Flashcards in L4 dev of GIT Deck (7)
LO2: how coelomic and perit cavs dev.
- intraemb coelom- primord all bod cavs. mesod mid lay- somat mesod outs, splanch inside. mesod lat sp opens as emb folds, leafs meet up=sp, cyling shape.
coelom bgins 1 lay cav, endod lined tube. later subdiv by fut diaph into abdo and thoracic cav.
-perit and perit cav: perit mem lines coelom, invests viscera. poten sp. gut tube elongs and rolls, perit also changes.
LO3: fate emb dorsal and ventral mesents.
-mesent=doub lay perit susp gut tube from abdo wall. blood and nerve supp and mobil. splanch mesod susp primit gut in coelom, condensat this mesod- mesent. dorsal mesent susps ent gut tube from dorsal wall. went only in reg of foreg- free edge.
LO4: how greater and lesser omenta and mesent of small int dev. relate to arr in ad and neonate.
-dorsal and vent mesent div cav to L and R sacs in foreg only. L greater sac, R lesser beh stom as lose vent att.
omenta= spec regs perit. greater from dorsal mesent. lesser vent, free edge portal triad.
-greater and lesser sacs and omenta formed by rotat stom.
round longit axis and anteropost. init this puts greater curvat R, lesser L then cardia and pyloris move horiz and push greater curv infer. stom rotat puts vagus nerves ant and post. shidt cardia and pyloris from midline=oblique. moves lesser sac beh stom and forms greater omentum.
-liv dev in leaves of vent mesent.
-perit reflec- change in direc from pariet to visc perit. from mesent to visc perit. etc.
LO5: why some abdo organs retroperit. eg asc and desc colon and duod.
-retroprit no susp in abo cav, never had mesent. secondaril retrop had mesent but fused at post abdo wall.
-foreg derivs- foreg=lung bud to liver bud.
wk4 resp divertic forms in vent wall foreg at junc with pharyng gut. resp primordium (vent). oesoph (dorsal).
trancheosoph septum forms x divertic, abnorm posit 1/3000 live birtheg proxim blind end, tracheosoph fistula, oesoph atresia.
-stom- faster growth dorsal border. rotat changes posit of dorsal and vent mesents- omental bursa formed, lesser displ post from R.
-foreg der gls- vent mesent= liv, biliary sys, ucinate proc, head panc.
dorsal =sup head, neck, bod, tail panc.
-liver- from hepat bud in vent mesent btw 2 leafs. perit reflecs- wk6 bare are top, lesser oment, falcif lig to ant wall, splits as liver grew ins 2 mesent. ant att is deriv of vent mesent. bare area atts diaph.
-duod- caudal foreg and cranial midg. gorw rap=c loop when stom rotates ant post. wk 5 and 6 lumen destr and re canal. stom rotat pushes R and post.
LO6: desc dev musc and fascial lays abdo wall incl inguinal canal.
-sec retroperit- mesent lost fus post wall pariet perit due to GIT expans= fusion fascia.
eg stom grow pushed ag post wall, apriet perit paper over it=fascia.
sec retroperit foreg=duod excep cap, panc.
LO7: expl dev basis umb and inguinal hernia.