Flashcards in First Aid Deck (34):
How do prostaglandins affect filtration fraction?
Dilate the afferent arteriole → increase RPF & GFR to keep FF constant.
NSAIDs decrease RPF & GFR.
How does angiotensin II affect filtration fraction?
Constricts the efferent arteriole → decreases RPF, increases GFR so FF increases.
ACEIs increase RPF, decrease GFR & FF.
What is the defect in Hartnup disease?
Deficiency of neutral AA/Na co-transporters in the proximal tubule. Causes pellagra-like symptoms from decreased absorption. Treat with high protein diet and nicotinic acid.
What is the defect in Fanconi syndrome?
Problem with reabsorption in proximal tubule of amino acids, glucose, HCO3-, and phosphate. Can cause metabolic acidosis.
What is the defect in Bartter syndrome?
Defective reabsorption in the thick ascending loop of Henle, affects the NK2C transporter. Causes hypokalemia, metabolic alkalosis, and hypercaciuria.
What is the defect in Gitelman syndrome?
Defective reabsorption of NaCl in the distal convoluted tubule. Causes hypokalemia & metabolic alkalosis, but no hypercalciuria. Less severe than Bartter syndrome.
What is the defect in Liddle syndrome?
Increased Na+ reabsorption in the distal and collecting tubules by the ENaC. Causes HTN, hypokalemia, metabolic alkalosis, decreased aldosterone. Treated with Amiloride.
What causes the release of renin?
Decreased Na+ delivery sensed by the macula densa cells.
Activation of beta-1 receptors.
What are the actions of angiotensin II?
Vasoconstriction by AT1 receptors → increase in BP.
Constriction of efferent arteriole of the glomerulus → increases FF by increasing GFR.
Release of aldosterone.
Release of ADH.
Increase in Na/H exchanger in the proximal tubule.
Stimulates the hypothalamus to cause thirst.
What are the actions of aldosterone?
Increases expression of the Na+ channel, Na/K ATPase, principal cell K+ channels, and intercalated cell H+ ATPases → creates a favorable gradient for Na+ and H2O absorption.
What are the actions of ADH?
Causes insertion of AQP2 into the lumenal membrane in the collecting duct principal cells → increased H2O reabsorption.
What are the actions of ANP?
Released from the atria due to increased volume. Relaxes vascular smooth muscle → increases GFR, decreases renin release. Net loss of Na+.
What are the actions of PTH?
Increased Ca2+ reabsorption in the DCT, decreased phosphate reabsorption in the PCT, and increased vitamin D production.
What causes K+ to leave cells (hyperkalemia)?
Digitalis, hyperosmolarity, insulin deficiency, lysis of cells, acidosis, beta-adrenergic antagonist.
What causes K+ to enter cells (hypokalemia)?
Hypo-osmolarity, insulin, alkalosis, beta-adrenergic agonist.
Causes of respiratory acidosis
Airway obstruction, acute lung disease, chronic lung disease, opioids, sedatives, weakening respiratory muscles.
Causes of metabolic acidosis with increased anion gap
MUDPILES: methanol, uremia, diabetic ketoacidosis, propylene glycol, iron tablets, lactic acidosis, ethylene glycol, salicylates
Causes of metabolic acidosis with normal anion gap
HARD-ASS: hyperalimentation, Addison disease, renal tubular acidosis, diarrhea, acetazolamide, spironolactone, saline infusion
Causes of respiratory alkalosis
Hysteria/panic attack, hypoxemia, salicylates (early), tumor, pulmonary embolism
Causes of metabolic alkalosis
Loop diuretics, vomiting, antacid use, hyperalosteronism
What is the effect of Type 1 renal tubular acidosis?
Defect in the ability of alpha intercalated cells to secrete H+ → less bicarbonate reabsorption → metabolic acidosis. Can cause hypokalemia, increases the risk for calcium phosphate kidney stones. Urine pH > 5.5.
What are the causes of Type 1 RTA?
Amphotericin B toxicity, analgesic nephropathy, multiple myeloma, congenital anomalies of urinary tract.
What is the effect of type 2 renal tubular acidosis?
Defect in the ability of the proximal tubule to reabsorb HCO3- → metabolic acidosis. Can cause hypokalemia, increases risk for hypophosphatemic rickets. Urine pH < 5.5
What are the causes of type 2 RTA?
Fanconi syndrome, lead, aminoglycosides, carbonic anhydrase inhibitors.
What is the effect of type 4 renal tubular acidosis?
Hypoaldosteronism, aldosterone resistance, or K+-sparing diuretics. Hyperkalemia → reduces ammonia secretion → decreases buffering capacity. Urine pH < 5.5
What are the causes of RBC casts in the urine?
Glomerulonephritis, ischemia, malignant hypertension.
What are the causes of WBC casts in the urine?
tubulointerstitial inflammation, acute pyelonephritis, transplant rejection
What are the causes of fatty casts (oval fat bodies) in the urine?
What is the cause of granular (muddy brown) casts in the urine?
Acute tubular necrosis
What is the the cause of waxy casts in the urine?
Advanced renal disease/chronic renal failure
What is the cause of hyaline casts in the urine?
Nonspecific, can be normal
What are the nephrotic syndromes?
Minimal change disease
What are the nephritic syndromes?
Acute post-streptococcal glomerulonephritis
Rapidly progressive glomerulonephritis