GI Embryology Flashcards
Foregut starts from the … to the …
mouth
common bile duct
Midgut starts from the … to the …
common bile ducts
2/3rds of transverse colon
Hindgut starts from … to the …
2/3rds of the transverse colon
anal canal
Blood supply of foregut
Coeliac artery
Components of foregut
Pharynx
Oesophagus
Stomach
Proximal half of duodenum and the derivative (liver, biliary apparatus, pancreas)
Blood supply of midgut
Superior mesenteric artery
Components of midgut
Distal half of duodenum Jejenum Ileum Caecum Appendix Ascending colon Right 2/3rds of transverse colon
Blood supply of hindgut
Inferior mesenteric artery
Components of hindgut
Left 1/3 of transverse colon Descending colon Sigmoid colon Rectum Anal canal
Embryonic folding
4th week - Embryonic folding: from flat, trilamminar disc into a cylinder
Folding occurs in horizontal and medial planes simultaneously
Folding in HORIZONTAL PLANE = two lateral body folds
Folding in MEDIAL PLANE = cranial and caudal folds
What is responsible for development of GI tract?
Endoderm
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
The primitive gut tube is formed from
the endoderm
Visceral mesoderm
Endoderm gives rise to
- Epithelial lining of digestive tract
- Hepatocytes of the liver
- Endocrine and exocrine cells of the pancreas
Visceral mesoderm gives rise to
- Muscle, connective tissue and peritoneal components of the wall of the gut
- Connective tissue for the glands