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Renin Angiotensin Mechanism.

Digestive System: Stomach.

 

Stomach:

  • Stomach is present between the Oesophagus and First part of the small intestine i.e. duodenum.

  • It is a “J” shaped organ present on the left side of the body and just below the diaphragm.

  • It is divided into “Four” parts as follows,

    • Cardia: Superior opening, contains “Cardiac Sphincter”. 

    • Fundus: Superior rounded portion.

    • Body: Central portion below the fundus.

    • Pylorus: last part, below body, made up of two parts,

      • Pyloric Antrum:

      • Pyloric canal: It contains “Pyloric Sphincter”.

  • Stomach Cells of Stomach:

  1. Mucous cells: secrete mucus that protects against stress and acid.

  2. Parietal cells: secrete hydrochloric acid

  3. Chief cells: secrete pepsin, a proteolytic enzyme

  4. G cells: secrete the hormone gastrin

  • Functions of Stomach:

    • Reservoir of food.

    • Secretes gastric acid.

    • Gastric acid aids in the process of digestion.

    • Acidic pH in the stomach kills the microbes present in the food.

    • The churning movements of the stomach cause mixing of food with gastric juices.

    • The pepsin present in gastric juice helps in protein digestion.

    • The gastric lipases start digestion of fats.

    • Acidic drugs like Aspirin get absorbed from the stomach.

    • Mucosal membrane and mucus of the stomach protects the linings of the stomach from gastric acid.

    • Cardiac sphincter prevents reflux of acidic contents in the oesophagus.

    • Pyloric sphincter regulates entry of chyme in the small intestine and reverse entry into the stomach.

Commonly Asked Questions.

  1. Draw a well labelled diagram showing anatomy of the stomach.

  2. Give different functions of the stomach.

  3. Write a short note on “Stomach”.
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