Renal - Exam 2 Flashcards
functions of kidney - 5
- excretion of wastes/foreign substances
- regulation of electrolyte balance
- regulation of acid-base balance
- regulation of fluid osmolality/volume
- production and secretion of hormones
3 hormones kidneys produce and secrete
Vit D3, erythropoetin, renin
nutcracker syndrome is where the..
LEFT renal vein becomes compressed between the SMA and AORTA
results of nutcracker syndrome - 3
- kidney enlargement
- venous HTN
- rupture of thin walled veins of collecting system (HEMATURIA)
urinary tract obstructions are caused by
many mechanisms
list 5 causes of urinary tract obstructions
- polycystic kidney
- kidney stones
- blood clot
- carcinoma
- endometriosis
___ is the outer portion of the kidney, houses the glomerulus (filtration) and is where the renal artery becomes the renal vein
cortex
____ is the pyramid shaped inner portion of the kidney which houses most of the nephron (maintenance of salt and water balance in blood)
medulla
____ is the functional filtering unit of the kidney
nephron
we have ___ million nephrons in each kidney, number naturally declines with age
1.2 million
each nephron filters…
a small amount of blood
5 parts of the nephron
- glomerulus (cortex - filtration)
- proximal tubule (cortex)
- loop of Henle (medulla - concentrates urine)
- distal tubule (cortex)
- collecting ducts (medulla)
the nephron works by:
- the glomerulus lets ____ and ____ pass but not ____ or ___
- filtered fluid passes through the tubule which sends minerals to blood and removes waste. the product is ____
the nephron works by:
- the glomerulus lets fluid and _waste pass but not cells or protein
- filtered fluid passes through the tubule which sends minerals to blood and removes waste. the product is urine
JGA is formed by ____ and ___
DCT and glomerular afferent arteriole
JGA regulates ___ and ____
BP and GFR
3 cell types in the JGA
- juxtaglomerular cells
- extraglomerular cells
- macula densa
juxtaglomerular cells are in the ___ and produce ____
afferent arteriole wall, produce renin
extraglomerular cells AKA
lacis cells
macula densa cells are in the ____
DCT
macula densa cells sense respond to ____ and…
INC NaCL, they vasodilate afferent arterioles and INC renal blood flow to maintain GFR
fx of glomerulus is
plasma filtration
____ brings blood into Bowmans capsule and goes out through the _____
AFFERENT brings blood in, EFFERENT out
the glomerulus contains a ____ ____
filtration barrier
___ and ____ cannot cross the barrier
cells and proteins
what 7 things are filtered in the glomerulus
- h20
- glucose
- electrolytes
- creatinine
- small peptides
- amino acids
- small chemicals
3 barriers to filtration in glomerulus
- endothelial cells
- GBM
- podocytes
endothelial cells have _____, small holes that allow plasma through but not protein/cells
fenestration
the GBM has a _____ that keeps ___ out
strong negative charge that keeps albumin out
the GBM is formed by
a matrix of proteins
___ is a disease that breaks down the GBM (loses neg charge and albumin is lost of urine, NOT normal)
DM
_____ like scleroderma causes changes in fenestration of endothelial cells
autoimmune diseases
podocytes are a cell unique to the
kidney
podocytes create a ____ formed by interdigitate interaction of adjacent podocytes
filtration slit
in minimal change disease ___ disappear
podocytes
mesangial cells are ____ in the filtration barrier of the glomerulus
support cells
net filtration pressure is ___ and favors…
12 mmHg and favors pushing plasma into filtration in bowman’s capsule
the ____ in the cortex is the major site of reabsorption
PCT
___ % Na, ___ % H2O, __ % bicarb, __ % of other electrolytes are reabsorbed in the PCT
60% Na, 70% H2O, 80% bicarb, 90% other electrolytes
