urinary system Flashcards
organs of the urinary system
kidney. bladder. ureter . urthra
the kidneys filter about __ of cardiac output
20%
125 ml/min of blood are filtered by the kidneys but only __% goes to bladder
1%
podocytes
pedicels/foot processes
components of the filtration barrier
Filtration slits
Heparan sulfate proteoglycan
Type IV collagen
Podocalyxin
mesangial cells
take up glomerular basal lamina material for turnover and phagocytise Ig trapped in basal lamina .
contract and regulate glomerular filtration by controlling blood flow through capillaries
cytoskeletal contractile proteins
modify blood flow through glomerular capillaries by contracting mesangial cells
angiotensin 2
bind to receptor to stimulate mesangial cells
Acts directly upon blood vessels to increase vasoconstriction and arterial pressure.
Stimulates secretion of aldosterone from the adrenal cortex.
Aldosterone
Aldosterone acts upon the kidney to improve retention of sodium
endothelin
protein: vasoconstriction of efferent and afferent arterioles
Podocalyxin
Podocalyxin in maintaining foot processes
proximal tubule features
simple cuboidal
apical tubulovesicles
basally locatated mitochondria
proximal tubule function
microvilli absorb water sodium , glucose, and a.a.
tubulovesicles capture peptides for degradation in lysosomes
megalin
protein that binds peptides in the proximal tubules
describe main action that happens in the loop of henle
sodium is actively transported out og ascending loop and establishes a concentration gradient in the interstitium
High osmolarity will cause?
High osmolarity DOES cause water to leave collecting ducts, but only when collecting ducts are made permeable to water
dark and light cells in the collecting duct
Light (principal) cells have single cilium
Dark (intercalated) Cells have many apical folds in the plasma membrane and they transport bicarbonate or H+.. controlling pH
__ + __ = Juxtaglomerular apparatus
The macula densa + juxtaglomerular cells = Juxtaglomerular apparatus
ADH
alters the function and distribution of aquaporin 2 which adjust the permeability to H2O in collecting ducts
JG cells are activated by __ and release __
macula densa
renin
macula cells
monitor sodium and Cl levels
renin is secrreted when
Na and Cl levels drop
Erythropoietin is produced by
peritubular firbroblast of the kidney
Erythropoietin
stimulate RBC production in the bone marrow
polycystic disease
Characterized by outgrowths from normal tubules that enlarge into huge, fluid-filled cysts
what can cause cyst on tubules
missing or abnormal cilia
uteric buds stimulate
condensation of the metenephric mesenchymal cells that differentiate into hollow epithelial structures that form bowmanns capsule and tubules
