Kidney 1 Flashcards
where is the upper pole of the kidney?
12th thoracic vertebra
where is the lower pole of the kidney?
3rd lumbar vertebra
how many vertebral bodies doe a kidney span?
3.5 vertebral bodies
renal blood flow gets how much of cardiac output?
20% of CO
what is the normal GFR
100-125 ml/min
if you have a problem with the renal artery what is compromised?
the entire kidney
what nephron as associated w/ maximal ability to concentrate urine?
juxtamedullary nephrons
what is the beginning of an individual nephron
glomerulus
what region of the glomerulus is nonvascular w/ some contractile components. Sensitive to injury by certain diseases
mesangial region
portion of distal convoluted tubule. forms basis for glomerular tubular feedback.
macula densa
cells that aren’t inside the glomerulus. Cells aren’t a part of the vascular epithelium
extraglomerular mesangial cells
part of epithelial cells that surround the vascular component
food processes (pedicles) of podocytes
what type cell is a podocyte?
epithelial cell
3 things to remember about the kidney
there are vascular components (dzs due to BVs coming into kidney)
dzs that primarily injury the glomerulus (not necessarily the tubules)
injuries primarily to tubules and interstitium (don’t affect glomerulus)
with damage to the glomerulus what will you see on dipstick?
proteinuria
with a problem w/ the tubules what would you expect to see?
fluid or electrolyte management
wasting of sodium, glucose, amino acids
60-80% of everything that is filtered by the glomerulus is reabsorbed where?
proximal tubule
all resabsorptive functions of any of the tubules (proximal, loop of henle, distal, collecting duct) requires what?
energy (primarily glucose)
where is bicarbonate reabsorbed?
proximal tubules
what else is reabsorbed in the proximal tubule?
Na
glucose
phosphorus
where is carbonic anhydrase found?
proximal tubules
diuretic affect this
section of nephron where concentration of medullary space happens.
loop of henle
what happens in the descending part of the loop of Henle
water goes out, fluid becomes concentrated (1200)
what happens in the ascending loop of henle?
transport NaCl out
hypertonic area
sensitive to ischemic loss
what happens in the thick part of the ascending loop of henle?
Na, K, and 2 Cl are transported out
back to normal osmole concentration of body
where do loop diuretic works?
thick part of ascending loop of Henle
what does ADH do in the thick ascending limb?
ADH acts to cause fluid reabsorption
where do thiazide diuretic swork?
distal convoluted tubule
block Na/K co-transport system
where do you form free water because Na is moved out of luminal cells but the membrane is impermeable to water.
distal convoluted tubule
where does aldosterone have a significant effect and causes Na reabsoprtion and K and hydrogen secretion
cortical collecting duct
where do the potassium sensitive diuretics act?
cortical collecting duct
area where final acidification occurs. Na/K exchange mechanism. fine tuning of acid/base balance occurs.
medullary collecting duct
where does the formation of Tamm-Horsfall protein occur? (forms matrix of casts of urine)
distal tubule
pressure that is a result of plasma protein in blood
oncotic pressure
pressure determined by blood pressure
hydrostatic pressure
what is glomerular filtration a function of
surface area
permeability
hydrostatic/ oncotic pressures
what is creatinine production rate?
10-20 mg/kg/ 24 hours
how do you figure out 24 hour creatinine production?
15 mg/kg/24 hours x weight in kgs
an adequate 24 hour urine collection should have how much protein?
1 gram
what’s the most creatinine will increase in 24 hours?
2 points
what is the formulation for CC?
[(140-age) X LBW] / 72 X Scr (mg/dl)
what is LBW for females?
45.5 + (2.3 x each inch from 60 inches)
what is LBW for males?
50.0 + (2.3 x each inch from 60 inches)
a serum creatinine of -1.0 corresponds to what GFR?
100
a serum creatinine of -4.0 corresponds to what GFR?
25
a serum creatinine of -8.0 corresponds to what GFR?
12.5
when serum creatinine doubles, GFR decreases by what?
50%
why can plasma creatinine increase?
increased release from muscles
decreased proximal tubular secretion
analytical interference (lab erros)
what drugs cause decreased proximal tubular secretion
cimetidine
triamterene (diuretic)
trimethoprim
what is the better determinate for renal failure
creatinine
what is the normal BUN/ creatinine ratio
20:1
what can cause an increased Bun to creatinine ratio
effective volume depletion GI bleed early obstructive uropathy catabolic states/ sepesis increased protein intake steroids tetracycline
what can cause a decreased BUN/Cr ratio (<10:1)
Liver dz
low protein
rhabdomyolysis
what is urine production <50-100 mL/ 24 hours
anuria
what is urine production of 100-480 ml/24 hours
oliguria
what is urine output of >3 L/ 24 hours
polyuria
what is high output state?
0.5-1.0 Liters/hour
labs to get with kidney disease
CBC
CMP
urinalysis
urine eosinophils
best initial imaging in renal disease
US and doppler (renal blood flow)
gives anatomical features and function (secretion of isotopes)
isotopic renogram
what is the concern w/ gadolinium?
exacerbating renal failure
what does negative urinary sediment means?
water like
what does bland urinary sediment mean?
non-diagnostic
what does an active urinary sediment mean?
diagnostically suggestive
what does an angry urinary sediment mean?
diagnostic implications
where do dysmorphic rbcs come from?
injured glomeruli
how many WBCs per high powered field have some diagnostic significance
3-5 WBCs
if you see a red blood cell cast what does that indicate?
glomerulonephritis
what does a WBC cast indicate?
from kidney, they were in tubular fluid
pyelonephritis
tubular interstitial condition
what does a fatty cast indicate?
major lipid disorders
nephrotic syndrome
what will a polarized fatty cast look like?
looks like clovers
what does a granular cast indicate?
concentrated urine and low flow state
what crystals look like a coffin?
phosphate crystals
what HIV drug can produce stones and cause obstructive neuropathy
indinavir
most frequent cause of hematuria
urinary tract infection stones exercise, trauma endometriosis sickle cell polycystic kidney disease cancers BPH intrinsic glomerular dz
what is glomerular protineuria usually
albumin
when does orthrostatic proteinuria go away
at night
but will be >2.0 grams during the day
what can cause tubular proteinuria?
microglobulins
albumin
usually <1.5-2 grams a day
whey do you look at the retinas?
window to microvasculature
mild albunimuria is associated with what?
increased CV risk
what can hyperfiltration due to only having one kidney lead to?
focal glomerular necrosis
proteinuria can get worse
do you see dysmorphic RBCs with diabetic disease?
No usually of a vascular origin not an inflammatory origin
what can statins cause?
heme positivity on a UA
statins can lead to rhabdomyolysis
if you see a 3+ blood on urine but not RBC casts what is the cause?
breakdown of myoglobin
