Ex 3 Fluid Compartments, Capillary dynamics, and control of circulation Flashcards
How much of the body weight is fluid?
2/3
How much of the body fluid is extracellular?
1/3
How much of the extracellular body fluid is interstitial fluid?
4/5 of ECF
How much of ECF is plasma?
1/5 of ECF
What does the area between vessels and cells include?
collagen and other filaments
What is the pressure of interstitial fluid?
P< 0 mmhg
What is the average functional capillary pressure?
17 mmHg
What controls the fluid movement out of capillaries into the interstitium?
Starling forces
What are the factors influencing the rate of fluid movement across membrane?
- Hydraulic permeability of the capillary
- Surface area of the capillary
- Pressure differential across the capillary membrane
What is the net force acting on water?
Kf x NFP or Kf((Pc-piec)-(Pi-piei))
Where is the majority of filtered fluid reabsorbed?
90% at the venous side of the capillary bed
What is edema?
Excess fluid accumulation in the cavities or tissues of the body
What causes edema?
- increased capillary hydrostatic pressure
- decreased plasma protein concentration
- increased “leakiness” of capillary
- obstruction of lymphatic vessels
What is drain fluid from interstitial space called?
Lymphatics
What is absorbed by lymphatics?
10% of fluid, remove excess interstitial protein, bacteria and particles
