GI Flashcards
Foregut
Mouth to the common bile duct
midgut
common bile duct to 2/3 of the transverse colon
hindgut
2/3rds of the transverse colon to the anal canal
blood supply of the foregut
coeliac artery
components of the foregut
pharynx
oesophagus
stomach
proximal half of duodenum and the derivative:
liver, pancreas, gallbladder, spleen
blood supply of the midgut
superior mesenteric artery
components of the midgut
distal half of the duodenum
jejunum
ileum
caecum
appendix
ascending colon
right/ first 2/3 of transverse colon
blood supply of the hindgut
inferior mesenteric artery
components of the hindgut
last third of transverse colon
descending colon
sigmoid colon
rectum
anal canal
embryonic folding - during which week does the embryo begin to fold from a flat trilaminar disc to a cylinder?
4th
how many planes does folding occur in? which ones?
two, horizontal and medial
why does folding occur in two planes?
differing rates of growth of the embryonic structures
what does the horizontal folding result in?
two lateral body folds
what does the medial folding produce?
cranial and caudal folds
does folding of the planes occur simultaneously?
yes
which part of the embryo forms the GI tract primarily
endoderm
how is the primitive gut tube formed
as embryonic folding continues, the endoderm moves towards the midline and fuses
incorporating the dorsal part of the yolk sac to form the primitive gut tube
What components of the embryo is the primitive gut tube formed from?
Endoderm and visceral mesoderm
what does the endoderm give rise to
epithelial lining of the digestive tract
liver hepatocytes
endocrine and exocrine cells of the pancreas
What does the visceral mesoderm give rise to?
muscle, connective tissue and peritoneal components of the wall of the gut
connective tissue for the glands
what parts does the primitive gut tube differentiate into?
foregut, midgut and hindgut
what end of the embryo is the foregut on?
cranial
what is the oropharyngeal membrane?
temporarily closes the foregut at the cranial end
ruptures at the end of the 4th week to form the mouth
when is the midgut connected to the yolk sac until?
5th week
what is the vitelline duct?
the connection between the embryo and the yolk sac that narrows as the embryo folds
what end of the embryo does the hindgut lie
caudal
what is the cloacal membrane?
temporarily closes the hindgut at the caudal end
ruptures to form the anus at the 7th week
What part of the gut are the pharyngeal arches in?
Foregut
where do the pharyngeal arches start and finish?
oropharyngeal membrane to the respiratory diverticulum
