

By increasing HR and decreasing ESV

Blood question: Lipids traveling in our bloodstream are

Carried by plasma proteins

In what order should the following cells spontaneously depolarize to threshold? 

Cells in the SA node, Cells in the AV node, Cells in the Bundle of His, Cardiomyocyte in the left ventricle

Many choice: Valves in the heart are located

Between major arteries and ventricles, between the atria and ventricles

What are the units for the Y-axis in chart 2?  

mm Hg

If all heart valves were removed from the heart, but ventricular pressure did not change during systole, which of the following would occur during ventricular contraction

Blood would flow both directions