Chapter 21

Question 1

Arteries

Answer 1

Carry blood away from the heart to other organs

Question 2

Arterioles

Answer 2

Artery that delivers blood to a capillary

Question 3

Capillary

Answer 3

A microscopic blood vessel located between an arteriole and venule through which materials are exchange between blood and interstitial fluid

Question 4

Venules

Answer 4

a small vein that collects blood from capillaries and delivers it to a vein

Question 5

Vein

Answer 5

blood vessel that conveys blood from tissues back to the heart

Question 6

Tunica interna

Answer 6

the deep coat of an artery or vein, consisting of a lining of endothelium, basement membrane, and internal elastic lamina; forms the inner lining of a blood vessel and is in direct contact with the blood as it flows through the lumen; the interior opening of the vessel

Question 7

Lumen

Answer 7

Space within an artery or vein

Question 8

Endothelium

Answer 8

the innermost layer; continuous with the endocardium lining of the heart

Question 9

Basement membrane

Answer 9

thin, extracellular layer between epithelium and connective tissue consisting of a basal lamina and a reticular lamina; provides a physical support base for the epithelial layer

Question 10

Internal elastic lamina

Answer 10

the outermost part of the tunica media, which forms the boundary between the tunica interna and tunica media; thin sheet of elastic fibres with openings that facilitate diffusion of materials through the tunica interna to the thicker tunica media

Question 11

Tunica media

Answer 11

a muscular and connective tissue layer that displays the greatest variation among the different vessel types; the intermediate coat of an artery or vein, composed of smooth muscle and elastic fibres

Question 12

Vasoconstriction

Answer 12

a decrease in the size of the lumen of a blood vessel caused by contraction of the smooth muscle in the wall of the vesicle; an increase in sympathetic stimulation typically stimulates the smooth muscle to contract, squeezing the vessel wall and narrowing the lumen

Question 13

Vasodilation

Answer 13

when sympathetic stimulation decreases, or in the presence of certain chemicals or in response to blood pressure, smooth muscle fibres relax; the increase in lumen diameter

Question 14

External elastic lamina

Answer 14

part of the tunica media; network of elastic fibres that separate the tunica media from the tunica externa

Question 15

Tunica externa

Answer 15

the outer covering of a blood vessel; consists of elastic and collagen fibres and numerous nerves; contains tiny blood vessels that supply the tissue of the vessel wall

Question 16

Vasa vasorum

Answer 16

the small blood vessels of the tunica externa that supply blood to the tissues of the vessel

Question 17

Elastic arteries

Answer 17

the largest arteries in the body; they have the largest diameter among arteries, but their vessel walls are relatively thin compared with the overall size of the vessel

Question 18

Elastic lamellae

Answer 18

characteristic internal and external elastic laminae of elastic arteries; along a thick tunica media that is dominated by elastic fibres; help propel blood onward while the ventricles are relaxing

Question 19

Pressure reservoir

Answer 19

as blood is ejected from the heart in to elastic arteries, their walls stretch, easily accommodating the surge of blood. As they stretch, the elastic fibres momentarily store mechanical energy