Gastrointestinal anatomy
Embryonic folding cuts of dorsal part of yolk sac to form primitive gut (single hollow tube)
divided by blood supply:
failure of closure of the vitelline duct (connection with yolk sac) proximally leads to Meckel's Diverticulum
protein loosing enteropathy (faecal alpha 1 antitrypsin)
Liver
Pancreas (Exocrine)
Bilary Tree
L+R hepatic ducts > common hepatic duct
joins cystic duct of gall bladder forming common bile duct
joins pancreatic duct forming Ampulla of Vater
drains through sphincter of oddi
entering the 2nd part of the duodenum
defines the junction of the fore and midgut
i.e. supply above by coeliac truck (inc spleen, liver and all but head of panc) and below by superior mesenteric artery (to traverse colon inc head of panc)
divided by blood supply:
- Foregut (coeliac): mouth to sphincter of oddi (Lungs bud from oesoph, Liver and pancreas from ?duod)
- Midgut (SMA): Oddi to 2nd half of transverse colon
- Hindgut (IMA) Transverse to rectum
failure of closure of the vitelline duct (connection with yolk sac) proximally leads to Meckel's Diverticulum
protein loosing enteropathy (faecal alpha 1 antitrypsin)
Liver
Pancreas (Exocrine)
- elastase: breaks down elastin (elastic protein in connective tissue) (faecal elastase)
- lipase: breaks down lipids
- amylase: breaks down carbohydrates
Bilary Tree
L+R hepatic ducts > common hepatic duct
joins cystic duct of gall bladder forming common bile duct
joins pancreatic duct forming Ampulla of Vater
drains through sphincter of oddi
entering the 2nd part of the duodenum
defines the junction of the fore and midgut
i.e. supply above by coeliac truck (inc spleen, liver and all but head of panc) and below by superior mesenteric artery (to traverse colon inc head of panc)