drug induced pathologies with kidney papilli
papilli are at the apex of the renal pyramids
cause necrosis and then they get blocked and urine can’t get out
what does a nephron consist of
glomerulus and collecting ducts and tubules
which type of nephrons have loop of henle?
juxtamedullary nephrons (not cortical)
efferent tubules
take blood away from glomerulus
what did pericapillary system/vasa recta come from?
efferent tubules
what are afferent and efferent arterioles sensitive to?
afferent: epinephrine
- constriction of afferent arteriole leads to decreased filtration (GFR decreases)
efferent: angiotensin-2
- constriction of efferent leads to increased pressure in glomerulus
hemorrhage leads to what in kidney
glomerulus shuts down (increased EPI constricts afferent arteriole) and GFR decreases to conserve fluids
what does macula densa do?
senses sodium potassium and it is at the end of the tubule before the collecting duct
renal clearance
amount of plasma that gets completely cleared
if substance is completely removed from plasma while passing through the kidneys, then clearance equals plasma flow.
most common cause of hyperosmolarity
dehydration
hyperosmolarity results in
hypothalamus releases ADH and increases thirst
low blood volume results in
baroreceptors (sympathetic NS) and macula densa activate sympathetic NS and release renin from JGA (volume regulation)
how much sodium goes back into the blood in the first two mm of proximal tubule and how?
how much in thick ascending loop of henle?
distal tubule?
67% (2/3) glucose, AAs, PO4 cotransporter and via Na/H exchange.
25% Na K Cl tritransporter
8% Na-Cl cotransporter
what is reabsorbed in proximal tubule?
67% Na and H2O
all glucose, HCO3, and amino acids
How much K is reabsorbed in proximal tubule?
distal loop of Henle
distal tubule
67% with Na and H2O
20% via Na K Cl tritransporter
either reabsorbed or secreted depending on dietary intake of K
What is interesting about K excretion in distal tubule?
if hyperkalemia, nephron can regulate and can pump K from blood to urine in distal tubule
- will see excess K in urine if hyperkalemic
what part of the nephron is water impermeable and generates the osmotic gradient?
Loop of Henle
what is job of macula densa?
Low GFR =
what is response to low GFR?
sense Na and Cl levels
increased Na/Cl
increase filtration rate by angiotenin 2 and constriction of efferent arteriole
what makes angiotensinogen?
liver
what converts angiotensinogen to angiotensin 1?
renin
ACE enzyme comes from where and what does it do?
Comes from lungs and converts angiotensin 1 to angiotensin 2.
what are 2 actions of angiotensin 2?
constricts efferent arterioles and increases GFR
promotes release of aldosterone from adrenal cortex (zona glomerulosa)
what does aldosterone do?
acts on distal tubules and forces reabsorption of Na and H2O and excrete K
aldosterone affect
Na increases and K decreases in blood
oxidative deamination
reductive amination
amino acid to alpha keto acid (removing N)
alpha keto acid to amino acid form (adding N)
what are ALT and AST enzymes dependent on?
vit B6
what do transamination reactions do?
removes amino group from amino acid, leaving behind it’s alpha keto acid
free amino group is transferred to a waiting alpha keto acid to form a new amino acid
urea cycle occurs where?
what does it do?
liver
gets rid of free CO2 and NH4
what happens if there is excess CO2 and NH4?
toxic encephalopathy
what part of urea cycle happens in mitochondria?
what part happens in the cytosol?
mitochondria: induction phase, ornithine is made with carbamoyl phosphate synthase, NH4 and CO2 and pumped out as citruline.
what enzyme hides CO2 and HH4 in mitochondria during urea cycle?
carbamoyl phosphate synthase phosphorylates N and C groups and puts them in a package that can encounter ornithine.
ornithine decarboxylase dephospharylates N and C onto ornithine
What happens to citruline when it gets outside of mitochondria in the urea cycle?
