Cardiovascular system:Functions of the Circulatory System

Question 1

carry blood away from the heart.

Answer 1

arteries

Question 2

Blood flows from arterioles into_____
the most common blood vessel

Answer 2

capillaries

Question 3

From the capillaries, blood flows into______

Answer 3

veins

Question 4

All blood vessels have an internal lining of simple squamous epithelial cells called______ which is continuous with the endocardium of the heart.

Answer 4

endothelium

Question 5

Scattered along the length of the capillary are __________ closely associated with the endothelial cells.

Answer 5

pericapillary cells

Question 6

approximately 7-9 um in diameter, and their walls exhibit no gaps between the endothelial cells

Answer 6

Continuous capillaries

Question 7

endothelial cells have numerous fenestrae

Answer 7

fenestrated capillaries

Question 8

larger in diameter than either continuous or fenestrated capillaries, and their basement membrane is less prominent or completely absent.

Answer 8

fenestrated capillaries,

Question 9

are areas approximately 70-100 nm in diameter in which the cytoplasm is absent and the plasma membrane consists of a porous diaphragm that is thinner than the normal plasma membrane.

Answer 9

fenestrae

Question 10

are larger in diameter than either continuous or fenestrated capillaries, and their basement membrane is less prominent or completely absent.

Answer 10

Sinusoidal capillaries

Question 11

are large-diameter sinusoidal capillaries.

Answer 11

Sinusoids

Question 12

are similar in structure to the sinusoidal capillaries but even larger in diameter.

Answer 12

Venous sinuses

Question 13

Blood flows from arterioles through_______ vessels with isolated smooth muscle cells along their walls.

Answer 13

metarterioles

Question 14

Blood then flows from a metarteriole into a__________________, a vessel that extends in a relatively direct fashion from a metarteriole to a venule.

Answer 14

thoroughfare channel

Question 15

smooth muscle cells located at the origin of the branches. Blood then flows through the capillary network into the venules.

Answer 15

precapillary sphincters

Question 16

The ends of capillaries closest to the arterioles are

Answer 16

arterial capillaries

Question 17

the ends closest to venules are

Answer 17

venous capillaries

Question 18

allow blood to flow from arterioles to small veins without passing through capillaries.

Answer 18

Arteriovenous Anastomoses

Question 19

is an arteriovenous anastomosis that consists of arterioles with abundant smooth muscle in their walls.

Answer 19

glomus

Question 20

can result from injury or tumors.

Answer 20

Pathologic arterio-venous anastomoses

Question 21

(TRUE OR FALSE)
blood vessel walls consist of three relatively distinct layers, which are most evident in the muscular arteries and least evident in the veins.

Answer 21

true

Question 22

From the lumen to the outer wall of the blood vessels, the layers, or_____

Answer 22

tunics

Question 23

3 relatively distinct layers of blood vessels

Answer 23

(1) the tunica intima, (2) the tunica media, and (3) the tunica adventitia, or tunica externa

Question 24

consists of endothelium, a delicate connective tissue basement membrane,

Answer 24

tunica intima

Question 25

fenestrated layer of elastic fibers called

Answer 25

internal elastic membrane.

Question 26

consists of smooth muscle cells arranged circularly around the blood vessel.

Answer 26

tunica media, or middle layer

Question 27

decrease in blood vessel diameter caused by smooth muscle contraction.

Answer 27

vasoconstriction

Question 28

An increase in blood flow is produced by_____

Answer 28

vasodilation

Question 29

which separates the tunica media from the tunica adventitia, can be identified at the outer border of the tunica media in some arteries.

Answer 29

external elastic membrane

Question 30

composed of connective tissue, which varies from dense connective tissue near the tunica media to loose connective tissue that merges with the connective tissue surrounding the blood vessels.

Answer 30

tunica adventitia

Question 31

have the largest diameters and are often called conducting arteries.

Answer 31

Elastic Arteries

Question 32

include medium-sized and small arteries.

Answer 32

Muscular Arteries

Question 33

transport blood from small arteries to capillaries and are the smallest arteries in which the three tunics can be identified

Answer 33

Arterioles

Question 34

with a diameter of up to 50 um, are tubes composed of endothelium resting on a delicate basement membrane.

Answer 34

venules

Question 35

also have a tunica adventitia composed of collagenous connective tissue.

Answer 35

small veins

Question 36

Most of the veins observed in gross anatomical dissections, except for the large veins,

They collect blood from small veins and deliver it to large veins.

Answer 36

medium veins

Question 37

transport blood from the medium veins to the heart.

Answer 37

large veins

Question 38

begin in a primary capillary network, extend some distance, and end in a secondary capillary network.

Answer 38

portal veins

Question 39

Veins that have diameters greater than 2 mm contain______, which allow blood to flow toward the heart, but not in the opposite direction

Answer 39

valves

Question 40

nutrients are supplied to their walls by way of small blood vessels called

which penetrate from the exterior of the vessel to form a capillary network in the tunica adventitia and the tunica media

Answer 40

vasa vasorum

Question 41

consists of degenerative changes in arteries that make them less elastic.

Answer 41

Arteriosclerosis

Question 42

is the deposition of material in the walls of arteries to form distinct plaques.

Answer 42

Atherosclerosis