Question

multiple choice
read each item carefully and then select the one best response.

1. ________ allows a cardiac muscle cell to contract spontaneously without a stimulus from a nerve source.

a. repetition
b. reactivity
c. automaticity
d. autonomy

1. the aorta receives its blood supply from the:

a. right atrium
b. left atrium
c. right ventricle
d. left ventricle

1. blood enters the right atrium from the body through the:

a. vena cava
b. aorta
c. pulmonary artery
d. pulmonary vein

1. the only vein(s) in the body that carry oxygenated blood is/are the:

a. external jugular veins
b. pulmonary veins
c. subclavian veins
d. inferior vena cava

1. normal electrical impulses originate in the sinus node, in the upper part of the right:

a. atrium
b. ventricle
c. superior vena cava
d. aortic arch

1. dilation of the coronary arteries ________ blood flow.

a. shuts off
b. increases
c. decreases
d. regulates

1. the ________ are tiny blood vessels that are approximately one cell thick.

a. arterioles
b. venules
c. capillaries
d. ventricles

1. ________ carry oxygen to the bodys tissues and then remove carbon dioxide.

a. red blood cells
b. white blood cells
c. platelets
d. veins

1. ________ is the maximum pressure exerted by the left ventricle as it contracts.

a. cardiac output
b. diastolic blood pressure
c. systolic blood pressure
d. stroke volume

Explanation:

1. Automaticity is the property of cardiac - muscle cells to contract spontaneously without nerve stimulation.
2. The aorta receives blood from the left ventricle during ventricular systole.
3. Deoxygenated blood from the body enters the right atrium through the vena cava.
4. Pulmonary veins carry oxygenated blood from the lungs to the left atrium.
5. The sinus node, the heart's natural pacemaker, is located in the upper part of the right atrium.
6. Dilation of coronary arteries increases blood flow to the heart muscle.
7. Capillaries are tiny, one - cell - thick blood vessels for gas and nutrient exchange.
8. Red blood cells transport oxygen to tissues and remove carbon dioxide.
9. Systolic blood pressure is the maximum pressure exerted by the left ventricle during contraction.

Answer:

1. C. Automaticity
2. D. left ventricle
3. A. vena cava
4. B. pulmonary veins
5. A. atrium
6. B. increases
7. C. capillaries
8. A. Red blood cells
9. C. Systolic blood pressure