content review 4

In the image above, at which point would you expect to find the semilunar valves closed?

A, C

In the image above, at which point would you expect to find the semilunar valves open?

B

In the image above, at which point would you expect to find the atria and ventricles relaxed?

C

The plateau of the action potential in cardiac ventricular cells results from the opening of voltage-gated long-lasting __________ channels in the plasma membrane of the cell.

Ca 2+

What is the primary difference between repolarization in skeletal muscle cells and cardiac muscle cells?

Cardiomyocytes must pump calcium into the interstitial fluid during repolarization.

Which of the following statements about the cardiac cycle is TRUE?

Closure of the atrioventricular valves occurs at the beginning of ventricular systole.

Which of the following ECG waves is due to depolarization across the internodal pathways?

P wave

During which of the following ECG waves would you expect the ventricles to be in diastole.

P wave T wave

During which of the following ECG waves would you expect the greatest increase of blood pressure

QRS complex

During which of the following ECG waves would you expect the ventricles to be in systole.

QRS complex

During which of the following ECG waves would you expect the atria to be in diastole.

QRS complex T wave

Which best defines cardiac output?

The product of the heart rate and the volume ejected from the ventricle during a cardiac cycle

Which is correct about the contraction sequence of the heart?

The two atria contract at the same time, and as they are relaxing, the two ventricles contract together.

Action potentials in the heart spread from cell to cell through __________.

gap junctions

The earliest organ to form and begin function within the developing human is the ________.

heart

In a healthy young adult, what happens to cardiac output when heart rate increases above 160 bpm?

it decreases

Which of the following is the best classification of nodal cells?

myocardial conducting cells

When thinking about mechanical actions of the heart, after which event would expect to find the least end systolic volume?

ventricular contractions

Ventricular relaxation immediately follows ________.

ventricular repolarization