Category: PYLORUS(STOMACH)

HISTOLOGY OF PYLORUS(STOMACH)

HISTOLOGY OF PYLORUS(STOMACH)

IMAG0307

IDENTIFICATION POINTS

  • DEEP GASTRIC PITS
  • LAMINA PROPRIA CONTAINING PYLORIC GLANDS
  • THICKENED MIDDLE CIRCULAR MUSCLE LAYER

INTRODUCTION

–   STOMACH IS A MUSCULAR BAG LIKE STRUCTURE,STORES FOOD TEMPORARYLY  FOR FEW HOURS.

–  DIVIDED INTO 3 PARTS i.e FUNDUS,BODY AND PYLORUS.

STRUCTURE

MUCOSA:

FOLDED INTO MANY RUGAE WHICH DISSAPPEAR ON EXPANSION LINED BY SIMPLE COLUMNAR EPITHELIUM.MOST OF IT PROJECTS INTO LAMINA PROPRIA FORMING GASTRIC PITS.GASTRIC PITS ARE DEEP.

LAMINA PROPRIA:

RICH IN MUCOUS SECRETING PYLORIC GLANDS.

MUSCULARIS MUCOSA/INTERNA:

CONSISTS OF INNER CIRCULAR AND OUTER LONGITUDINAL MUSCLE LAYERS.

SUBMUCOSA:

MADE UP OF LOOSE AREOLAR CONNECTIVE TISSUE.MEISSENER’S PLEXUS OF NERVE FIBRES ARE PRESENT.

MUSCULARIS EXTERNA:

CONSISTS OF INNER OBLIQUE,MIDDLE CIRCULAR AND OUTER LONGITUDINAL MUSCLE LAYERS. IN BETWEEN CIRCULAR AND LONGITUDINAL MUSCLE LAYERS, FEW MYENTERIC OR AUERBACH’S PLEXUS OF NERVE FIBRES ARE SEEN.MIDDLE CIRCULAR MUSCLE LAYER IS THICKER.

SEROSA:

OUTER MOST LAYER MADE UP OF FEW CONNECTIVE TISSUE CELLS AND FIBRES, COVERED BY MESOTHELIUM OF VISCERAL PERITONEUM.

FUNCTIONS:

  • SIMPLE COLUMNAR EPITHELIUM PERFORMS SECRETORY AND ABSORPTIVE FUNCTION.
  • SUBMUCOSA IS DEFENSIVE AND NUTRITIVE IN FUCTION.
  • MUSCULARIS EXTERNA HELPS IN CHURNING FOOD PARTICLES i.e PERISTALSIS.
  • SEROSA IS SUPPORTIVE AND PROTECTIVE IN FUNCTION.

CLINICAL

  •   INFLAMMATION OF GASTRIC MUSCOSA BY ‘HELICOBACTER PYLORI’ CAUSING GASTRITIS.
  • HYPERSECRETION OF HCL AND PEPSIN ENZYMES CAUSING PEPTIC ULCERS.
  • UNCONTROLLED ABNORMAL PROLIFERATION OF SURFACE EPITHELIUM OF STOMACH LEADS TO GASTRIC CARCINOMA.