Fluid-electrolyte physio Flashcards
what is formula for fluid balance
input-output
what is main predictor of water volume in ECF
Na, as water follows Na
what happens when add isotonic solution to body
adds ECF volume and ICF stays the same
4 consequences of dec. ECF vol
- low plamsa vol
- low blood volume
- low CO
- low BP
major consequence to high ECF volume
pulmonary edema
how does added isotonic solution dist in ECF
1:3 plasma to ISF
how does ISF volume change when change plasma vol? (2)
via changes in both hydrostatic and plasma oncotic pressure
what happens in hypoalbumenemia
ECF vol stays the same, but movement from plasma to ISF
how does body sense Na and ECF balance
via changes in effective arterial volume
what is effective arterial volume
volume of blood in arterial tress that is effectively perfusing tissues
what are sensors of effective arterial volume
baroreceptors (sense stretch)
where are baroreceptors located
- central arteries
- renal afferet art.
- cardiac atria and vents
4 possible responses to baroreceptors
- SNS
- RAAS system
- ADH
- atrial naturetic peptide - to lower
3 main functions of angiotensin 2
- art. contstriction
- renal Na absorption, both direct and via adlosterone
- increased thirst and ADH
3 effects of Ang2 induced eff arteriole constriction
- incr glom cap pressure
- changes in peritubular cap. factors
- net effect of wasted out, but Na kept in
3 pathologies of chronic RAAS activity
- atheriosclerois
- cardiac remodelling
- renal scarring post-injury
what is typical Na intake in a day
150mmol