Unit 4 -Vasculature: Microcirculation, lymphatics, and Veins

Question 1

What are the four types of capillaries?

Answer 1

Continuous capillaries, fenestrated capillaries, sinusoids (discontinuous capillaries), and lymphatic capillaries

Question 2

What are is the most common type of capillaries?

Answer 2

continuous capillaries

Question 3

What is the structure of continuous capillaries?

Answer 3

made up of tight junctions with no pinocytotic vesicles or clefts

Question 4

What is the function of continuous capillaries?

Answer 4

they carry proteins for amino acids and glucose

Question 5

Where are fenestrated capillaries located?

Answer 5

in the GI tract/intestine, kidney, and endocrine pancreas

Question 6

Where are the fenestrations of fenestrated capillaries located?

Answer 6

in the capillary wall

Question 7

What is the function of fenestrated capillaries?

Answer 7

they allow rapid exchange of large molecules and fluid

Question 8

What is the structure of sinusoids?

Answer 8

they have large clefts and fenestrae and a discontinuous basal lamina layer

Question 9

Where are sinusoid capillaries located?

Answer 9

in the liver, spleen, lymphoid organs and bone marrow

Question 10

What is the function of sinusoid capillaries?

Answer 10

they allow rapid exchange of larger molecules, particles, whole cells, and fluid between the blood and interstitium

Question 11

What is the structure of lymphatic capillaries?

Answer 11

the endothelium overlaps in places, there are no tight junctions, it has intercellular clefts

Question 12

What are lymphatic capillaries supported by?

Answer 12

anchoring filaments

Question 13

What is the function of lymphatic capillaries?

Answer 13

they pull away fluid to keep the interstitium dry so that filtration can continuously occur

Question 14

What does bulk flow occur through?

Answer 14

capillary pores

Question 15

What influences bulk flow?

Answer 15

hydrostatic pressure

Question 16

What does fluid movement across the capillary membrane depend on?

Answer 16

the sum of osmotic pressure and hydrostatic pressure across the membrane

Question 17

Where is fluid filtered and where is it absorbed?

Answer 17

it is filtered at the arteriole end and absorbed at the venous end

Question 18

What is the Starling equation?

Answer 18

Kf(Pc-Pi)-(πc - πi)

Question 19

What does Pc in the starling equation stand for?

Answer 19

capillary hydrostatic pressure

Question 20

What does Pi in the starling equation stand for?

Answer 20

interstitial hydrostatic pressure

Question 21

What does πc in the starling equation stand for?

Answer 21

capillary oncotic pressure

Question 22

What does πi in the starling equation stand for?

Answer 22

interstitial oncotic pressure

Question 23

What does causes interstitial edema?

Answer 23

increase in capillary hydrostatic pressure
decrease in capillary oncotic pressure
increase in capillary permeability
decrease in lymphatic flow

Question 24

What is the function of lymphatics?

Answer 24

drain excess fluid from interstitial space, removing excess interstitial protein and returning it back into circulation, and removing particles and bacteria into the blood system

Question 25

What determines the rate of lymph flow?

Answer 25

muscle contraction, movement, and arterial pulsations

Question 26

What influences pressure in all systemic veins?

Answer 26

right arterial pressure

Question 27

What does greater venous restriction influence?

Answer 27

flow

Question 28

What is the function of veins?

Answer 28

return blood to the heart and are storage areas

Question 29

What is vascular compliance?

Answer 29

The ability of a blood vessel wall to expand and contract passively with changes in pressure is an important function of large arteries and veins.

Question 30

How is vascular compliance calculated?

Answer 30

ΔV/ΔP

Question 31

When the heart starts, what happens to the volume in veins?

Answer 31

it decreases

Question 32

How does a rapid increase in volume affect veins?

Answer 32

It increases its pressure but not drastically

Question 33

When the heart starts, what happens to volume in arteries?

Answer 33

it increases

Question 34

How does a rapid increase in volume affect the pressure in arteries?

Answer 34

It increases it dramatically