Micocirculation

Question 1

Thoroughfare or bypass vessels?

Answer 1

let blood get from arterial to venous side without going through one of more capillaries

Question 2

Fick’s law of diffusion?

Answer 2

J=PS(dc/dx)

Question 3

PS?

Answer 3

permability and surface area

Question 4

dc/dx?

Answer 4

concentration difference between blood and interstitium

Question 5

Flow limited?

Answer 5

diffusion is fast and transport is only changed by the rate of blood perfusing a tissue

Question 6

Rate limited?

Answer 6

larger molecules have difficulty moving through pores and thus diffusion is rate limited

Question 7

Pathologic diffusion- penumonia?

Answer 7

oxygen and CO2 are normally flow limited
interstitial fluid adds diffusion distance and viscosity
diffsuion of gases shifts from flow limited to diffusion limieted

Question 8

Water movement depends on?

Answer 8

pressure differences across the capillary membrane

hydraulic conductivity and area of diffusion

Question 9

Starling-Landis equation?

Answer 9

J=KA[(CHP-THP)-(COP-TOP)]

Question 10

CHP?
THP?
TOP?
COP?

Answer 10

capillary hydrostatic pressure
Tissure hydrostatic pressure
tissure oncotic pressure
capillary oncotic pressure

Question 11

Oncotic pressure?

Answer 11

force of water trying to dilute protein in a solution

Question 12

California gangster rule?

Answer 12

tissue hydrostatic and tissue oncotic pressure (THP and TOP) are essential 0 in normal situation

CHP=COP normally therefore

Question 13

4 pressures at equilibrium?

Answer 13

CHP+TOP=COP+THP

Question 14

Increased capillary hydrostatic pressure causes edema?

Answer 14

higher Capillary Hydrostatic pressure (CHP) causes water to shift out of the capillary since it’s higher than COP

Question 15

examples of higher CHP?

Answer 15

heart failure and DVTs

Question 16

Low plasma proteins cause edema?

Answer 16

less protein in capillary means COP decreases relative to CHP and water flows out of the capillary

Question 17

examples of low plasma proteins?

Answer 17

Quashiorkor, severe burns

Question 18

Lymphedema?

Answer 18

sinus infection plugs up lymph drainage causing proteins to accumulate in intersitial fluid

Therefore TOP increases and CHP stays the same but the 2 of them become larger relative to COP and water flows out of the capillary

CHP+ TOP> COP