type of cells in PCT
tubular epithelial cells
tubular epithelial cells have ___ and ___
brush border and mitochondria
the brush border
INC SA to touch as much filtrate as possible
the mitochonidria
provide energy for active transport of filtrate via transporter proteins
____ is death of the tubular epithelial cells which are susceptible to a lack of O2
ATN (acute tubular necrosis)
with dec blood vol, there is dec circulation to kidneys this cell dies first so you have problems with reabsorption
tubular epithelial cells
ATP independent processes - 3
symporters, channels, exchangers (depend on conc. gradient)
ATP dependent processes need
transporter proteins
the capacity of transporter proteins can be ___ and the function can be ____
capacity can be saturated, fx regulated
____, ____, ____ are absorbed in the PCT by transporter proteins (ATP dependent)
ions, glucose, AA
H2O is absorbed by ____ and ____
tight junction and water channel (aquaporin)
bicarb cant enter as an ion, must be in the form of
CO2 gas
bicarb is reabsorbed into the blood in the PCT by
sodium bicarb transporter, symporter
peptides are absorbed via
receptor mediated endocytosis (megalin/cubilin complex)
loop of henle aka
countercurrent multiplier
loop of henle fx is to establish a _____ state in the
hyperosmotic state in the medullary interstitial fluid
thin descending segment is
- H2O ____
- moderate permeability to ___ and ____
thin descending segment is
- H2O PERMEABLE
- moderate permeability to Na and urea
thin ascending segment is
- H2O ____
- ONLY ____ reabsorbed
thin ascending segment is
- H2O IMPERMEABLE
- ONLY Na reabsorbed
thick ascending segment is
- HIGHLY ____ permeable
- ___ and ____ IMPERMEABLE
thick ascending segment is
- HIGHLY Na, K, Cl permeable
- urea and H2O IMPERMEABLE
filtrate entering the nephron is _____ to blood plasma and interstitial fluid
isosmotic
water moves ____ the filtrate in the DESCENDING limb down its osmotic gradient which concentrates the fluid
OUT OF
filtrate reaches its highest conc at the
bend of the bloop (WATER CANT GET OUT)
Na and Cl are pumped out of the filtrate which ___ the interstitial osmolality
INC
filtrate is MOST DILUTE as it
leaves the nephron loop (100 most it is hypo osmotic to the interstitial fluid)
____ and ____ destroy the countercurrent multiplication system so that the kidney CANT reabsorb water
loop inhibitors and loop diuretics
the two functions of the DCT
electrolyte homeostasis and hemodynamic regulation
in the DCT, __ is reabsorbed (___ acts here)
Ca reabsorbed, PTH acts here
cells responsible for hemodynamic regulation
macula densa
macula densa release renin when
Na levels are low
___ is the action site for hormones
collecting duct
which hormones act in the collecting duct
aldosterone and ADH (vasopressin)
two types of cells in the collecting duct
intercalated and principal
intercalated cells have ____ reabsorption and ___ secretion
bicarb reabsorption and H secretion
principal cells/aldosterone regulate ___ absorption and ___ secretion
NaCl absorption and K secretion
the collecting duct leads to the
renal pelvis
______ is a steroid hormone
aldosterone
aldosterone is produced in the
adrenal gland
antagonist to aldosterone
sprionolactone
aldosterone acts on ____ to…
prinicpal cells to INC reabsorption of Na and secretion of K (leads to H2O retention and INC BP)
____ disease is a lack of aldosterone, which INC K and DEC Na
addisons
ADH/vasopression is made of
9 AA
ADH is produced in the
hypothalamus (stored in the posterior pituitary)
ADH is released in response to
INC plasma osmolality
if you are dehydrated, ADH is released which acts on the..
