pulmonary circulation Flashcards
pulmonary fluid balance: explain mechanisms that control fluid balance in the lungs, and the pathophysiological mechanisms that may lead to pulmonary oedema
how does plasma hydrostatic pressure change from the arterial to venous ends of the capillaries in pulmonary circulation
highest at very start of capillaries and decreases to venule end
what is the interstitial hydrostatic pressure in pulmonary circulation
negligible or negative
what is the plasma oncotic pressure in pulmonary circulation
should have more protein in blood vs outside, so drawing fluid into vessel
what is the interstitial oncotic pressure in pulmonary circulation
should have soluble ECM molecules drawing fluid out
what is the net movement of plasma fluid in pulmonary circulation
approx. 1mmHg out
what controls net movement of plasma fluid out of capillaries
lymphatics
what happens if production of plasma fluid exceeds maximum clearance of lymphatics
pulmonary oedema
Starling equation
[(hydrostatic pressure in) capillary - interstitium] - [(oncotic pressure in) capillary - interstitium]
effect of mitral valve stenosis on pulmonary circulation
pressure backs up so higher pressure in pulmonary circuit, causing higher plasma hydrostatic pressure and oedema
effect of liver failure on pulmonary circulation
decrease in plasma proteins, so lower plasma oncotic pressure, causing oedema to develop
effect of metastatic breast cancer on pulmonary circulation
spreads to lymph nodes, so lymphatics are less effective, causing oedema to develop whilst having no effect on pulmonary pressures
