Histology - Cole Flashcards
describe pathway of blood flow from renal artery on
renal a. –> segmental (lobar) a. –> interlobar a. –> arcuate a.
what gives off the structures that makes the glomerulus?
interlobular artery
what does the renal corpuscle do?
filters fluid from blood
what does the tubular portion do?
modifies filtrate into urine
what surrounds the juxtamedullary nephron?
vasa recta
what makes up the uriniferous tubule?
nephron
collecting tube/duct
what makes up the renal tubule?
PCT, loop of Henle, DCT which empties into the CT
what makes up the renal corpuscle?
Bowman’s capsule (visceral and parietal layers)
tufts of fenestrated capillaries - glomerulus
what layer of Bowman’s capsule is lined by podocytes?
what is the parietal layer made of?
visceral layer
simple squamous epithelium
what makes up the glomerulus?
podocytes, fenestrated endothelial cells, mesangial cells
what makes up the JG apparatus?
afferent and efferent arterioles
Macula densa
Extraglomerular mesangial cells
JG cells
what are the functions of the mesangial cells?
contractile - reduce/inc. blood flow through caps
phagocytic (reabsorption)
Secretory - PGs and and endothelins
supportive - where visceral layer is absent (modified smooth m.)
CPSS
describe the glomerular capillaries
what are they permeable to?
what are they a barrier to?
fenestrated, large pores not covered by a diaphragm
water, glucose, urea, small proteins
formed elements in blood and large macromolecules
what does the basal lamina contain?
type 4 collagen
laminin
fibronectin
(-) charged proteoglycans
what does each pedical have?
glycocalyx of negatively-charged podocalyxin
what are the pedicles separated by?
filtration slits and covered by slit diaphragm
what does nephrin do?
retards passage of molecules through fenestrations and basal lamina
mutations in nephrin gene lead to what?
congenital nephrotic syndrome
what are large molecules trapped by?
what stops negatively charged molecules?
basal lamina
basal lamina and podocytes
what kind of epithelium in PCT?
cuboidal/low columnar
microvilli w/brush border
function of PCT?
reabsorption of glucose, a.a., vitamins, Na, Cl, H20
function of loop of Henle?
form hypertonic urine by establishing osmotic gradient in hte interstitial fluid of medulla
where is the thin ascending loop found?
what kind of epithelial of entire loop?
Juxtamedullary nephrons only
squamous
what is the descending loop of Henle permeable to?
water and salt
as filtrate passes deeper, water is lost making it hypertonic
what does the ascending loop have?
what is it impermeable to?
what does it do?
Na/K/Cl Pump (symporter)
water
makes filtrate isotonic or even hypotonic
what kind of epithelium in DCT?
low cuboidal
what do Principal cells do?
intercalated cells?
reabsorb Na, secrete K
secrete H+ and HCO3-
what is the macula densa sensitive to?
what does it regulate via what mechanism?
NaCl
GFR by constricting afferent arteriole through Renin
what does decreased blood volume stimulate?
detection by macula densa and release of Renin by JG cells
AGII causes aldosterone to be secreted by suprarenal glands and reabsorption of Na and water by DCT, CT, and CD
what does aldosterone cause pumping of?
H and K ions into the lumen
what does ANF do?
what secretes it?
increases Na and water EXCRETION
opposes aldosterone, inhibits ADH release
atrial myocytes
what is urodilatin secreted by?
what does it do?
DCT and CD cells
inhibits NaCl and water reabsorption by medullary part and collecting ducts
name flow from DCT out to ureter
CTs –> CDs –> papilla –> minor calyx –> major calyx –> renal pelvis –> ureter
what releases ADH?
what does it do?
neurohypohysis (posterior pituitary)
reabsorb water from collecting ducts
describe the characteristics of urothelium
stratified
umbrella cells lined by desmosomes and tight junctions
forms osmotic barrier
what is the function of aldosterone?
what stimulates it?
reabsorption of NaCl in ascending loop of Henle, DCT, prinipal cells of CTs
increase in plasma [ ] of AgII and K+
what endocrine products does the kidney make?
EPO, Vitamin D, renin, PGs
what makes up the male urethra?
what kind of epithelium?
prostatic –> membranous –> penile
transitional –> pseudostratified/stratified columnar
what epithelium makes up the female urethra?
pseudostratified columnar to stratified squamous to moderately keratinized stratified squamous
what does the female urethra consist of?
inner smooth m. layer surrounded by external striated m. layer
what are the functions of the urinary system?
REEC
regulation, elimination, endocrine, conservation
