Stomach

 Stomach: 


 The stomach is a muscular sac in the upper left part of the abdomen that plays a fundamental role in digestion. The stomach develops from the foregut and connects the esophagus to the duodenum. Structurally, the stomach is J-shaped and forms a greater and lesser curvature and is roughly divided into regions: cardia, fundus, body and pylorus. At the microscopic level, the stomach wall has several layers, including mucosa, submucosa, muscularis, and serosa. The stomach is filled with glands that secrete a variety of substances involved in the digestive process. The arterial supply to the stomach comes mainly from the vessels that originate from the celiac trunk.


General description


 The stomach is a muscular sac in the upper abdomen that plays a critical role in digestion.




 Stomach functions


  1.  Food storagei
  2. Digestion
  3. Mechanically breaks down food
  4. Mixes food with gastric secretions to produce chymeSlow/controlled emptying of chyme into the small intestine
  5. Secretion of Hydrochloric acid (HCl)
  6. Activates digestive enzymes 
  7. Breaks down connective tissue in food
  8. Destroys bacteria and other pathogens
  9. digest proteins
  10. Mucus: protects gastric cells from HCl


  •  Intrinsic factor: essential for the absorption of vitamin B12


  •  Gastrin: stimulates the secretion of HCl and mucus


  •  Ghrelin (the “hunger hormone”): stimulates appetite and promotes fat storage


  •  stomach development


  •  It develops from the foregut


  •  Starts as a longitudinal tube

 The dorsal wall grows faster than its ventral wall → the sac expands posteriorly and to the left → develops a C shape


 Rotates along its longitudinal axis to its final position


 It has a dorsal and ventral mesogastrium (early mesentery that joins the primitive foregut to the posterior wall of the body):


  •  Dorsal mesogastrium → greater omentum


  •  Ventral mesogastrium → lesser omentum


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