L38 39 Urinary System Flashcards
Define components of a uriniferous tubule
uriniferous tubule is composed of a nephron and a collecting tubule
nephron is composed ot renal corpuse and tubule system
- corical nephrons (85)
- juxtamedullary nephrons (15)
renal corpuscle has a bowmans capsul, glomerulus and intraglomerular mesangial cells
Bowmans capsul components
basal lamina on exterior
pareital layer lining inside of capsul (simple squamous epithelium)
bowmans space
visceral layer of podocytes (a modified epithelial cell)
- wrap around the fenestrated capilaries
- have primary processes
- secondary processes (pedicles)
- filtration slits in between teh secondary processes
- filtration slits have a diaphragm
-know vascular pole and urinary pole
Filtration apparattus three main components
fenestrated endothelial cells are first barrier for blood (no diaphragmss)
- thick basal lamina from podocytes and glomerular endothelial cells
aka glomerular basement membrane (GBM)
-composed of Typ4 collegen, laminin, fibronectin, PG’s GAGs
-stain dark in H&E - filtration slit in diaphragm between pedicels
- composed of glycoproteins similar to diaphragm in most fenestrated caps
Goodpasture Syndrome
Autoimmune respose to collagen Type 4
affects GBM of renal corpuscle
urinary system symptoms -hematuria/proteinuria affects alveolar basement membrane too respitory system symptoms -short breath, cough, bloody sputum
-glomerulonephritis indicated by cellular cresent of macrophages, fibrin and proliferating cells
intraglomelular mesengial cells
- look at image on slide 15 for location
1. phagocytose large macromolecules trapped by basal lamina in filtration process
2. provides structural support for glomerulus
3. secretes interleukin 1 and platelet derived growth factor to wait in repair of glomerular injury
Derived from SMC precursors
Proximal Tubule
14mm in length 60microns in D
simple cuboidal ep with LONG MICROVILLI brush border
Endocytotic vesicles and high density of mitochondria
darker cytoplasm with H&E and STAR shaped lumen
basal processes with bundles of actin filaments may regulate fluid movement
proximal convoluted tubule (pars convoluta) 2/3 of length of descending thick limb of loop of henle (pars recta) 1/3 of length
Vitamin D deficiency
when we ingest vitamin D it is in an inactive form
transformations occur in the liver and prox tubule of kidney to produce active form
active form helps regulate plasma calcium levels
end stage chronic kidney diseases result in a reduced BONE DENSITY
thin limbs of henles loop
variable length 2mm for fortical nephrons and up to 10mm for juxtamedullary nephrons
15-20micon diameter
simple squamous epithelium
composed of descending and ascending limbs
distal tubule
14mm length 30-40micron D
simple cuboidal epithelium with VERY FEW short MICROVILLI (NO BRUSH BORDER)
light staining cytoplasm in H&E- ROUND LUMEN
ascending thick lim 2/3 of lenths , distal convoluted 1/3
juxtaglomerular apparatus
right nedt to glomerulus but on vascular pole (attached)
macula densa cells: distal tubule between pars recta and part convoluta
- near afferent ane efferent glomerular artiorioles
- tall narrow cuboidal cells which close together nuclei
juxtaglomerular cells: granular cells of the afferent glomerular arteriole
-modified SMC that contain granuals of renin
extraglomerular cells: similar to pericytes…unkown function
collecting tubule
OBVIOUS LATERAL PLASMA MEMBRANES
20mm in length 60micon diameter
simple squamous epithelium proximally
columnar epithelium distally
NOT PART OF NEPHRON-derived from different mesoderm structure
collecting tubules to collecting ducts to papillary ducts of bellini (BIG)
Kidney layers
capsule: DiCT
myofibroblast layer (fxn unkonwn)
cortex:
- medullary rays: collecting tubules and thick asencding and descending limbs of henles loop
- cortical labyrinth: renal corpuscles, prox conv tubules and distal conv tubules
