1 / 17

Histology of digestive system stomach-fundus & pylorus

Histology of digestive system stomach-fundus & pylorus. INTRODUCTION. BASIC PATTERN: I) Mucosa - Epithelium - Lamina propria - Muscularis Mucosae II) Submucosa III) Muscularis Externa IV) Serous layer / Adventitial layer. STOMACH.

janed
Download Presentation

Histology of digestive system stomach-fundus & pylorus

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Histology of digestive system stomach-fundus & pylorus

  2. INTRODUCTION • BASIC PATTERN: I) Mucosa - Epithelium - Lamina propria - Muscularis Mucosae II) Submucosa III) Muscularis Externa IV) Serous layer / Adventitial layer

  3. STOMACH • Stomach is a dilated segment of the digestive tract, that digest food and secrets hormone • There are three histological regions: • Cardia • Fundus and body • Pylorus • The fundus and body are identical in microscopic structure • The mucosa and submucosa of the undistended stomach lie in longitudinally directed folds known as rugae • When the stomach is filled with food, folds flatten out

  4. Cardiac region of the stomach Mucosa: • Epithelial lining at the cardio-oesophageal junction changes from stratified sq. to simple columnar epithelium • Presence of Mucous surface cells and cardiac glands Submucosa: Consists of Meissner’s plexus and blood vessels

  5. Muscularis externa: Inner – Oblique Middle – circular Outer – longitudinal Myenteric plexus between muscle layers Serosa – Simple squamous epithelium resting on a thin layer of connective tissue

  6. Stomach - fundus • Mucosa: - Lining Epithelium – Simple columnar epithelium that invaginates to various extents into the lamina propria, forming gastric pits. - These cells are involved in mucus secretion. The mucus protects the epithelial lining from damage due to the presence of acid in the stomach.

  7. Stomach – fundus • Lamina propria: - Small tubular fundic/gastric glands are present. - Types of cells: i) Mucous neck cells – Located just below gastric pit. - Columnar in shape - Contain mucinogen granules in apical cytoplasm, while nuclei are situated basally. - Produces soluble mucus

  8. Parietal or oxyntic cells: - They are large, ovoid or polyhedral cells with a large central nucleus. - More numerous in the upper half of the gland than in the lower half - Secretes HCL and intrinsic factor. Intrinsic factor combines with vitamin B12 to form a complex necessary for erythrocytes formation.

  9. Chief or zymogenic cells: - Located in the lower 1/3rd of gastric glands. - Contain rough endoplasmic reticulum near the base, secretory granules near their apex and a small golgi apparatus. - Secrete pepsinogen which is converted into pepsin in an acid environment.

  10. Enteroendocrine cells: - Located in the basal portion of gastric glands - Secretes serotonin, histamine and gastrin. These are endocrine cells which release their products into the blood vessels. MUSCULARIS MUCOSAE: - It consists of two thin layer of smooth muscles. i.e., Outer longitudinal and inner circular

  11. SUBMUCOSA: - Consists of blood vessels, lymphatic vessels and Meissner’s plexus. MUSCULARIS EXTERNA: Inner: Oblique Middle: circular Outer: Longitudinal SEROSA: Outermost layers of the stomach which consists of loose connective tissue covered by mesothelium

  12. STOMACH - PYLORUS • MUCOSA: - Epithelium: Simple columnar as in fundic part - Pyloric glands occupy the lamina propria - Gastric pits are deeper - Glands are short,tortuous and branched - Produce mucus and gastrin - Muscularis mucosa and Submucosa are similar to fundic part

  13. MUSCULARIS EXTERNA: Inner: Oblique Middle: circular Outer: Longitudinal Similar to Fundic part, but the circular fibres are much thickened to form pyloric sphincter

  14. Difference between cardiac, fundus & body, and pylorus 15

  15. CLINICAL ASPECTS • GASTRO- ESOPHAGEAL REFLUX DISORDER: A condition which is characterised by the compromised state of the lower oesophageal sphincter, which leads to reflux of food and acid into oesophagus.

  16. THANK YOU

More Related