Capillary exchange

Question 1

what are the 4 main force that influence capillary fluid at arteriole end of capillary?

Answer 1

1. capillary blood pressure (BP)
   –forces fluid out of caps into IF
2. interstitia fluid hydrostatic pressure (IFP)
   –forces fluid back into cap
   –“negative” value bc lymph system constantly drains fluid from tissues into blood stream–suction effect
   net HP–BP-IFP–+ve net hydrostatic pressure at the arteriole side of the capillary bed indicated it favors the movement of fluid out of the capillary
3. BCOP–oncotic pressure; encourages fluid to move back into vessels
4. interstital colloid osmotic pressure
   net osm pressure = BCOP-ICOP–+ve net osmotic pressure at the arteriole side of the capillary bed favors the movement of fluid back into the capillary

Question 2

net filtration pressure (arteriole) eq’n

Answer 2

(netHP) – (netOP)

Question 3

Forces influence capillary fluid exchange at the venule side of the capillary–pressure drops at venule end

Answer 3

ya

Question 4

what can edema be caused by?

Answer 4

increased perm of cap–>e.g. increases histamine release
decreases plasma protein
elevation of venous pressure
blockage of the lymph system

Question 5

net osmotic pressure?

Answer 5

netOP= BCOP-ICOP

Question 6

what is net filtration pressure at the venule?

Answer 6

netHP-netOP
where netOP=
where netHP=BP-IFP (int fluid pressure)

Question 7

With protein free fluid being reabsorbed back to the capillary at the distal end (proteins usually do not cross the membrane by diffusion)

Answer 7

ya

Question 8

Most of the fluid that force out from the arteriole will re-enter back to the venule

Answer 8

ya