Ch 21 blood vessels

Question 1

Compared to arteries, veins

Answer 1

have thinner walls.

Question 2

The smallest arterial branches are called the

Answer 2

arterioles

Question 3

The layer between the tunica media and the tunica externa in a large artery is the

Answer 3

external elastic membrane.

Question 4

In arteries, the thick layer of elastic fibers associated with the tunica intima is called the

Answer 4

internal elastic membrane

Question 5

Venoconstriction ________ the amount of blood within the venous system, which ________ the volume in the arterial and capillary systems.

Answer 5

reduces; increases

Question 6

Which of the following vessels changes diameter most readily to local conditions or SNS stimulation?

Answer 6

arterioles

Question 7

Blood flow through a capillary is controlled by the

Answer 7

precapillary sphincter.

Question 8

What vessels contain elastic fibers in the walls that are stretched during systole?

Answer 8

arteries

Question 9

Blood moves forward through veins because of all of the following

Answer 9

• muscular compression.
• the respiratory pump.
• the pressure in the veins is lower than in the arteries.
• valves in the veins preventing the backward flow of blood.

Question 10

Blood moves forward through veins because of all of the following except

Answer 10

pumping by the smooth muscle in the wall of the vein.

Question 11

Which part of the vascular system functions as a blood reservoir and contains over 60% of the body’s blood?

Answer 11

veins

Question 12

The ________ are small blood vessels that nourish tissue components in the wall of large arteries and veins.

Answer 12

vasa vasorum

Question 13

The tunica intima consists of

Answer 13

simple squamous epithelium and loose connective tissue

Question 14

What are the layers of blood vessels from outside to inside?

Answer 14

tunica externa; tunica media; tunica interna

Question 15

What is the difference between elastic arteries and muscular arteries?

Answer 15

Elastic arteries have elastic fibers throughout the tunica media whereas muscular arteries have few elastic fibers in the tunica media.

Question 16

Which vessel has only the tunica intima layer?

Answer 16

capillary

Question 17

In the bone marrow, new blood cells must enter the circulation through

Answer 17

sinusoidal capillaries

Question 18

What structural component gives arteries the ability to passively adapt to changes in blood pressures that accompany the heartbeat?

Answer 18

elastic fibers

Question 19

Which of the following can be stated based on at least one of the graphs shown here?

Answer 19

Which of the following can be stated based on at least one of the graphs shown here?

Question 20

Which of the following would increase vascular resistance? increased vessel length, increased vessel luminal diameter, turbulence. (Figure 21-7)

Answer 20

increased vessel length and turbulence

Question 21

Resistance is a force that

Answer 21

decreases blood flow.

Question 22

Blood flow to a tissue will increase if the

Answer 22

arterioles dilate.

Question 23

Blood pressure increases with all of the following except increased

Answer 23

parasympathetic innervation.

Question 24

Which of the following factors will increase the net filtration pressure to move fluid out of capillaries?

Answer 24

both decreased plasma albumin and increased blood hydrostatic pressure

Question 25

If blood pressure doubled, the blood flow through a vessel would be

Answer 25

doubled

Question 26

In which of the following would the blood flow be highest?

Answer 26

a vessel 1.0 cm in diameter and 2 meters long

Question 27

The blood colloid osmotic pressure mostly depends on the

Answer 27

concentration of plasma proteins

Question 28

Each of the following changes will result in increased blood flow to a tissue except

Answer 28

increased hematocrit

Question 29

In comparison to a vessel with a large diameter, a vessel with a small diameter has

Answer 29

a greater resistance to blood flow.

Question 30

As blood circulates from arteries into capillaries, the total cross-sectional area of capillaries

Answer 30

increases and causes the blood velocity to decrease.

Question 31

The force that moves fluid out of capillaries is ________ pressure whereas the opposing force that moves fluid into capillaries is ________ pressure.

Answer 31

hydrostatic; colloid osmotic

Question 32

Some of the fluid that is forced out of capillaries is returned to the blood by the

Answer 32

lymphatic system

Question 33

Edema may occur when

Answer 33

- Edema may occur when the plasma concentration of protein is reduced, - capillary hydrostatic pressure is elevated, - the capillary endothelium permeability goes up

Question 34

You can expect children to have lower blood pressures than adults on average because

Answer 34

their blood vessel length is less.

Question 35

Total systemic cross-sectional area is highest in

Answer 35

capillaries

Question 36

Which of the following is true of arteries compared to other vessels?

Answer 36

Blood pressure and velocity are highest.

Question 37

Which of the following is true of capillaries compared to other vessels?

Answer 37

Cross-sectional area is highest and velocity is lowest.

Question 38

When the net filtration pressure is negative, what process is occurring?

Answer 38

Fluid is moving back into the capillary.

Question 39

Identify how the heart will respond given the imbalance shown in the image.

Answer 39

Cardiac output will increase.

Question 40

Stimulation of the aortic baroreceptors reflexively results in

Answer 40

increased activity by the parasympathetic nervous system.

Question 41

Increased levels of carbon dioxide in the blood will result in decreased

Answer 41

parasympathetic stimulation of the heart

Question 42

Which of the following changes does not occur during exercise compared to rest?

Answer 42

Skin blood flow is lower.

Question 43

When muscle cells contract, they release substances that cause nearby precapillary sphincters to relax. This is an example of __________.

Answer 43

utoregulation

Question 44

Which of the following is true of both lymphatic capillaries and blood capillaries?

Answer 44

Both types are composed of endothelium.

Question 45

Lymphatic vessels provide a conduit for metastasizing cancer cells. Ideally, such cells are removed and destroyed by what structure, which thus prevents the spread of cancer?

Answer 45

lymph nodes

Question 46

What feature do lymphatic vessels share with veins that allows lymph to flow in only one direction? (Figure 22-3)

Answer 46

valves

Question 47

What types of cells are found in the white pulp of the spleen and in the red pulp of the spleen? (Figure 22-8)

Answer 47

lymphocytes; red blood cells

Question 48

The lymphatic system does all of the following

Answer 48

- transports lipids from the digestive tract. - eliminates variations in the composition of interstitial fluid. - helps maintain normal blood volume. - fights infection.

Question 49

The lymphatic system does all of the following except

Answer 49

transports gases to and away from lymph nodes.

Question 50

Compared to blood capillaries, lymph capillaries exhibit all of the following except that they

Answer 50

are smaller in diameter.

Question 51

Lymph nodes do all of the following except

Answer 51

remove excess nutrients from the lymph.

Question 52

________ are large lymphatic nodules that are located in the walls of the pharynx

Answer 52

Tonsils

Question 53

Lymphatic organs differ from lymphatic tissues in what way?

Answer 53

They are surrounded by a fibrous capsule and lymphatic tissues are not.

Question 54

Lymphatic capillaries are known for all of the following except

Answer 54

allowing nutrient and gas exchange.

Question 55

Stem cells that can form all types of lymphocytes are concentrated in the

Answer 55

red bone marrow

Question 56

If the thymus shrank and stopped making thymosins, we would expect to see an immediate decrease in the number of

Answer 56

T cells

Question 57

The primary lymphoid tissues include

Answer 57

the bone marrow and thymus

Question 58

Large lymphatic vessels have a wall structure most similar to which blood vessel?

Answer 58

veins

Question 59

The lymphoid organ that acts like a filter as lymph passes through is

Answer 59

lymph nodes