Review Questions

1. Which of the following is not important in preventing backflow of blood?

a chordae tendineae

b papillary muscles

c AV valves

d endocardium

 

2. Which valve separates the left atrium from the left ventricle?

a mitral

b tricuspid

c pulmonary

d aortic

 

3. Which of the following lists the valves in the order through which the blood flows from the vena cava through the heart?

a tricuspid, pulmonary semilunar, bicuspid, aortic semilunar

b mitral, pulmonary semilunar, bicuspid, aortic semilunar

c aortic semilunar, pulmonary semilunar, tricuspid, bicuspid

d bicuspid, aortic semilunar, tricuspid, pulmonary semilunar

 

4. Which chamber initially receives blood from the systemic circuit?

a left atrium

b left ventricle

c right atrium

d right ventricle

 

5. The ________ layer secretes chemicals that help to regulate ionic environments and strength of contraction and serve as powerful vasoconstrictors.

a pericardial sac

b endocardium

c myocardium

d epicardium

 

6. The myocardium would be the thickest in the ________.

a left atrium

b left ventricle

c right atrium

d right ventricle

 

7. In which septum is it normal to find openings in the adult?

a interatrial septum

b interventricular septum

c atrioventricular septum

d all of the above

 

8. Which of the following is unique to cardiac muscle cells?

a Only cardiac muscle contains a sarcoplasmic reticulum.

b Only cardiac muscle has gap junctions.

c Only cardiac muscle is capable of autorhythmicity

d Only cardiac muscle has a high concentration of mitochondria.

 

9. The influx of which ion accounts for the plateau phase?

a sodium

b potassium

c chloride

d calcium

 

10. Which portion of the ECG corresponds to repolarization of the atria?

a P wave

b QRS complex

c T wave

d none of the above: atrial repolarization is masked by ventricular depolarization

 

11. Which component of the heart conduction system would have the slowest rate of firing?

a atrioventricular node

b atrioventricular bundle

c bundle branches

d Purkinje fibers

 

12. The cardiac cycle consists of a distinct relaxation and contraction phase. Which term is typically used to refer ventricular contraction while no blood is being ejected?

a systole

b diastole

c quiescent

d isovolumic contraction

 

13. Most blood enters the ventricle during ________.

a atrial systole

b atrial diastole

c ventricular systole

d isovolumic contraction

 

14. The first heart sound represents which portion of the cardiac cycle?

a atrial systole

b ventricular systole

c closing of the atrioventricular valves

d closing of the semilunar valves

 

15. Ventricular relaxation immediately follows ________.

a atrial depolarization

b ventricular repolarization

c ventricular depolarization

d atrial repolarization

 

16. The force the heart must overcome to pump blood is known as ________.

a preload

b afterload

c cardiac output

d stroke volume

 

17. The cardiovascular centers are located in which area of the brain?

a medulla oblongata

b pons

c mesencephalon (midbrain)

d cerebrum

 

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

a It increases.

b It decreases.

c It remains constant.

d There is no way to predict.

 

19. What happens to preload when there is venous constriction in the veins?

a It increases.

b It decreases.

c It remains constant.

d There is no way to predict.

 

20. Which of the following is a positive inotrope?

a Na⁺

b K⁺

c Ca²⁺

d both Na⁺ and K⁺