L2 epith tiss

Question 1

LO2: Desc how epith classif.

Answer 1

simp=1lay, stratif=multip.
- simp squam- thin cytop, on thin BM.
LOCAT- bowmans caps. B+LV where called endothel.lining bod cavs called mesothelium. alveoli. loop of henle. inn and mid ear.
FUNC- exch gas and nutr, flit cell, reg platelet coag.
- simp cub-
LOCAT- panc duct. thyroid gl follics. kidney ducts. sec part of sweat gl. small ducts of many exoc gls. surf ovary.
FUNC- synth, store and transp thyroxine. reabs water and urea. abs and conduit. abs and sec. barr. horm synth, stor and mobil. \
- simp col- nuc often in basal part.
LOCAT- crypts of lieberkuhn colon mucosa. gall bladd. parotid duct. fallop tube. stom lining. gastric gl. colon.
simp col with microvilli- junc complex adjoin apical part has desmosomes, gap junc, zonula occludens and adherens, seps luminal from intercell space.
LOCAT- small int.
FUNC- abs, sec, lubric, transp.
-pseudistrat- all contact BM. often ciliated.
LOCAT- upper resp. epididymis. parotid gl. audit tube part of tympanic cav. lacrimal sac. large excret ducts.
FUNC- sec and coduit, abs, mucus sec, partic trapp and re,.
- strat squam-
LOCAT- vagina, oesoph, epiglottis tracheal side, cornea, oral cav, larynx, analcanal, inner eyelid.
FUNC- protec abrs, reduc water loss remains moist.
- kerat strat squam- outer dead no nuc.
LOCAT- epidermis. lim oral cav.
FUNC- protec abras. prev water loss. prev microbe ingress. shield UV.
-transit- col/cub to flat.
LOCAT- ureter, bladd, urethra, renal calyces.
FUNC- distension, protec underl tiss from chem.

Question 2

LO3: BM posit, struc, func.

Answer 2

• thin flexib acell lay btw epith and subtend CT.
• basal lamina laid by epith sois closest to them. var thickness retic fibrils t3 coll elab by CT.
• strng flexib lay epith adhere. molec and cell filt. malig penet rel to prog.

Question 3

LO4: why diff rates renewal.

Answer 3

• deps on locta and func.
• const except injury.
• skin 28d from basal div to shed. small int repl by regen cells from base of crypts ev 4-6d. some not renewed once ad but polif trigg if dam or inj.

Question 4

LO5: surf spec and how struc rel func.

Answer 4

• microvilli- incr sa eg int. actin=shape.
• stereocilia v long microvilli apical eg epididymis.
• cilia- motile via mt’s eg resp.

Question 5

LO1: define epithelia. derivs of epith.

Answer 5

• sheets contig cells var emb ori cov ext surf of bod and line int surfs. ext skin. int open GI, resp, GU. int closed pericard, peural, peritoneum, B+LV.
• ectoderm= epidermis, corneal epith.
  mesoderm= CLOSED eg GU, L+BV, pericard, pleural, peritoneal.
  endoderm= mostly OPEN eg resp, GI, liver and gls eg thyroid, thymus, saliv.

Question 6

simple squam

Answer 6

• FUNC- gas exch, barr, lubric, filt cells, reg platelet coag.
• LOCAT- B+LV, bod cavs, loop of henle, bowmans capsule, inn and mid ear, alveoli.

Question 7

simp cub

Answer 7

• FUNC- abs, conduit, sec. horm synth, stor and mobil. barr. reabs water and urea.
• LOCAT- thyroid, exoc ducts eg panc,sweat, kidney tubules, ovary

Question 8

simp col.

Answer 8

-FUNC- abs and sec, lubric, transp.
-LOCAT- crypts, gallb, parotid, stom, gastric gl, fallop, colon. uterus, ductili efferentes, oviducts. large exoc ducts.
with mvilli and junc complex small int.

Question 9

pseudostrat col.

Answer 9

• FUNC- sec, conduit. abs. mucus sec. trapp and expuls of partics.
• LOCAT- upper resp nasal, trach, bronchi. epididymis. parotid. lacrimal sac. large excret duct. audit tube and part tympanic cav.

Question 10

strat squam

Answer 10

• FUNC- protec abras, maint moist.

- LOCAT-vagina, oesoph, trach side epiglottis, cornea, anal canal, larynx, oral cav, eyelid inner.

Question 11

kerat stratif squam.

Answer 11

• FUNC- protec abras and trauma, prev water loss, prev microbe ent, shield UV.
• LOCAT- lim oral cav, skin.

Question 12

transit.

Answer 12

• FUNC- distension, protec from chem.

- LOCAT- uerter, urethra, bladd, renal calyces.