Urinary System (8) Flashcards
components
- aorta
- renal artery
- kidney
- ureter
- bladder
- urethra
kidney structure
- renal capsule
- cortex
- medulla
- renal column of bertin (b/t medulla pyramids)
- renal papilla
- minor calices
- major calyx
- renal pelvis
- renal sinus (fat filled space)
- hilum for all tubes/ducts/nerves
renal capsule histology
two layers
1. outer = collagen + fibroblast
2. inner = collagen + myofibroblasts
myofibrils contractile and springy
nephron components
- renal corpuscle
- proximal convoluted tubule
- distal convoluted tubue
- loops of henle w/ thin and thick ascending + descending
basic unit of kidney
cortical labyrinth
has all the curly stuff aka renal corpuscle + both convoluted tubules + connecting tubule
medullary rays
all the straight stuff aka tubules/limbs + collecting duct
extend from base of pyramid to cortex
loops of henle
short loop and long loops
longer concentrate urine more than short
uriniferous tubule
nephron + collecting duct
kidney lobes
renal pyramid (medullary) + cortical arch + columns of bertin
kidney lobule
collecting duct + all nephrons that empty into it
corpuscle development
developing glomerulus w/ afferent and efferent tubes invaginates tubule
ends with visceral layer (of Bowman’s capsule) on glomerulus + parietal layer outer
corpuscle components
- afferent arteriole = blood into cap bed, larger
- efferent arteriole = blood away, smaller since less from filtering
- urinary space = filtrate diffuses into from cap bed, aka bowmans space
- glomerulus = tufts of fenestrated capillaries surrounded by bowmans capsule
filtration barrier
corpuscle
- podocytes (primary) extend pedicels (secondary) around glomerulus for large moles
- nephrin diaphragm b/t pedicels for small moles like proteins
podocytes form visceral layer of bowman capsule
congenital nephrotic syndrome
mutation in nephrin gene so leaky diaphragm
-massive proteinuria > edema
layer histology
-glomerulus
- endothelial @inside cap bed = glycocalyx + glycoproteins
- basement membrane = basal lamina
- parietal epithelial cells = simple squamous
intraglomerular mesangial cells
phagocytic
-resorbs basal lamina and crud
@ basement membrane/basal lamina b/t capillaries
alport’s syndrome
aka hereditary glomerulonephritis
-mutation in gene for type IV collagen in glomeruli
=renal leaking, hematuria, proteinuria, progressive renal failure
proximal convoluted tubules
ultrafiltrate pass from corpuscle into lumen of PCT via urinary pole
vascular pole at other end of bowmans capsule for blood
PCT histology
cloudy looking, acidophilic cytoplasm, low mitochondria
cuboidal cells + microvilli for brush border
loops of henle
PCT > thick descending limb of loop
so has same profile as PCT
thick ascending > DCT so same profile
thick = cuboidal VS thin = simple squamous
vasa recta
arteries with RBCs that look like they have bubbles
distal convoluted tubules
DCT
has clear lumen (more white space) and smaller cuboidal epi
-fewer microvilli
-more mitochondria
-ZO tight junctions
macula densa
modified seg of distal tubule for renin secretion via juxtaglomerular cells
chemoreceptor cells sensitive to sodium chloride so imp for reg blood pressure
juxtaglomerular cells
modified smooth muscle in tunica media of afferent arteriole
have granules of renin for BP regulation
jux. apparatus = macula densa + jux cells
blood pressure fall pathway
- in resp to low sodium: macula densa dilates afferent arterioles to inc flow in + instructs jux cells to release renin
- renin converts angiotensinogen to angiotensin 1 (mild vasoconstrictor to inc P)
- ACE converts it to angiotensin 2
- angiotensin 2 is potent vasoconstrictor, inc thirst, release aldosterone, release ADH, inhibit renin release, release prostaglandins so afferent stays dilated
connecting tubules
simple cuboidal epi with basement membrane + supporting tissue
multi connecting tubules enter into single collecting duct
collecting ducts
columnar epi
surrounded by renal interstitium with fibroblasts + macrophages + CT
renal papilla
20 ducts of bellini open into papilla of pyramid = area cribosa
covered by transitional epi
calices
funnel shaped lined by transitional epi + has smooth muscle layer
minor = urine from single pyramid
major = urine from up to 4 minors
ureter histology
star shaped lumen when empty with transitional epi
-lamina propria
-smooth muscle longitudinal inner and outer + circular for peristalsis
-adventitia
bladder layers
- mucosa = transitional epi + lamina propria
- muscularis = inner longitudinal + outer circular + outermost longitudinal
transitional have dome/umbrella surface cells
urothelium cells
@umbrella/dome cells for accomodation
have urothelial plaques + interplaque regions = impermeable barrier
also has hinge regions + fusiform vesicles make jagged contours when empty
male urethra
- prostatic @ prostate gland lined by transitional epi
- membranous @ perineal membrane lined by stratified columnar epi + pseudo columnar
- spongy @ penis lined by stratified columnar + patches of pseudo and stratified squamous non keratin
- glands of littre line urethra, mucous glands @ lamina propria
penile urethral glands
glands of littre and bulbourethral glands of cowper lubricate urethral lumen
nuclei of littre release mucous to clean urethra of urine prior to ejaculation
female urethra
transitional epi near neck of bladder > stratified squamous nonkeratin epi + patches pseudo columnar
numerous glands of littre
