30 terms

Histo - Urinary

SGU Histo Urinary
kidney development
glomerulus invaginates renal tubule -> bowman's capsule
bowman space
receives filtrate
urinary pole
bowman's space cont w/ PCT, form filtrate through hydrostatic P
assoc w/ each renal corpuscle, vascular pole, 3 parts: 1) macula densa, 2) extraglomular mesangial cells, 3) JG cells, gap junctions betw the types
macula densa
distal tubule betw arterioles, inc cell #, reg renin secr by sensing dec NaCl
extraglomular mesangial / Lacis cells
betw macula densa + JG, may have granules, may be support cells affect by Angiotensin II
JG cells
mod smooth mm of afferent (and some efferent) glomerulus arterioles, sense Bp changes -> endocrine secretory cells for renin -> liver secretes angiotensin, large PAS-staining vesicles
makes liver secrete angiotensin
Angiotensin II
formed from Angiotensin I via ACE = angiotensin converting enzyme/angiotensinase, in endoth lung alveoli, stim Aldosterone synth in zona glomerulosa, vasoconstricter
Angiotensin III
formed by choroid plexus capps, stim Aldosterone synth, but weakly vasoconstrict like a poor-man's Angiotensin II
intraglomular mesangial cells
CT of glomerulus, analg to pericytes, cov area not cov by podocytes, actin microfils, Angiotensin I receptors, some are phagocytes, secr GFs + mediators of inflamm renal disease
epith cells of visc layer of renal corpuscle, long procs w/ sec pedicle procs that are the only part that touch the GBM
interdigitating foot procs of podocytes (sec procs) that contain lots of actin fils, space betw = filtration slits, makes the GBM
glomerular basement memb, thick and stained w/ PAS, bl-urine barrier that is fusion of two basal laminae: podocyte + endothelial cell laminae, has 3 parts: 1)podocyte lamina rara, 2) fused lamina densa, 3) endoth lamina rara
simple cuboidal epith, very eosinophilic, brush border, very large cells, 80% of filtrate resorbed is returned to circ (Glc, AAs, prots, vits), secretes H+, HCO3-, organic HA/Bs, penicillins, etc, have smooth SER w/ CytP450 for detox => lipofuscin bodies show up w/age
Loop of Henle
thick desc seg -> thin desc seg w/ simple squamous epith -> thin asc -> thick asc w/ simple cuboidal epith -> transition to DCT at macula densa
in cortical labyrinth, 1/3 as long as PCT, forms macula densa, less eosinophilic than PCT, no obvious brush border like PCT, smaller diam than PCT, more nuclei than PCT, func as Na+ sensor, stim by Aldosterone, resorb HCO3-/secr H+ (pH bal), conv ammonia to ammonium ion, target tissue for diuretecs + natriuretic factors to inhib Na+ reabsorb => dec Bp
stim Na+ reabs + K+ secretion in DCT
medullary ray
middle part of cortical/renal lobule, group of straight tubes that lead to collecting ducts
collecting duct
consist of light + dark cells, light = most comm, imperm to ions, ADH sens aquaporins (=> allow H2O absorb w/ osmotic grad, allows urea to exit), dark = dec in number toward medulla, secrete H+ into urine
interstitial cells
kidney parenchyma CT, w/ fibroblast-like + macrophage-like cells
vasa recta
counter current exchange sys, fenest capps, passive mov of ions + H2O, Desc: H2O moves out + solutes move in, Tip: 1M [urea], Asc: H2O moves in, salt moves out => osmotic grad drives flow of H2O and no E is used
stellate shape, no musc mucosa, musc externa (inner + outer longtid + middle circ, note the reverse order)
has 3 muscular layers, very transitional epith w/ apical plaques
Kidney natriurietc peptide, dec Bp (remove Na+ + H2O vs ADH/vasopressin, and R-AgT sys, works w/ atrial + brain natriuretic factors
erythropoetin / EPO
stim BM erythrocyte synth, in renal cortex interstitium, imp for athlete doping, kidney failure, or sclerotic defects
Pro VitD / Calcitriol
steroid essent for Ca2+ bal
transitional epithelium
urinary epith: imperm to salts + H2O, ability to become thinner + flatten, irreg apical surface w/ deep clefts
male urethra
prostatic (trans epith), membranous (strat squam epith), penile (strat squam epith) (bulbourethral /Cowper's glands, intraepith Glands of Littre), longer
female urethra
many urethral + paraurethral glands -> duct -> Skene's Gland (equiv to prostate), shorter, mucosa w/ longtid folds