fluid compartments Flashcards
oedema: define oedema, recall the causes of oedema, and explain the main types of exchange across the capillary wall
how does plasma leak out of capillaries
leaks out of pores between endothelial cells
what influecnes water being drawn into a normal capillary
colloid osmotic pressure (osmotic pressure due to plasma proteins)
what influences water being pushed out of a normal capillary
hydrostatic pressure (pressure exerted by volume of blood when in vessel)
what happens when hydrostatic pressure is lower than colloid osmotic pressure
interstitial fluid flows into vessel
what happens when hydrostatic pressure is greater than colloid osmotic pressure
plasma leaks out into interstitial space; increase in pore size
what does an increase in fluid leaking into interstitial space cause
oedema
define oedema
swelling of tissue because of excess interstitial fluid
what is the normal cycle of fluid exchange
blood plasma → interstitium → lymphatic vessels → blood via ducts (50%) or into nodes (50%)
what is oedema caused by
increased permeability of capillary walls to plasma proteins; leakage of plasma is greater than capacity of lymphatics to collect and return fluid
oedema as a cardinal sign of inflammation
infectious and inflammatory stimuli result in oedema
how does breast cancer surgery increase risk of oedema
lymph nodes removed so fewer for fluid to return to
how does elephantiasis increase risk of oedema
parasitic worm blocks lymph vessels so more difficult for fluid to return to
