Chapter 12

The semilunar valves prevent the backflow of blood from the a. arteries to the ventricles. b. veins to the atria. c. ventricles to the atria. d. arteries to the atria.

If you cut all the nerves to the heart but kept the heart alive, a. the heart would stop beating. b. the heart would continue beating. c. only systole would occur. d. only diastole would occur.

Imagine that you have been miniaturized and are riding through the circulatory system using a red blood cell as a life raft. You are in the big toe traveling toward the heart. The last vessel you pass through before entering the heart is the a. aorta. b. inferior vena cava. c. coronary artery. d. pulmonary vein.

Imagine that you have been miniaturized and are riding through the circulatory system using a red blood cell as a life raft. You are nearly deafened by the first heart sound, which is caused by a. the opening of the atrioventricular valves. b. the closing of the atrioventricular valves. c. the opening of the semilunar valves. d. the closing of the semilunar valves.

Imagine that you have been miniaturized and are riding through the circulatory system using a red blood cell as a life raft. You are wearing sensitive equipment that may be damaged by high pressure. The blood pressure would be highest when you are in the aorta during a. atrial systole. b. ventricular systole. c. atrial diastole. d. ventricular diastole.

Heart tissue is nourished by a. the SA node. b. the blood passing through the chambers of the heart. c. the chordae tendineae. d. blood in the coronary blood vessels (i.e., through the coronary arteries to capillaries).

The second heart sound (dup) is the sound of the a. pacemaker initiating its contraction. b. blood entering the aorta. c. closing of the semilunar valves. d. closing of the atrioventricular (AV) valves.

The chordae tendineae a. keep the semilunar valves open. b. keep the AV valves from being pushed into the atria during ventricular systole. c. stimulate the SA node. d. are part of the internal conduction system of the heart.

Which blood vessels have the thickest, most elastic walls? a. arteries b. capillaries c. veins d. venules

Functions of the lymphatic system include a. transporting products of fat digestion from the small intestine to the bloodstream. b. defending against disease-causing organisms. c. returning excess interstitial fluid to the bloodstream. d. all of the above.

Lymph nodes a. are sacs filled with lymph. b. return excess interstitial fluid to the bloodstream. c. filter and cleanse lymph. d. are pumps that keep lymph flowing through lymphatic vessels.