Exam 2 Physio

Question 1

Hypercalcemia impact on body

Answer 1

decreased excitability
sedation
shortened QT interval
more depolarized, but takes longer to fire

Question 2

Hypocalcemia impact on body

Answer 2

increased excitability

increased Na+ membrane permeability

Question 3

Nephron pH and Ca2+ resorption

Answer 3

decreased pH displaces Ca2+ from albumins (via H+ competition)
increases Ca2+ filtered and Ca2+ resorbed

Question 4

Ca2+ resorption along tubule

Answer 4

prox-passive diffusion into cell, Ca2+/Na+ ATPase into blood
Loop of Henle-(+) lumen drives passively in (dependent on Na+ resorption)
Distal tubule-PTH increases apical channels/Vit D increases Ca2+ ATPase and calbindin

Question 5

Causes of increased Ca2+ resorption

Answer 5

increased PTH/Vit D
decreased ECFV/BP
metabolic acidosis
ADH

Question 6

Causes of decreased Ca2+ resorption

Answer 6

decreased serum phosphate/PTH
increased ECFV/BP
metabolic alkalosis

Question 7

Phosphate resorption in tubule

Answer 7

proximal tubule-Na+/Phosphate cotransporter

increased luminal H+ inhibits transport

Question 8

Effectors of phosphate

Answer 8

PTH decreases
ANP decreases
volume expansion decreases (due to Na+ dependence)

Question 9

Effects of PTH

Answer 9

increased bone resorption (Ca2+/Phos in serum)
increased phosphate excretion
decreased calcium excretion
increased calcitrol (causes more Ca2+/phos GI absorption)

Question 10

Impact of hypermagnesemia on body

Answer 10

decreased excitability

cardiac arrest/respiratory insufficiency

Question 11

Impact of hypomagnesemia on body

Answer 11

hyperexcitability (tetany)
cardiac arrhythmia
increased peripheral vascular resistance (vasoconstriction)

Question 12

Magnesium regulation

Answer 12

PTH increases (Ca and Mg use same channel)
diuretics decrease resorption

Question 13

Henderson Hasselbach eqn

Answer 13

pH=pKa + log (bicarb/0.03PCO2)

Question 14

Causes of anion gap metabolic acidosis

Answer 14

MUDPILES

Question 15

Causes of hyperchloremic metabolic acidosis

Answer 15

diarrhea
renal tubular acidosis
CAI's
Addison's
pancreatitis

Question 16

Winter’s eqn

Answer 16

PCO2=1.5*bicarb +8
if over, then resp acidosis as well
if under, then resp alkalosis

Question 17

Eqn for tx of metabolic acidosis (bicarb deficit)

Answer 17

BD=0.5wt(desired bicarb-initial bicarb)

Question 18

Causes of metabolic alkalosis

Answer 18

vomiting
alkaline drugs
aldosterone (H+ excretion)
ECFV depletion
diuretics