Module 2.4 - Biolfuid Transport IV (Capillary Flow)

Question 1

Capillary “leakage”

Answer 1

Capillaries act as semi-permeable membranes through which fluid transfer and solutes travel

Question 2

Fenistrative capillaries

Answer 2

Have more openings in capillary membrane

Question 3

Inverse of resistance to flow measured across membrane

Answer 3

Filtration coeff (1/R = K_f)

Question 4

T/F: Overall area for convection is much greater in capillary than for diffusion

Answer 4

F: Much greater for diffusion than convection (very limited SA for convection to occur)

Question 5

2 pressures within capillaries that drive water flow

Answer 5

Hydrostatic pressure (left vent contraction)

Osmotic pressure

Question 6

How is osmotic pressure generated?

Answer 6

When semi-perm membrane has diff concentrations of same substance on diff sides

Question 7

Interstitial fluid

Answer 7

Fluid on outside of capillaries (in tissues)

Question 8

T/F: Diameter of capillary is only large enough to allow one cell to move through vessel at a time

Answer 8

T

Question 9

T/F: Any type of cell can move across different kinds of capillary membranes

Answer 9

F: cells move across the membrane if they have right diameter

Question 10

Van Hoff eqn

Answer 10

Osmotic pressure = cRT

c = concentration dissolved solute
R = gas cst
T = temp

Question 11

T/F: Van Hoff eqn applicable across ideal and non-ideal cases

Answer 11

F: Ideal or ideally dilute

Question 12

T/F: Starling equation was empirically derived

Answer 12

F: Semi-empirical

Question 13

T/F: Hydrostatic pressure inside capillary (P_c) is constant across any capillary

Answer 13

F: NOT constant, decreases as it travels through capillaries

Question 14

Hydrostatic pressure in capillaries is _______ below the heart, and ________ above the heart

Answer 14

Higher

Lower

Question 15

T/F: Interstitial pressure (P_s) is slightly negative

Answer 15

T

Question 16

T/F: Osmotic P inside capillary is driven principally by lipid content

Answer 16

F: Protein content

Question 17

On venule side of capillary, the osmotic process starts to ______ and fluid moves _______ the tissues

Answer 17

Reverse

Back into

Question 18

Lymphatic system

Answer 18

Another way (besides circulatory system) of removing interstitial fluid from tissues (low in protein content, high in salts, AAs, CO2 and waste)

Question 19

T/F: Lymph nodes shrink during infection

Answer 19

F: They swell - leukocytes (WBCs) accumulate in lymph nodes during infection

Question 20

T/F: Lymph system has one-way valves like veins, and lymph fluid gets moved back to the heart through muscle action

Answer 20

T

Question 21

Reflection coefficient in Starling (osmotic pressure) equation

Answer 21

• Range of 0-1
• 1 = membrane is impermeable to solute
• 0 = perfectly permeable to solute

Question 22

T/F: Dimensionless equations show overall trends

Answer 22

T

Question 23

The difference between inlet flow and outlet flow is equal to ______

Answer 23

Q_leak

(Vol flow of blood across semi-perm cap membrane)

Question 24

Flow through walls increases almost _______ w.r.t. K)f for constant frictional flow resistance

Answer 24

Linearly

(Q_leak/Q_,v,Poisseuille)