click below
click below
Normal Size Small Size show me how
USMLE
Renal Physiology 2
Question | Answer |
---|---|
actions of angiotensin II? | potent vasoconstriction release of aldosterone from adrenal cortex release of ADH from posterior pituitary stimulates hypothamus - increases thirst overall serves to increease intravascular volume and BP |
what may be released from atria as a check on the RAA system, e.g. in CHF? | ANP |
what cells secrete renin? | juxtaglomerular cells - in response to decreased renal BP, decreased Na+ delivery to distal tubule, and increased sympathetic tone |
how can NSAIDs cause acute renal failure in high vasoconstrictive states? | by inhibiting the renal production of prostaglandins, which keep the afferent arterioles vasodilated to maintain GFR |
where does ADH bind? what is the result? | binds to receptors on principal cells, causing an increase in the number of water channels/aquaporins and increased H2O reabsorption |
what is ANF secreted in response to? what does it do? | secreted in response to increased atrial pressure, causes increased GFR and increased Na+ excretion |
what effect does aldosterone have? | secreted in response to decreased blood volume (via AT II) and increased plasma K+ - causes increased Na+ reabsorption and increased K+ and H+ secretion |
angiotensin II causes increased absorption of what? | Na+ and HCO3- |
primary disturbance in metabolic acidosis? | decreased HCO3- (causes hyperventilation/ decreased PCO2) |
primary disturbance in metablic alkalosis? | increased HCO3- (causes hypoventilation/ increased PCO2) |
primary disturbance in respiratory acidosis? | increased PCO2 (causes increased renal HCO3- absorption) |
primary disturbance in respiratory alkalosis? | decreased PCO2 (causes decreased renal HCO3- absorption) |
acidosis with PCO2 >40? | respiratory acidosis |
acidosis with PCO2 <40? | metabolic acidosis with compensation |
alkalosis with PCO2 <40? | respiratory alkalosis |
alkalosis with PCO2 >40? | metabolic alkalosis with compensation |
causes of respiratory acidosis? | hypoventilation - airway obstruction, acute/chronic lung disease, opiods, narcotics, sedatives, weakening of respiratory muscles |
causes of anion gap metabolic acidosis? | MUD PILES Methanol Uremia Diabetic ketoacidosis Paraldehyde or Phenformin Iron tablets or INH Lactic acidosis Ethylene glycol Salicylates |
causes of non-anion gap metabolic acidosis? | diarrhea, glue sniffing, renal tubular acidosis, hyperchloremia |
how do you calculate ion gap? | Na+ - (Cl- + HCO3-) |
causes of respiratory alkalosis? | hyperventilation, aspirin ingestion (early) |
causes of metabolic alkalosis? | vomiting, diuretic use, antacid use, hyperaldosteronism |
Winter's formula? | PCO2 = 1.5(HCO3-) + 8 +/-2 |
type of metabolic disturbance commonly seen in cardiopulmonary arrest? | mixed acidosis |