goes through many transamination reactions until it forms arginine
what does arginine do when it is acted on by arginase?
urea is made with left over portion of NH4 and CO2
what is happening in cytosol portion of urea cycle?
citruline undergoes various transamination reactions to form urea and ornithine residue restarts the whole cycle
backdoor for N residues?
amino shuttle that doesn’t use urea
oxidative deamination takes off N group and it is shuttled out of kidney with glutamine and then it finds H ions in urine and you pee out ammonia
acute glomerulonephritis is caused by what?
strep
derm, ortho joint, kidney/heart symptoms can happen after non-treated strep and this points towards post-strep glomerulonephritis
IgA nephropathy/Berger’s
increased IgA in response to viruses, bacteria (GI and lungs)
end up with hematuria, proteinuria, and chronic glomerulnephritis due to too much IgA
Henoch Schonlein Purpura
in children
respiratory illness prodrome, high IgA = sore joints, get leaky kidney, and get purpura
Goodpasture’s
rapid GN with auto-antibodies to basement membrane
young men who smoke
nephrotic syndrome
proteinuria, edema, hypoalbuminemia, hyperlipidemia, lipiduria
foamy urine
pyelonephritis
infection in kidneys (renal pelvis)
ascending fecal flora due to blockage (pregnancy, BPH)
medical emergency
hydronephrosis
swollen ureter or renal pelvis due to obstruction (stone)
what type of stones show up on X-ray?
Ca oxalate
uric acid calculi is secondary to?
gout
cystitis vs interstitial cystitis?
cystitis due to local flora (e. coli)
interstitial cycstitis: autoimmune attack on inner lining of bladder (punctate hemorrhages)
adenocarinoma/hypernephroma
painless hematuria
cigarette smokers
Wilm’s Tumor
common primary renal tumor in kids
large abdominal mass, painless hematuria
what do kidneys secrete?
EPO to increase RBC production in bone marrow
What do kindeys do?
filter blood secrete EPO volume regulation vit D activation gluconeogenesis in starving state
where are the kidneys located?
in retroperitoneal space
- deep to 12th rib
- r is lower due to liver
blood supply to kidney
aorta -> renal artery ->
what do kidneys secrete?
EPO to increase RBC production in bone marrow
What do kindeys do?
filter blood secrete EPO volume regulation vit D activation gluconeogenesis in starving state
where are the kidneys located?
in retroperitoneal space
- deep to 12th rib
- r is lower due to liver
blood supply to kidney
aorta -> renal artery -> segmental -> interlobar -> arcuate -> interlobar -> affarent -> efferent -> vasa recta -> renal vein goes into inferior vena cava
innervation of kidney
sympathetic via splenic n
what does kidney arise from?
mesoderm -> urogenital ridge -> ovaries and tests and nephrogenic cord -> holonephros -> pronephros, metanrphros, mesonephros
what do the pronephros, metanephros, and mesonephros turn into?
pronephros: regress
mesonephros: wolfian duct -> bladder and vas deferens, seminal vessicles, ejaculatory duct, epididmis
metanephros: from mesonephros: renal ureters, pelvis, calyces, collecting ducts
what forms the renal pelvis, calyces, collecting ducts?
metanephros via uretic bud
what gives rise to ovaries?
malarian duct via mesoderm and urogenital ridge
what gives rise to testes?
wolfian duct via mesonephros
what is blood glucose measure for diabetics?
over 160-200g/dL
what does collecting duct do?
ADH released from post pit to conserve water by increasing aquaporins
H2O reabsorption to concentrate urine
What hormone is released in distal convoluted tubule?
PTH reabsorbs Ca from filtrate into blood
What hormone is released into proximal convoluted tubule?
PTH secretes phosphate into filtrate = secretion
capillary endothelium
basement membrane
slit diaphragm in basement membrane
- fenestrated so that only certain sizes can get through
- charged heparin sulfate groups inhibit large molecules/proteins
- podocyte feet last catch
