Anatomy – Foregut, Midgut, Hindgut

Sean BothamChris Harper

BoundariesForegut:

Mouth Major duodenal papillae (2nd part of duodenum).

Blood supply – Coeliac Trunk (T12)

Midgut:

Major duodenal pailliae 2/3rds along transverse colon.

Blood supply – Superior mesenteric artery (L1)

Hindgut:

2/3rds long transverse colon Upper anal canal

Blood supply – Inferior mesenteric artery (L3)

Intraperitoneal or Retroperitoneal?

Intra – SALTD SPRSS Retro – SAD PUCKER

StomachAppendixLiverTransverse ColonDuodenum (1st part)Small intestinePancreas (tail only)Sigmoid colonSpleen

Suprarenal glandsAorta & IVCDuodenum (parts 2, 3 and 4)Pancreas (all but the tail)Ureter & BladderColon (Ascending and Descending)KidneysEsophagusRectum (lower 2/3rds)

Secondary Retro – Pussy Cat Dolls

Pancreas, Colon (Ascending and Descending), Duodenum (parts 2, 3 and 4).

Foregut Blood Supply

Left gastric

Left gastroepiploic

Short gastric

Right gastroepiploic

Right gastric

Gastroduodenal

Oesophageal branches

Splenic artery Common hepatic

CT

Superior pancreaticoduodenal

Midgut Blood Supply

Inferior Pancreatico-duodenal

Jejunal

IlealIle

ocolic

Right colic

Middle colic

Marginal artery

Appendicular

SMA (L1)

Hindgut Blood Supply

Superior m

esenteric arte

ry Inferio

r mesen

teric artery

Left colic

Sigmoid

Superior rectal (top part of rectum)

Internal iliac artery(bottom part of rectum)

Lower Oesophagus

Foregut

Major Duodenal Papilla

Midgut

2/3rds along Transverse Colon

Hindgut

Upper Anal Canal

Blood Supply:

Coeliac Trunk

Superior Mesenteric Artery

Inferior Mesenteric Artery

Organs: •Oesophagus•Spleen•Stomach•Liver•Gall Bladder•Pancreas•1st and 2nd part of Duodenum

•3rd and 4th part of Duodenum•Jejunum•Ileum•Appendix•Ascending Colon•Caecum•Proximal 2/3 of Transverse Colon

•Distal 1/3 of Transverse Colon•Descending Colon•Sigmoid Colon•Rectum•Upper Anal Canal•Urogenital Sinus

Organs of the GI Tract

Pain Referral of the GI Tract

Region Epigastric

Spinal Level T5-9

Organs Referring Pain

Oesophagus, Spleen, Stomach, Liver, Gall Bladder, Pancreas, 1st and 2nd part of Duodenum

Organs Derived From

Foregut

Region Umbilical

Spinal Level T10-T11

Organs Referring Pain

3rd and 4th part of Duodenum, Jejunum, Ileum, Appendix, Ascending Colon, Caecum, Proximal 2/3 of Transverse Colon

Derived From Midgut

Region Pubic

Spinal Level T12-L1

Organs Referring Pain

Distal 1/3 of Transverse Colon, Descending Colon, Sigmoid Colon, Rectum, Upper Anal Canal, Urogenital Sinus

Derived From Hindgut

Referred pain: Pain felt at a site other than where the cause is situated. Pain in internal organs is often referred to sites distant from them. Referred pain is related to innervations of organs by

afferent pain fibres which follow similar paths as the sympathetic nervous system.