19. The Blood Vessels

Which of the following statements is true?

Which blood vessel layer contains the greatest proportion of collagen?

Which blood vessel tunic has the most active role in controlling blood flow?

Describe neural and chemical (both systemic and local) effects exerted on the blood vessels when you are fleeing from a mugger. (Be careful, this is more involved than it appears at first glance.)

The structure of a capillary wall differs from that of a vein or an artery because

a. it has two tunics instead of three

b. there is less smooth muscle

c. it has a single tunic—only the tunica intima

d. none of these

More than one choice may apply.

Which layer of the artery wall thickens most in atherosclerosis?

a. Tunica media

b. Tunica intima

c. Tunica adventitia

d. Tunica externa

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

The tunica intima is composed of a sheet of endothelium, connective tissue, and the internal elastic lamina.

Collagen vascular diseases weaken the collagen in the tunica externa of blood vessels. Predict the effects of such a disease.

Baroreceptors that function in the regulation of blood pressure are located in the:

(a) Left ventricle

(b) Brainstem

(c) Carotid sinus

(d) Common iliac artery

(e) Pulmonary trunk