Module 2.4 - Biolfuid Transport IV (Capillary Flow) Flashcards
Capillary “leakage”
Capillaries act as semi-permeable membranes through which fluid transfer and solutes travel
Fenistrative capillaries
Have more openings in capillary membrane
Inverse of resistance to flow measured across membrane
Filtration coeff (1/R = K_f)
T/F: Overall area for convection is much greater in capillary than for diffusion
F: Much greater for diffusion than convection (very limited SA for convection to occur)
2 pressures within capillaries that drive water flow
Hydrostatic pressure (left vent contraction)
Osmotic pressure
How is osmotic pressure generated?
When semi-perm membrane has diff concentrations of same substance on diff sides
Interstitial fluid
Fluid on outside of capillaries (in tissues)
T/F: Diameter of capillary is only large enough to allow one cell to move through vessel at a time
T
T/F: Any type of cell can move across different kinds of capillary membranes
F: cells move across the membrane if they have right diameter
Van Hoff eqn
Osmotic pressure = cRT
c = concentration dissolved solute
R = gas cst
T = temp
T/F: Van Hoff eqn applicable across ideal and non-ideal cases
F: Ideal or ideally dilute
T/F: Starling equation was empirically derived
F: Semi-empirical
T/F: Hydrostatic pressure inside capillary (P_c) is constant across any capillary
F: NOT constant, decreases as it travels through capillaries
Hydrostatic pressure in capillaries is _______ below the heart, and ________ above the heart
Higher
Lower
T/F: Interstitial pressure (P_s) is slightly negative
T
T/F: Osmotic P inside capillary is driven principally by lipid content
F: Protein content
On venule side of capillary, the osmotic process starts to ______ and fluid moves _______ the tissues
Reverse
Back into
Lymphatic system
Another way (besides circulatory system) of removing interstitial fluid from tissues (low in protein content, high in salts, AAs, CO2 and waste)
T/F: Lymph nodes shrink during infection
F: They swell - leukocytes (WBCs) accumulate in lymph nodes during infection
T/F: Lymph system has one-way valves like veins, and lymph fluid gets moved back to the heart through muscle action
T
Reflection coefficient in Starling (osmotic pressure) equation
- Range of 0-1
- 1 = membrane is impermeable to solute
- 0 = perfectly permeable to solute
T/F: Dimensionless equations show overall trends
T
The difference between inlet flow and outlet flow is equal to ______
Q_leak
(Vol flow of blood across semi-perm cap membrane)
Flow through walls increases almost _______ w.r.t. K)f for constant frictional flow resistance
Linearly
(Q_leak/Q_,v,Poisseuille)
