New

Stomach

Neelam Maurya

Stomach

STOMACH

  • Most dilatable part of alimentary tract intervening b/w oesophagus & duodenum.
  • It occupies epigastric, umblical & left hypochondriac regions.
  • When empty, it is J- shaped, & when partially distended, it becomes pyriform in shape.
  • The mean capacity of stomach is 30 ml (one ounce) at birth, 100 ml at puberty and 1.5-2 litres in adults.

Stomach has:

  1. 2 orifices (proximal cardiac orifice & distal pyloric orifice)
  2. 2 curvatures (lesser & greater)
  3. 2 surfaces (anterior/ anterosuperior & posterior/posterosuperior)
  • The most dependent part of lesser curvature is marked by angular notch (incisura angularis)
PARTS OF STOMACH
  • The stomach is divided into two parts by line drawn downwards & to the left from incisura anguaris:
  1. Cardiac part: It is divided into upper convex dome shaped ‘fundus’ & body of the stomach.
  2. Pyloric part: Is is divided into pyloric antrum & pyloric canal.

  • The posterior surface of stomach is related to structures forming the stomach bed, all of which are separated from stomach by the cavity of the lesser sac.
  • These structures forming stomach bed are–
  1. Diaphragm
  2. Left kidney
  3. Left suprarenal (adrenal) gland
  4. Pancreas (body)
  5. Transverse colon
  6. Splenic flexure of colon
  7. Splenic artery
ARTERIAL SUPPLY 
  1.  Along lesser curvature: Left gastric artery (branch of coelic trunk) & Right gastric artery (branch of proper hepatic artery)
  2.  Along greater curvature: Right gastroepiploic artery (branch of gastroduodenal artery) & left gastroepiploic artery (branch of splenic artery)
  3. Fundus: 5-7 short gastric arteries (branches of splenic artery)
→ Most consistently largest artery to stomach is left gastric artery
 
VENOUS DRAINAGE
  • The veins of stomach drain into the portal, superior mesenteric & splenic veins:
  • Right gastric vein & left gastric vein drain into portal vein.
  • Right gastric vein & left gastric vein drain into splenic vein.
  • Right gastroepiploic vein drains into superior mesenteric vein.
LYMPHATIC DRAINAGE
  • Lymphatic drainage of stomach is divided into 4 sectors:
  1. Sector a: Upper part of left 1/3rd of body along greater curvature & fundus drain into pancreaticosplenic nodes.
  2. Sector b: Body of stomach along lesser curvature drains into left gastric nodes (superior gastric nodes).
  3. Sector c: Lower part of body close to greater curvature & pyloric antrum drain into right gastroepiploic (inferior gastric) nodes which in turn drains into subpyloric (pyloric) nodes.
  4. Sector d: Pyloric canal drains into pyloric (subpyloric) nodes, hepatic nodes & left gastric nodes.

→Finally all lymphatics from these nodes drain into coelic group of lymph nodes.

NERVE SUPPLY
  • Supplied by sympathetic & parasympathetic system.
  • The sympathetic nerves are derived from T6-T9 spinal segments via greater splanchnic nerves, & coeliac & hepatic plexus.
  • Pain sensations from stomach are carried along sympathetic fibers.
  • Parasympathetic nerves are derived from right vagus which enter the abdomen anterior vagal trunk (anterior gastric nerve) from left vagus & posterior vagal trunk (posterior gastric nerve) from right vagus.
1.  Anterior vagal trunk gives: 
  1. Main gastric nerve of laterjet
  2. Pyloric branch 
  3. Hepatic branch
2. Posterior vagal trunk gives:
  1. Nerve of Grassi to fundus
  2. Coeliac branches 
  3. Main gastric nerve of laterjet
Exam Question
 
  • Stomach is derived from Foregut.
  • Cardiac orifice of stomach is located at level of T11 vertebra.
  • Chief cells are most abundant in Fundus part of the stomach.
  • Electrical pacemaker of stomach is situated in Fundus.
  • Most important blood supply to stomach left gastric artery.
  • Pain sensations from stomach are carried along sympathetic fibers.
  • The veins of stomach drain into the portal, superior mesenteric & splenic veins. 
Don’t Forget to Solve all the previous Year Question asked on Stomach
Exit mobile version