Renal Flashcards
what nephron structures does the cortex contain?
glomeruli, proximal and distal tubules
what nephron structures does the medulla contain?
loops of Henle and collecting ducts
follow the course of renal blood supply from renal artery to afferent arteriole
renal artery –> segmental artery –> lobar artery –> interlobar artery –> arcuate artery –> interlobular artery –> afferent arteriole
capillary loops supplying tubules of juxtamedullary nephrons
vasa recta
capillary loops supplying tubules of cortical nephrons
tubular plexus
which layer of the glomerular filtration barrier is the size barrier?
capillary endothelium
which layer of the glomerular filtration barrier is the negative charge barrier?
basement membrane
which layer of the glomerular filtration barrier contains heparin sulfate?
basement membrane (negative charge barrier)
which portion of the nephron has brush borders?
proximal tubule
difference between cortical and juxtamedullary nephrons?
cortical nephrons have short loops of Henle that only have a descending thin limb; juxtamedullary nephrons have long loops with both ascending and descending thin limbs
thin segments of loop of Henle are lined with what type of cells?
simple squamous epithelium
which portion of nephrons passively reabsorbs water?
thin descending loop of Henle
concentrating segments of the nephron
thin descending loop of Henle and collecting duct
segments of the nephron that are water impermeable
thin ascending loop of Henle, thick ascending loop of Henle, early distal convoluted tubule
what segment of the nephron do loop diuretics (furosemide) work on, and what transporter do they target?
thick ascending loop of Henle, Na+/K+/2Cl- cotransoprter
what segment of the nephron do thiazides work on, and what transporter do they target?
early distal convoluted tubule, Na+/Cl- cotransporter
what segment of the nephron does aldosterone work on, and what is its mechanism of action?
late distal tubule, aldosterone causes insertion of sodium channels in lumen
what segment of the nephron does ADH work on, and what is its mechanism of action?
collecting ducts, ADH inserts aquaporin water channels in lumen
mechanism of diabetes insipidus
absence of ADH leads to excretion of water, leading to polyuria and hypotonic urine
what are JG cells?
specialized smooth muscle cells in the afferent arteriole, produce renin
what part of the JG apparatus senses Na and Cl concentrations?
macula densa
role of macula densa
part of JG apparatus, detects Na and Cl concentration for JG cells
when do JG cells secrete renin?
when renal blood pressure decreases, when NaCl delivery to distal tubule decreases, and when sympathetic tone increases
what kind of cells in kidney release erythropoietin?
interstitial cells
does renal tubular disease lead to acidosis or alkalosis and why?
acidosis because of failure of H+ ion excretion
explain the 60-40-20 rule of fluid distribution in body
60% of body weight is water
40% of body weight is intracellular fluid
20% of body weight is extracellular fluid
explain the mechanism of tuberoglomerular feedback
in response to an elevation of perfusion pressure, increased fluid is filtered, leading to increased delivery of NaCl to the macula densa –> increase in vascular resistance
what molecules increase GFR?
nitric oxide and prostaglandins
what molecules decrease GFR?
norepinephrine, epinephrine, endothelin, angiotensin II
what hormone increases Na+ reabsorption in the proximal tubule? what enzyme does it target?
angiotensin II, Na+/H+ countertransporter
what hormone increases Na+ reabsorption in the late distal tubule?
aldosterone
what hormone increases water reabsorption in the collecting duct?
ADH
what are the effects of PTH?
decreased phosphorus reabsorption and increased calcium reabsorption
clinical picture of Liddle syndrome (5)
- hypertension
- hypokalemia
- metabolic alkalosis
- low plasma renin
- low aldosterone
pathogenesis of Liddle syndrome
mutation in renal ENaC leading to constitutive expression –> increased reabsorption of sodium –> hypertension
agent used to treat Liddle syndrome
amiloride
inheritance of Liddle syndrome
autosomal dominant
Gitelman and Bartter syndromes: inheritance, common clinical presentation (2), presentation unique to Bartter syndrome
autosomal recessive; hypokalemia and metabolic alkalosis; hypercalciuria
pathogenesis of Bartter syndrome
reabsorptive defect in thick ascending loop of Henle, affects Na+/K+/2Cl- cotransporters
pathogenesis of Gitelman syndrome
reabsorptive defect of Na+/Cl- cotransporter in distal convoluted tubule
which Mendelian hypertension disease causes hypokalemia, metabolic alkalosis, AND hypercalciuria?