- lobuleL medullary ray and surrounding labyrinth
medulla: renal pyramids, corical arches and cortical colums
MedullaL 6-12 medullary pyramids
-composed of collucting tubules
-thick descending and ascending limbs of henle
-separated by cortical colums of bertin
-cortical arch overlies base of renal pyramid
Renal Papilla: apex of pyramid, contains area cribrosa (20 pap ducts of bellini), empties into minor calyx
lobe: renal pyramid and associated cortical tissue at base and sides
NOTE: innder medulla has lower O2 level, decreased metabolism and less mitochondria than outer cortex
-dictates which biochemical path happens where
BLood supply
Medulla:
Renal artery, anterior and posterior divisions
Five segmental arteries (1 segment removeable)
6-15 lobar arteries
interlobar arteries
arcuate arteries
Cortex: arcuate arteries interlobar arteries afferent glomerular arterioles efferent glomerular arterioles
peritubular capillary network
-incudes vasa recta of arteriolae rectae and venae rectae in medulla
RBC formation
EPO stimulates bone marrow
EPO produced by peritubular capilary cells
chrinic kidney disease results in anemia
blood drainage of kidney
Cortex: stellate veins
interlubular veins
arcuate veins
medulla venae rectae arcuate veins interlobar veins renal veins inerior vena cava
Kidney lymphatics/innervation/interstitium
lymphatics
-superficial and deep lymph vessels follow larger arteries, form larger lymph vessels near the hilum, then ab aorta and vc nodes
inn
symp nerve fibers from renal plexus inn blood vessels and renal tubules, juxtaglomerular cells, intersitial cells and kid capsule
interstitium
-loose CT in cortex, contains fibroblasts and macrpphages while in medulla contains fibroblats macrophates and intersitial cells
resorbed water passes from nephrona nd collecting tubule into renal intersitium and thenblood supply
minor and major calyx and ureter
minor 6-12 per kidney -20 ducts of bellini into each majorL 3-4 -2-4 minor calyces empty into each -empty into renal pelvis BOTH trans epithelium
URETER Mucosa -trans epithelium (3-5 cells) -lamina propria of Di Fibroelastic CT -no SM or MM
Muscularis:
- inner long/outer circ SMC
- inner long, middle circular, outer long for distal 1/3
Adventitia
-fibroelastic CT taht blends with capsul of Kidney and urinary bladder wall
Flaps of mucosa hang over utretic orifice to prevent regurgitation of urine
Bladder
Mucosa: Transitional epithelium that FOLDS
- lamina propria of Di Fibroelastic CT
- CT with mucous glads near urethral orifice
- No SM or MM
Muscularis: (detrusor)
- thin inner and outer long smooth layers
- thick middle circular smoooth that forms internal urethral sphincter aroun internal orifice of urethra
Adventitia:
Di collagenous CT w/ elastic fibers
PM of epithelial cells has THICK regions called plaques which invaginate into the relaxed bladder
-appear as vesicles in TEM but lumen in cont with exterior
Urethra
Mucosa
- Trans Ep
- then squamous/psc/pathes of psc
- mess of highly variable ep
1. prostatic: trans
2. membranous: strat columnar
3. spongy/penile: strat columnar and PSC
LP
- CT with mucus secreting glands of littre for lube
muscularis: innter long a nd outer circular SMC - skeletal muscle outside to form external urethral sphincter where peirces perineum
Blood filtration
basal lamina is continous extracellular layer between two discontinous cell layers making the BL the primary filtration
- proteins less than 5kb pass free, larger and negatively charged molecules will NOT pass
- repelled by GAGs
Proximal Tubule
look at notes for distal tubule
renin angiotensin system
collecting tubule
perm to water and salts
- active transport of Na by Na K ATP pump
- passive diffusion of water through aquaporins (H2O channel)
- resorbtions back into blood supply of 65-70% of H2O na and 100% of proteins AA and glucose
