Chapter 42.3

Question 1

A vessel’s cavity

Answer 1

the central lumen

Question 2

central lumen

Answer 2

a vessel’s cavity

Question 3

The epithelial layer that lines blood vessels

Answer 3

endothelium

Question 4

endothelium

Answer 4

the epithelial later that lines blood vessels

Question 5

The endothelium is…

Answer 5

smooth and minimizes resistance

Question 6

Capillaries

Answer 6

1. are only slightly wider than a red blood cell

2. have thin walls, the endothelium plus its basal lamina

Question 7

why do capillaries have the endothelium and its basal lamina

Answer 7

to facilitate the exchange of materials

Question 8

What do arteries and veins have?

Answer 8

endothelium, smooth muscle, and connective tissue

Question 9

How do arteries differ from veins?

Answer 9

they have thicker walls to accommodate the high pressure of blood pumped from the heart

Question 10

how do veins differ from arteries?

Answer 10

they have thinner-walls, blood flows back to the heart mainly as a result of muscle action

Question 11

What affects blood flow and blood pressure?

Answer 11

physical laws governing movement of fluids through pipes

Question 12

Where is the velocity of blood flow the slowest

Answer 12

capillary beds

Question 13

why is the velocity of blood flow the slowest in capillary beds

Answer 13

the high resistance and large total cross-sectional area

Question 14

Why is blood flow in the capillaries necessarily slow?

Answer 14

for exchange of materials

Question 15

Where does blood flow?

Answer 15

from areas of high pressure to areas of lower pressure

Question 16

What is blood pressure

Answer 16

the pressure that blood exerts in all directions, including against the walls of blood vessels

Question 17

What does the recoil of elastic arterial walls play a role in

Answer 17

maintaining blood pressure

Question 18

What dissipates much of the pressure

Answer 18

the resistance to blood flow in the narrow diameters of tiny capillaries and arterioles

Question 19

Systolic pressure

Answer 19

the pressure in the arteries during ventricular systole

Question 20

the pressure in the arteries during ventricular systole

Answer 20

systolic pressure

Question 21

what is the highest pressure in the arteries called

Answer 21

systolic pressure

Question 22

diastolic pressure

Answer 22

the pressure in the arteries during diastole

Question 23

the pressure in the arteries during diastole

Answer 23

diastolic pressure

Question 24

is lower than systolic pressure

Answer 24

diastolic pressure

Question 25

a pulse

Answer 25

is the rhythmic bulging of artery walls with each heartbeat

Question 26

the rhythmic bulging of artery walls with each heartbeat

Answer 26

a pulse

Question 27

How do homeostatic mechanisms regulate arterial blood pressure

Answer 27

by altering the diameter of arterioles

Question 28

vasoconstriction

Answer 28

the contraction of smooth muscle in arteriole walls

Question 29

the contraction of smooth muscle in arteriole walls

Answer 29

vasoconstriction

Question 30

increases blood pressure

Answer 30

vasoconstriction

Question 31

vasodilation

Answer 31

the relaxation of smooth muscles in the arterioles

Question 32

the relaxation of smooth muscles in the arterioles

Answer 32

vasodilation

Question 33

causes blood pressure to fall

Answer 33

vasodilation

Question 34

a major inducer of vasodilation

Answer 34

nitric oxide

Question 35

a strong inducer of vasoconstriction

Answer 35

the peptide endothelin

Question 36

What are vasoconstriction and vasodilation often coupled to

Answer 36

changes in cardiac output that affect blood pressure

Question 37

What is blood pressure generally measured for

Answer 37

an artery in the arm at the same height as the heart

Question 38

What has a significant effect on blood pressure

Answer 38

gravity

Question 39

What is fainting caused by

Answer 39

inadequate blood flow to the head

Question 40

what do animals with long necks require

Answer 40

a very high systolic pressure to pump blood a great distance against gravity

Question 41

What is blood moved through the veins by

Answer 41

smooth muscle contraction, skeletal muscle contraction, and expansion of the vena cava with inhalation

Question 42

what do one-way valves in veins prevent

Answer 42

backflow of blood

Question 43

What percent of the body's capillaries does blood flow through at any given time

Answer 43

5-10%

Question 44

how filled are capillaries in major organs usually

Answer 44

to capacity

Question 45

What two mechanisms regulate distribution of blood in capillary beds

Answer 45

1. constriction/dilation of arterioles that supply capillary beds 2. precapillary sphincters

Question 46

precapillary sphincters

Answer 46

control the flow of blood between arterioles and venules

Question 47

what is blood flow regulated by

Answer 47

nerve impulses, hormones, and other chemicals

Question 48

Where does the exchange of substances between the blood and interstitial fluid take place

Answer 48

across the thin endothelial walls of the capillaries

Question 49

What does the difference between blood pressure and osmotic pressure drive

Answer 49

fluids out of capillaries at the arteriole end and into capillaries at the venule end

Question 50

Why can most blood cells and blood proteines not pass through the endothelium

Answer 50

they are too large

Question 51

Lymphatic system

Answer 51

returns fluids that leaks out from the capillary beds

Question 52

returns fluids that leaks out from the capillary beds

Answer 52

lymphatic system

Question 53

fluid lost by capillaries

Answer 53

lymph

Question 54

lymph

Answer 54

fluid lost by capillaries

Question 55

What does the lymphatic system drain into

Answer 55

veins in the neck

Question 56

What do valves in lymph vessels do

Answer 56

prevent the backflow of fluid

Question 57

edema

Answer 57

swelling caused by disruptions in the flow of lymph

Question 58

swelling caused by disruptions in the flow of lymph

Answer 58

edema

Question 59

lymph nodes

Answer 59

organs that filter lymph and play an important role in the body's defense

Question 60

organs that filter lymph and play an important role in the body's defense

Answer 60

lymph nodes

Question 61

What occurs when the body is fighting an infection

Answer 61

lymph nodes become swollen and tender