Capillary Permeability Flashcards
What 4 factors affect rate of diffusion?
1-Temperature
2-Concentration gradient
3-Size of solute
4-Viscosity of solution
Which system is considered the distribution vessels?
Arterial
Which system is considered the collection vessels?
Venous
What are considered the exchange vessels?
Capillaries
What is crystalline osmotic pressure?
Small solutes affecting pressure. More solute molecules=higher pressure
What is oncotic pressure?
Insoluble proteins in vessels that draw water into the vessel. Essentially osmotic pressure
What is hydrostatic pressure?
Force pushing fluid out of capillary
What is starlings law used for?
Calculate net filtration pressure (forces pushing out - forces pushing in)
Which forces pull fluid in?
Osmotic/oncotic pressure of capillary
Hydrostatic pressure from interstitial fluid
Which forces push fluid out?
Hydrostatic forces from capillary
Osmotic pressure of interstitial fluid
What happens to blood velocity and pressure as cross sectional area increases approaching capillaries?
Velocity and pressure go down
What do precapillary sphincters do when open?
Allow blood to flow through true capillaries
What do precapillary sphincters do when closed?
Channel blood through metarteriole and throuroughfare channel to bypass true capillaries
How much fluid is filtered out of the arteriolar side of capillary beds?
20 liters
How much fluid is reabsorbed on the venue side of capillary beds?
17 liters
