Tissue Perfusion

Question 1

what is the purpose of thin capillary walls?

Answer 1

delivery of O2 and nutrients to and removal of wastes from tissue cells

gas exchange in the lungs

absorption of nutrients in the digestive tract

urine formation in the kidneys

Question 2

what is extrinsic control of blood flow?

Answer 2

SNS and hormones control through the whole body

Question 3

what is intrinsic control of blood flow?

Answer 3

local control of blood flow to meet specific tissue needs

Question 4

intrinsic redistribution of blood during exercise

Answer 4

skeletal muscle arterioles dilate, increasing blood flow to muscle

Question 5

extrinsic redistribution of blood during exercise

Answer 5

decrease blood flow to other organs

Question 6

low pH or high Co2 leads to vasodilation or vasoconstriction?

Answer 6

vasodilation

Question 7

decreased MAP will lead to dilated or constricted cerebral vessels?

Answer 7

dilated

Question 8

increased MAP will lead to dilated or constricted cerebral vessels?

Answer 8

constricted

Question 9

will increased temp increase or reduce vasoconstriction?

Answer 9

reduce

Question 10

what are the 4 routes of capillary exchange?

Answer 10

diffuse directly through endothelial membranes (lipid soluble)

pass through clefts (water soluble)

pass through fenestrations

active transport via vesicles

Question 11

what does decreased temp lead to?

Answer 11

blood shunted to vital organs

Question 12

what are hydrostatic pressures?

Answer 12

force exerted by fluid against wall

Question 13

what is capillary hydrostatic pressure?

Answer 13

capillary BP that tends to force fluids through capillary walls

greater at arterial end (35) than venule end (17)

Question 14

what is interstitial fluid hydrostatic pressure?

Answer 14

pressure pushing fluid back into vessel

pressing on outside of capillary walls

typically very low bc not all fluid goes back into venous system

Question 15

what is capillary colloid osmotic pressure?

Answer 15

“sucking”

pulling water back into capillary

about 26 mmHg

Question 16

what is interstitial fluid colloid osmotic pressure?

Answer 16

inconsequential bc of low protein content

about 1 mmHg

high protein = hypovolemia

Question 17

what is net friction pressure?

Answer 17

all forces acting on capillary bed

(HPc+OPif) - (HPif+OPc)

Question 18

net flow at arterial end

Answer 18

filtration

Question 19

net flow at venous end

Answer 19

reabsorption

Question 20

does more leave at arterial or venous end?

Answer 20

arterial end

Question 21

order of flow

Answer 21

aorta–> arteries–> arterioles–> capillaries–> interstitial space–> most back to venous system

Question 22

what is edema? what factors surrounding tissue perfusion can cause this?

Answer 22

abnormal increase in interstitial fluid

increased outward pressure or decreased inward pressure

increased HPc=increased fluid loss

increased OPif=fluid into interstitial space

decreased OPc= decreased return to blood

decreased drainage of interstitial fluid

Question 23

pulmonary circulation

Answer 23

heart to lungs and back to heart

Question 24

systemic circulation

Answer 24

all parts of body back to heart

Question 25

what is the Bohr effect?

Answer 25

O2 dissociating from hemoglobin

right shift