Stomach

Parts

1. Cardia
2. Fundus
3. Body
4. Antrum
5. Pylorus

• Pyloric sphincter anatomaical as well as physiological mechanism
• Caria is not demarcated by distinct sphincter

Relations

1. Anterior: abdominal wall, left costal margin, diaphragm, left lobe of liver
2. Posterior: lesser sac (separates stomach from pancreas, transverse colon, left kidney)
3. Superiorly: dome of diaphragm
   • Lesser omentum attached along lesser curvature of the sstomach
   • Greater omentum along greater curvature (contains vascular and lymphatic supply to stomach)

Blood supply

1. Left gastric artery (coeliac axis T12)
2. Right gastric (from hepatic artery T12)
3. Right gastro-epiploic artery (gastroduodenal branch of hepatic artery)
4. Left gastro-epiploic artery (splenic artery)

Lymph drainage

• Accompanies blood vessels
• 3 drainage zones: I - superior 2/3 ; II - right 2/3 of inferior 1/3; left 1/3 of inferior 1/3
• Extensive lymphatic drainage and technical impossibility of complete removal is one of the serious problems in dealing with stomach cancer

Nerve supply

• Vagus

Epiploic foramen of Winslow

boundaries

1. Anterior: free edge of lesser omentum (containing portal vein, bile duct, hepatic artery) *pringles manoeuvre
2. Posterior: inferior vena cava
3. Superior: caudate lobe of liver
4. Inferior: 1st part of duodenum

Duodenum

1. C-shaped around head of pancreas
2. 25cm long
3. 4 sections:
   • 1st: ascends gastroduodenal junction, overlapped by liver and GB
   • 2nd: descends curve around head of pancreas - Main pancreatic duct of Wirsung (guarded by sphincter of Oddi) + subsidary pancreatic duct of Santorini
   • 3rd: runs transversely to left crossing inferior vena cava, aorta and 3rd lumbar vertebra
   • 4th: ascends upwards and to the left, Ligament of Treitz at duodenal termination (peritoneal fold descending from right crus of diaphragm ti duodenal termination)
4. Blood supply:

Rectum

1. 12cm in lenth
2. Commences anterior 1/3 segment of sacrum and ends at level of apex of prostate
3. Curved in man to fit sacral hollow
4. Presents "Valves of houston" projecting left, right and left from above downwards

Arterial Supply of Gut

1. Foregut: oesophagus, stomach, duodenum as far as entry of bile duct
   Coeliac axis T12

   

   • Splenic
   • Left gastric
   • (right) hepatic
2. Midgut: mid-duodenum to distal transverse colon
   Superior mesenteric artery L1

   

   • Inferior pancreato-duodenal artery
   • Jejunal / ileal branches - supply bulk of small intestine
   • Ileocolic (ileum, caecum, appendix)
   • right colic
   • Middle colic
3. Hindgut: distal transverse colon to rectum
   Inferior mesenteric artery L3
   • left colic
   • sigmoid branches
   • Superior rectal artery

Portal system of veins

• Drains blood to liver from abdominal part of alimentary canal (excluding anus), spleen, pancreas, GB and ducts
• Distal tributaries correspond to and accompany the branches of the coeliac, superior and inferior mesenteric arteries

Portal vein composed of (forms behind pancreas)

1. Splenic vein (+ inferior mesenteric vein)
2. Superior mesenteric vein

Porto-systemic anastamoses (occurs if blockage pre-hepatic, hepatic or post hepatic)

1. oesophagus + left gastric vein + aygous system
2. Superior rectal branch of inferior mesenteric vein + inferior rectal veins draining into iliac vein
3. Portal tributaries of mesentry and mesocolon + retroperitoneal veins communicating with renal, lumbar and phrenic veins
4. Portal branches of liver + veins of abdominal wall
5. Portal branches of liver + veins of diaphragm