Cardiology: Pulmonary and Systemic Oedema Flashcards
What makes up your extracellular fluid?
The interstitial fluid and the plasma fluid (in blood)
What is the function of your interstitial fluid?
The ‘go between’ body cells and the blood
What vessel regulates blood flow to the capillary bed?
Arterioles
What regulates flow in mesentary to the capillaries?
Precapillary sphincters
What passes throught the endothelium cells ?
Lipid soluble substances
What passes through the pores in the endothelium?
Water soluble substance
What is ultrafilration?
Exchanges across the capillary wall of protien free plasmanfluid
How is net filtration pressure measured?
Forces favouring filtration- forces opposing filtration
What forces governs ultra filtration from capillary to the interstitium?
Capillary hydrostatic pressure
Which force opposes filtration?
Capillary osmotic pressure
Why is the NFP at the arteriolar end higher than at the venule end?
Arteriole favours ultra filtration
Venule favours reabsoption
How is excess fluid returned to the circulation?
Via the lymph
What is significant about pulmonary hydrostatic pressure?
It is very low
What is oedema?
Accumulation of fluid in the interstitial space
What is pulmonary oedema?
Accumuation of fluid in the lung interstitium resulting in gas exchange compromise
What can cause oedema in the lungs?
Raised capillary pressure
Reduced plasma osmotic pressure
Lymohatic insufficiency
Changes in permeability
When does raised cap pressure ocure?
Arteriolar dilation Raised venous pressure eg: LVF- pulmonary RVF- peripheral oedema Prolonged standing- swollen ankles
When do reduced plasma proteins occure?
Malnutrition and malabsoprtion
Excess renal excretion e/g nephrotic syndrome
hepatic failure
What plasma protein level causes oedema?
Less than 30g/l
What can cause lymphatic insufficiency?
Filariasis- elephantiasis
Lymph node damage
What can cause changes in the capillary permeabliltiy?
Inflammation
Histamine - increases protein leakage
