sodium and water balance Flashcards
what hormone controls water balance
ADH
does ADH make you pee more or less
less
how does ADH make you pee less
causes water to be reabsorbed from the renal tubules
- increased ADH causes a small volume of concentration urine
- decreased ADH causes a large volume of dilute urine
what is sodium balance controlled by
steroids
what is mineralocorticoid activity
effects of steroids on sodium balance
- sodium reabsorption in renal tubules in exchange for K/H
- too much mineralocorticoid activity means sodium gain
- too much mineralocorticoid activity means sodium loss
where is sodium confined to
extracellular fluid
what keeps the sodium in the extracellular fluid
a pump in the plasma membrane that keeps it there
what happens if you lose/gain sodium from the ECF
you lose/gain water with it
causes of increased sodium loss
- adrenal/kidney
- gut
- skin
causes of increased sodium intake
- some IV meds
- near-drowning
- malicious
symptoms of abnormal sodium
- altered consciousness
- confusion
- nausea
- vomiting
- fitting
what are the two kinds of stimuli for ADH release
- osmotic in health
- non-osmotic in disease
examples of non-osmotic stimuli
- hypovolaemia/hypotension
- pain
- nausea/vomiting
what is oedema
effective circulating volume depletion
-due to an altered balance of starling forces at capillary level
what happens in oedema
- ADH and aldosterone are secreted to try and restore the volume
- but much of retained water ends up in interstitial fluid
