lecture 21/22 Flashcards
kidney, bladder
what is included in the urinary system?
- kidney
- ureters
- urinary bladder
- urethra
function of the urinary system
- excretion of waste pridcuts of metabolism
- regualtion of total body water
- regulation of electrolytes
- endocrine secretion of renin and erythropoietin
the renal corpuscle consists of _____________
a double wall of epithelial cells encoling the glomerular tuft of capillaries
what makes up the parietal layer?
squamous cells, BM, and reticular fibers
what makes up the visceral layer?
podocytes which is continuous with the parietal layer at the vascular pole and interdigitates around capillaries
what is found at the vascular pole of the renal corpsucle?
afferent arteriole enters and divided into 5 or more capillaries and the efferent arteriole leaves the structure
the _____ begins at the urinary pole
PCT
role of mesangial cells
- implicated in phagocytosis of particles, germs, and BM
- structural support of capillaries
- produce cytokines
capillaries in the kideny are _____
fenestrated with diaphrams
does the PCT have a brush border, what does it absorb, and what does it secrete?
- yes
- most proteins, glucose, Na, Cl, Ca, fluids
- secretes creatinine into the lumen
the thin descending limb is permeable to what?
water
does the DCT have a brush border, what does it absorb, and what does it secrete?
- very few
- Na, bicarbonate
- K, H
- site of aldosterone action
what does parathyroid hormone do?
increases the concentration of calcium in the blood by acting on parathyroid hormone 1 receptor
stimulates transcellular ca2+ absorption in renal distal convoluted tubules
how is calcitonin produced?
by parafollicular cells of the thryroid gland
functions of calcitonin
lower blood Ca2+ level in 4 ways:
* inhibit Ca2+ absorption by the intestine
* inhibit osteoclast activity in bones
* stimulate osteoblastic activity in bones
* inhibit renal tubular cell reabsorption of Ca2+, allowing it to be excreted
site of antidiuretic hormone (vasopressin)
collecting duct of bellini
what is the function of antidiuretic hormone?
make the collecting ducts permeable to H2O and thus water is retained
describe the juxtaglomerular apparatus
- juxtaglomerular cells: modified SM cells with secretory granules (renin, which converts angiotensinogen into angiotensin I)
- macula densa: modified DCT cells that detects the sodium concentration of the fluid in the tubule. cells are involed in the production of NO and otehr factors
- extraglomerular messangial cells:
role of angiotenin II
stimulate contraction of arterioles and increase blood pressure and stimulate production of aldosterone
what type of epithelium is found in the area cribrosa?
transitional epithelium
what are capilalries in the medulla called?
vasa recta
describe the renal blood supply
- renal artery and vein
- interlobar artery and vein
- arcutae artery and vein
- lobular artery and vein
- afferent arteriole goes into renal corpuscle
- efferent goes out
- peritubular capillaries
- stellate vein
- lobular veins
what is the role/function of erythropoietin?
- is a glycoprotein that promotes the proliferation and differentiation of erythrocyte precursors
where iserythropietin produced?
major site is kidney (in peritubular cells) but main extra-renal site is liver
normally the collecting duct is ___________ to water
impermeable
there is a high concentration of ____ in the medulla
Na+
what are the different cells seen in transitional epithelium?
- basal columnar cells
- middle poligonal cells
- superficial facet cells (dome cells)
