others Flashcards
causes of Fanconi syndrome
- hereditary defects (Wilson disease, tyrosinemia, glycogen storage disease, cystinosis)
- iscemia
- multiple myeloma
- nephrotoxins/drugs (ifosfamide, cisplatin, tenofovir, lead poisoning, expired tetracyclines)
proportion of Na2+ reabsorption in proximal convoluted tubule, in thick ascending loop of Henle, in early distal convoluted tubule, collecting tubules
- proximal convoluted tubule –> 65-80%
- thick ascending loop of Henle –> 10-20%
- early distal convoluted tubule –> 5-10%
- collecting tubule –> 3-5%
Total body water in higher than 60% of body weight in ….
and lower in…
higher –> newborns and adult males
lower –> adult females and adults with large amount of adipose tissue
anions and cations of ICF
cations: K, Mg
anions: protein and Organin phosphates (ATP, AMP, ADP)
anions and cations of ECF
cations: Na
anions: CL, HCO3, plasma proteins (in plasma)
measure of ICF and interstitial fluid
ICF = TBW-ECF INTERSTITIAL = ECF-PLASMA
Isosmotic volume expansion - example, ECF volume, ICF volume, ECF osmolarity, HCT, (Na), BP
example: isotonic NaCL infusion ECF volume: increased ICF volume: - ECF osmolarity: - HCT: decreased (dilution, and no RBC shinkening) (Na): - BP: increased
isosmotic volume contraction - example, ECF volume, ICF volume, ECF osmolarity, HCT, (Na)
example: diarrhea ECF volume: decreased ICF volume: - ECF osmolarity: - HCT: increased (Na): - BP: decreased
Hyperosmotic volume expansion - example, ECF volume, ICF volume, ECF osmolarity, HCT, (Na), BP
example: High NaCl intake ECF volume: increased ICF volume: decreased ECF osmolarity: increased HCT: decreased (dilution and shrinkage) (Na): increased BP: increased
Hyperosmotic volume contraction - example, ECF volume, ICF volume, ECF osmolarity, HCT, (Na), BP
example: sweating, Fever, Diabetes insipidus ECF volume: decreased ICF volume: decreased ECF osmolarity: increased HCT: - (because shrinkage) (Na): increased BP: decreased
hyposmotic volume expansion - example, ECF volume, ICF volume, ECF osmolarity, HCT, (Na), BP
example: SIADH ECF volume: increased ICF volume: increased ECF osmolarity: decreased HCT: - (because water into RBCs) (Na): decreased BP: increased
Hypoosmotic volume contraction - example, ECF volume, ICF volume, ECF osmolarity, HCT, (Na), BP
example: Adrennal insuficiency (excrete more NaCL than water) ECF volume: decreased ICF volume: increased ECF osmolarity: decreased HCT: increased (Na): decreased BP: decreased
renal blood flow is …..% of the cardiac output
25%
beside NO and PGEs, which else can cause vasodilation of renal arterioles
Bradykinin
RBF autoregulation - range, mechanism
range 80-200 mm Hg
mechanis: a. Myogenic mechanism (afferent contract in response to stress
c. Tubuloglomerular feedback: increased glomerular pressure –> more fluid to macula densa –> afferent constriction
GFR vs Creatinine according to age
GFR decreases with age, but serum Cr reamains constant because of decreased muscle mass
Increased or decreased filtration fraction - reabsorption vs secretion
increased –> increased (plasma protein) –> increased reabsorption in PCT
decreased –> decreased (plasma protein) –> decreased reabsorption in PCT
causes of increased glomerular P
dilation of afferent or constriction of efferent
causes of increased Bowman P
ureter constriction
symathetic effect on Renal arterioles
constricts afferent –> decreases GFR, RPF, but not the FF
PAH - rate of secretion
at low plasma concentrations, the secretion rate increases as the plasma concentration increases –> once the carriers are saturated, further increases in plasma concentration do not cause further increases in the secretion rate
equation for the fraction of the filtered water that has been reabsorbed
and example
fraction = 1 - (1/(inulin concentration in tubular/plasma))
if inulin concentration/plasma concentration = 2 –> 50% of the water has been reabsorbed
equation for the fraction of the filtered load (of a substance x) remaining at any point along the nephron
(TF/P)x/(TF/P)inulin
effects of ECF volume on proximal tubular reabsorption
- ECF volume conraction –> increases peritubular capillary protein concentration and decreases P –> increased reabsroption
- ECF volume expansion –> decreased peritubular capillary protein concentration and increased P –> decreased reabsorption
K+ balance is achieved when the
urinary excretion of K+ exactly euals intake K+ in the die
Proportion of K+ that is reabsorbed in PCT, thick ascending, and roloe of colecting duct
PCT: 67% (along with Na+ and H20 thick ascending: 20% collecting duct (H,K+ ATPase on a cells): occurs only on low k+ depletion
factors that increased/decreased distal K+ secretion
- -> electrochemical driving force for K+ accross the luminal membrane is increased or dicreased
1. K+ diet: if high –> secretion, if low –> not
2. aldosterin
3. ph, alkalosis –> secretion, acidosis, not (because K+/H+ exchanger)
4. diuretics: K sparing decrease secretion, thiazide and diuretics increase secretion
5. . Luminals anions –> excess anions (K+) increase K+ secretion
Urea reabsroprtion in nephron
50% from PCT
ADH increased urea permeability in inner medullary collecting duct –> urea recycling in the inner medulla –> osmotic gradient
urea excretion varies with urine flow rate –> at high levels of water reabsroption –> great urea reabsorption –> decreased urea excretion
Phosphorus and Mg2+ excretion in nephron
Pi: 85 % from PCT. PTH decreases this
Mg2+ reabsorbed in PCT, thick ascening DCT
Mg2+ vs Ca2+ in nephron
in thick ascending, Mg2+ and Ca2+ compete for reabsorption –> hypercalcemia causes Mg2+ excretion, hypermagnisemia causes Ca2+ excretion
Ca2+ reabsorption - percentages
PCT and ascending –> 90%
PTH on distal
regulation of urine in Water deprivation
increases plasma OSM –> anterior hypothalamus osmoreceptors –> ADH from posterior pituitary –> increases water reabsorption –> increases urine OSM and decrease urine volume –> decrease plasma OSM back to normal
regulation of plasma and urine osmolarity in Water intake
decreases plasma OSM –> decrease ADH from posterior pituitary –> decrease water reabsorption –> decreases urine OSM and increases urine volume –> increases plasma OSM back to normal
beside ADH permeability, ADH in nephrons also
increases corticopappilary osmotic gradient (stimulates NACL reabsroption in thick ascending, urea recycling)
Free water clearance - everything
is used to estimate the ability to concentrate or dilute the urine
= urine flow rate - osmolar clearance (clearance of evertything)
low ADH –> free H20 clearance in + (hyposomotic urine)
high ADH –> free H20 clerance in - (hyperosmotic urine)
isosmotic urine –+ free H2O is 0
causes of positive and negative free water clearance
positive –> primary polydipsia, CDI, nephrogenic DI
negative –> water deprivation, SIADH
ADH receptors
v1 - vessels
v2 - principal cells
thiazide vs loop diuretics according to urine dilution and concatenation
decreased dilution: both
decreased concentration: only loop (decreases corticopapillary gradient)
MCC of sturvite stone
Klebsiella + Proteus
