Histology

Question 1

Stroma

Answer 1

thin capsule of collagen
-reticular fibers
-mesangial cells
very little of it in a functional kidney

Question 2

Parenchyma

Answer 2

epithelial cells arranged into tubules that drain into renal pelvis (expansion of ureter that sits in the renal sinus)

Question 3

Bowman’s capsule

Answer 3

double walled epithelium
Parietal=squamous outer wall
Visceral= podocytes

Question 4

cells w/in the renal corpuscle

Answer 4

endothelial cells of capillary 
mesangial cells (structural elements)
Podocytes (of visceral bowman's) 
squamous cells of parietal epithelium

Question 5

Glomerular filtration barrier

Answer 5

large fenestrations in endothelial cells

epithelial podocytes interdigitate to form filtration slits

Question 6

glomerular basement membrane

Answer 6

produced by endothelial cells and podocytes

• fuse to form trilaminar structure
• *primary barrier to filtration
• fenestrated
• rich in heparin sulfate, chondroitin sulfate, hylauronic acid, dermatan sulfate, and Type IV collagen

Lamina rara intima= capillary side
lamina densa= middle layer
lamina rara externa=tubular side

Question 7

size determinants of filtration

Answer 7

molecules 69000 do not pass(albumin, or other proteins-unless via reptation)

Question 8

charge determinants of filtration

Answer 8

due mostly to heparin sulfate
cations can pass more readily
plasma proteins can’t

Question 9

PCT

Answer 9

found in cortex
resorbs 70-80% of filtrate
cuboidal cells with dense microvilli and abundant mito (appear very pink with stuff in the lumen)
in EM there are long mito on the apical surface
*basolateral interdigitations (inc SA)

Question 10

PST

Answer 10

found in cortex and medulla
resorbs glomerular filtrate
similar to PCT, just few microvilli and infoldings
*runs in medullary ray from cortex to medulla and narrow at loop of henle

Question 11

LOH

Answer 11

in medulla
establishes hypertonic interstitium
countercurrent multiplier

simple squamous epi

Question 12

DST

Answer 12

continuous with ascending LOH, impermeable to water
cuboidal epithelium with basolateral digidations
round smooth lumen with apical nuclei
basal mito
pale staining

Question 13

DCT

Answer 13

resorbs salt
simple cuboidal with BL interdigitations
pale staining, goes back to the glomerulus of origin

Question 14

JG apparatus

Answer 14

JG cells (of afferent artery)+ macula densa (of DCT)+mesangial cells

monitor salt and blood pressure
—>release renin

Question 15

Collecting Ducts

Answer 15

cortical portion: receives urine from several nephrons, ducts run in center medullary ray toward medulla
Cuboidal—>become columnar (lumen increases in size distally)
Medullary portion:
tall cuboidal—>columnar
form large papillary ducts which open at area cribrosa of papilla

Question 16

Renal interstitium

Answer 16

surrounds collecting ducts
Type I cells: VDs (PGs, arachidonic acid )- control glomerular blood flow
Type II: phagocytes
Type II: ?

Question 17

Medullary rays (contents of)

Answer 17

LOH
some PST and DSTs
central collecting ducts

Question 18

Renal columns (contents of)

Answer 18

extensions of cortex into medulla 
Renal corpuscles, 
PCT
DCT
LOH
PST
DST
Central collecting ducts

Question 19

Renal lobule

Answer 19

medullary ray+labrynth
renal corpuscles
PCT and DCT

bordered by interlobar aa. which supply corpuscles

lose 1 lobular a—>lose 1/2 of each adjacent lobule

Question 20

renal vascular supply progression

Answer 20

aorta
renal a
segmental 
interlobar (b/w pyramids)
arcuate 
interlobar (from arcuate to capsule)
afferent arterioles 
glomerulus 
efferent arterioles 
vasa recta (in renal columns with collecting ducts) 
or 
peritubular capillaries (DCT and PCT)  
arcuate

Question 21

transitional epithelium

Answer 21

stratified epithelium
surface cells (umbrella or dome) stretch and flatten
connected with tight junctions

at renal calyx

Question 22

Ureter

Answer 22

stellate lumen
transition epithelium
Muscular layers
surrounded by serosa (peritonealized)

Question 23

Bladder

Answer 23

transitional epithelium
very thick muscular wall (detrusor)
intermural ureter
dome covered by peritoneum

Question 24

urethra

Answer 24

stellate lumen, highly folded,
high in elastin
changes to pseudostratified
strat squam at orifice

female has a venous plexus

Question 25

light cells

Answer 25

release water from tubue thru aquaporins

Question 26

dark cells

Answer 26

intercalated cells
alpha—>acid
Beta—> base