Flashcards in Sodium disorders Deck (65)
Normal serum Na+?
Normal plasma/serum osmolality?
Eqn to estimate plama/serum osmolality?
Na x 2 + BUN/2.8 + Gluc/18
Main contributor to serum osmolality?
Symptoms of hypo/hypernatremia are due to effects on which orhan?
Sodium abnormalities are usually caused by ____________ NOT ___________.
Extracellular hyp-O-osmolality have what effent on neurons?
Sx if Na+
Sx if Na+ = 115-120:
Sx if Na+
More severe sx in fast or slow hyp-O-natremia?
brain has less time to adapt
Effect of hyp-ER-natremia on neurons?
Sx of hyp-ER-natremia?
Decreased brain volume due to hyp-ER-natremia can have what effect on vasculature?
rupture cerebral vessels
Clinically significant water shift occurs with 30-35 mosm/kg osmolar gradient between plasma and brain; what is the corresponding rise in serum Na+?
Hormone responsible for maintenance of plasma osmolality:
Where is ADH produced?
supraoptic and paraventricular nuclei of hypothalamus
Where is ADH stored and released?
Osmotic stumuli of ADH release:
INCREASED plasma osmolality
Non-osmotic stimuli of ADH release:
hypovolemia --> baroreceptors
What receptor binds ADH to release aquaporin 2 to luminal membrane?
Where does this occur?
V2 (activates protein kinase)
With high presence of ADH:
Urine osmolality = ?
Plasma osmolality = ?
**water flows out of tubule back into blood
In low/absent ADH state:
Urine osmolality= ?
Blood osmolality= ?
**water excreted in urine
Physiologic responses to HIGH plasma osmolality:
concentration of urine --> high urine osmolality
Physiologic response to LOW plasma osmolality:
No ADH release
Loss of free water -- collecting tubules impermeable
Low urine osmolality -- dilute urine
Plasma osmolality maintained within __%.
Indicator of the presence of ADH?
What generally tells you what the kidney THINKS about the body's volume status?
Range of urine osmolality in a normal kidney?