excretion 1 Flashcards
functions of kidney
maintain blood volume- remove excess
blood pressure- secrete renin
metabolism- gluconeogenisis, erythropoietin, vit D
detoxify
layers of glomerular membrane
endothelial layer
basement membrane
capsular layer
endothelial layer
highly porous allows for easy filtration
single layer
basement membrane
made up of glycoprotein, no cells
negative charge = can repel
capsular layer
podocytes
increase filtration capacity
cortical nephrons
mostly in cortex
85%
JX nephrons
deeper loop of henle- deep into renal pyramids
forms concentrated urine
intra-mesangial cells
provide support for glomeruli
secrete substance similar to BM
extra-mesangial cells
between afferent and efferent arterioles
respond to hormonal substances
regulate blood flow
both types of mesangial cells are
phagocytic in nature
factors that effect GFR
capillary pressure
osmotic colloidal pressure
tubular pressure
capillary permeability
constriction of efferent
increase resistance of outflow
increase glomerular pressure
constriction of afferent
reduction in blood flow
reduction in filtration pressure
reduce GFR
afferent and efferent are innervated by the ______ system
sympathetic nervous system
which ions are completely reabsorbed?
Na+
Cl-
K+
HCO3-
what do Na+ anti porters do?
they reabsorb Na+ and secrete H+
PCT cells produce H+ &
release bicarbonate ion into peritubular capillaries
Na+ symporter
help reabsorb materials from tubular filtrate
facilitated diffusion & passive transport
neither use energy
primary active transport
first step requires ATP
secondary active transport
second step requires ATP
cotransport
1 is transported, other tags along
counter transport
1 absorbed, 1 secreted
secretion in PCT
secrete H+
secrete organic compounds- penicillin, aspirin, morphine
thick descending limb
highly permeable to water
moderately permeable to urea, Na, others
thick ascending limb
impermeable to H2O
symporter for reabsorption of Na+, Cl, K
DCT
impermeable to water
removal of Na and Cl
how is Ca+ actively reabsorbed?
under the influence of parathyroid hormone and vit D
transport mechanism
each supporter has an upper limit for how fast it can work
maximum amount of substance that these transport systems can reabsorb per unit time
TM for glucose
375 mg/min
why glucose in urine of diabetic?
renal threshold is 180 mg/dl
ADH & aldosterone w/ maintaining blood vol
water permeability
insertion of aquaporin-2 channels
water reabsorption
main purpose is to increase water reabsorption