Bartter syndrome
define respiratory acidosis vs alkalosis
resp. acidosis: pCO2 > 40 mmHg
resp. alkalosis: pCO2 < 40 mmHg
define metabolic acidosis vs alkalosis
metab. acidosis: HCO3- < 24 mmol/L
metab. alkalosis: HCO3- > 24 mmol/L
compensation equation for metabolic acidosis
pCO2 = 1.5[bicarbonate] + 8 pCO2 = last 2 digits of pH
compensation equation for metabolic alkalosis
pCO2 = 0.9[bicarbonate] + 9
compensation equation for respiratory acidosis
acute: bicarb increases 1 mmol/L per 10 mmHg increase in PaCO2
chronic: bicarb increases 4 mmol/L per 10 mmHg increase in PaCO2
compensation equation for respiratory alkalosis
acute: bicarb decreases 2 mmol/L per 10 mmHg decrease in PaCO2
chronic: bicarb decreases 4 mmol/L per 10 mmHg decrease in PaCO2
_________ in plasma osmolarity and _________ in blood volume trigger increased ADH release
increase, decrease
which cancer can release ADH?
small cell lung
equation for GFR using serum creatinine
GFR ~ 100/Cr
_________ is the most important stimulus for aldosterone secretion relating to sodium balance, and it is dependent upon __________ secretion
angiotensin II, renin
the systemic response to decreased ECF volume involves ________ and ________ activation, activation of ________, and increased ________
baroreceptor, sympthetic nerve, RAAS, ADH
what is FENa?
how much filtered sodium is excreted
in kidney disease, there is ____ serum calcium, ____ serum phosphorus, feedback to _____, leading to _____
low, retention of, parathyroid gland, high PTH release
classic presentation of glomerular disease (3)
hematuria, loss of GFR, proteinuria
classic presentation of nephrotic syndrome (4)
proteinuria, hypoalbuminemia, edema, hyperlipidemia
classic presentation of nephritis (4)
mild proteinuria, hematuria (RBC casts), hypertension, edema
hematuria accompanying a URI
IgA nephropathy
kidney problem associated with Henoch-Schonlein purpura
IgA nephropathy
cola-colored urine
post-streptococcal glomerulonephritis
subepithelial “hump-like” immune complex deposits on EM
post-streptococcal glomerulonephritis
crescentic glomerulonephritis
rapidly progressive glomerulonephritis
pathogenesis of Goodpasture’s syndrome
rapidly progressive glomerulonephritis caused by antibodies against GBM and alveolar basement membrane (may present as pulmonary-renal syndrome)
vasculitis that is C-ANCA positive and renal biopsy shows crescentic glomerulonephritis WITHOUT immune deposits, with sinusitis, nasal lesions, and hemoptysis
Wegener’s granulomatosis
vasculitis that is P-ANCA positive and renal biopsy shows crescentic glomerulonephritis with necrotizing granulomatous inflammation, asthma, eosinophilia
Churg-Strauss syndrome
vasculitis that is P-ANCA positive and renal biopsy shows crescentic glomerulonephritis without granulomatous inflammation and no asthma
microscopic polyangiitis
3 primary nephrotic glomerular disease
membranous nephropathy, focal segmental glomerulosclerosis (FSGS), minimal change disease
most common cause of nephrotic syndrome in children
minimal change disease
nephrotic syndrome associated with Hodgkin’s lymphoma
minimal change disease
what two nephrotic syndromes cause effacement of the podocyte foot processes?
minimal change disease and focal segmental glomerulosclerosis (FSGS)
diagnose: child with proteinuria >3.5 g/day, effacement of the podocyte foot processes on EM
minimal change disease
most common cause of nephrotic syndrome in Caucasian adults
membranous nephropathy
secondary causes of membranous nephropathy
hepatitis B, SLE, solid tumors, drugs
nephrotic syndrome that shows spike and dome appearance on EM, thickened GBM
membranous nephropathy
most common cause of nephrotic syndrome in African Americans and Hispanics
focal segmental glomerulosclerosis (FSGS)
nephrotic syndrome associated with HIV
focal segmental glomerulosclerosis (FSGS)
glomerular disease that can present with nephrotic and nephritic features
membranoproliferative glomerulonephritis
common cause of diffuse proliferative glomerulonephritis
SLE