collecting duct to produce aquaporin receptors so water is reabsorbed, urine is low in volume and concentrated
with DI (diabetes insidious) you lack
ADH
with DI you have an abnormally large amount of
urine that is insidious (water not reabsorbing in collecting duct)
with Central DI there is damage to the ____ which causes ____
damage to the hypothalamus/pituitary which causes disruption in the production, storage, and release of ADH
nephrogenic DI is when the
kidneys DONT RESPOND normally to vasopressin
3 types of regulation of RBF (renal blood flow)
- autoregulation
- neural regulation
- hormonal regulation
autoregulation maintains a ____ RBF and GFR through a ___ mechanism
CONSTANT RBF and GFR through a myogenic mechanism (smooth muscle)
if there is an increase in arteriole pressure the arterioles ___
relax
neural regulation produces ___ and ___ GFR and RBF
vasoconstriction and DEC GFR/RBF
the afferent and efferent arterioles are innervated by
sympathetic non-adrenergic nerve
____ regulation of RBF takes place in an emergency volume depletion
neural
the major hormonal regulation of RGF
RAAS
the natural antagonizing agents of RAAS
natriuretic peptides
RAAS is activate by __ BP and ___ in DCT, releases
DEC BP and NaCl in DCT, releases RENIN
renin converts ___ to ____
angotensinogen to AT1
____ turns AT1 to AT2
ACE
___ is the active molecule which causes VASOCONSTRICTION and INC BP
AT2
RAAS causes
- INC BP
- vasoconstriction
- INC NaCl
- water follows
- ALDOSTERONE secretion
- INC perfusion of JGA
where are natriuretic peptides synthesized and secreted
heart cells
natriuretic peptides INHIBIT ___ and ____ secretion
aldosterone, renin
natriuretic peptides ____ afferent and efferent arterioles, dec blood vol, dec CO, dec BP
vasodilate
_____ of the kidney are mutations in critical proteins that produce BRUSH border cells in PCT
hereditary disorders
example of hereditary disorder of kidney
polycystic kindney disorder (mutation in proteins that form brush border cells)
6 acquired diseases of the kidney
- inflammation (glomerulonephritis)
- diabetes (diabetic nephropathy)
- AKI (ischemic)
- chronic kidney disease (HTN)
- kidney stones
- drugs and toxins
diabetic nephropathy is a chronic kidney disease characterized by these 4 things
- INC proteinuria
- DEC GFR
- HTN (activates RAAS - A2 constricts efferent arteriole, INC glomerular capillary pressure)
- INC risk/VC, morbidity/mortality
normal BG
70-130
diabetic BG
over 200
early stage diabetic nephropathy
INC GFR, reversible albuminuria
advanced diabetic nephropathy
GBM expansion, proliferation and hypertrophy
with diabetic nephropathy there is a thickening of the GBM due to
elevated cell proliferation mediators (PDGF, TGF-B, VEGF)
4 pathology signs of diabetic nephropathy
- expansion of mesangial matrix
- thickening of GBM
- arteriosclerosis
- tubulointerstitial fibrosis (proteins leaked into PCT initiate inflammatory response with leads to formation of fibroblasts)
AKI is the sudden decline in kidney fx with a ___ GFR and ___ Cut and BUN
DEC GFR, INC Crt and BUN
AKI is associated with oliguria (___) and anuria (____)
oliguria - less than 400 ml/day of urine
anuria - less that 50 ml/day of urine
pre-renal AKI has
inadequate CO
intrarenal has ___ and ____
ATN (most common cause of infrarenal AKI) and acute interstitial necrosis
post renal is the
obstruction of urinary tract
patho of ATN
- ischemia leads to cell injury
- loss of brush border in PCT cells
- loss of polarity and integrity of tight junctions
- relocation of Na/K/ATPase pumps and interns to the apical membrane
- cell death (apoptosis and necrosis)
- cast formation and obstruction of tubular lumen
ATN is ____ if caught early
reversible (PCT cells are regenerative)
causes of ATN
hypoperfusion, ischemia, nephrotoxic antiRX, xray media, cisplatin
renal filtration regulation is composed of ___ and ___
GFR and RBF
___ is constant even with BP change
RBF
GFR = ___ per min and ___ per day
120 mL/min, 180 L/day
RBF = ____ mL/blood/min and ____ mL/plasma/min
1000-1200 mL/blood/min, and 600-700 mL/plasma/min
