Anatomy & Histology of Stomach

Anatomy & Histology of Stomach

Stomach

MUCOSA

Gastric Glands

Gastric pits

Surface Mucous Cell

Prepared by?

LETS PLAY A GAME!!!!

Lamina Propria and Muscularis Mucosae

MUSCULARIS EXTERNA

SUBMUCOSA

Info

Play

SEROSA

Stomach

The stomach is an expanded J-shaped organ in the upper left region of the abdominal cavity. It is continuous with the esophagus superiorly and empties into the duodenum of the small intestine inferiorly. It also continues the mechanical and chemical digestion of the bolus has been completely processed in the stomach and the product called as chyme.

It is divided into Cardiac Region, Fundic Region, Body ( corpus) and Pyloric Region

Functions of stomach is for digestion, produce acid , reservoir for food and help with vitamin absorption (Vitamin B12).

Stomach wall consist:

1. Mucosa
2. Submucosa
3. Muscularis Externa
4. Serosa

Mucosa

• The mucosa is thrown into longitudinal folds (gastric folds or rugae), which disappear when the stomach is fully distended.
• a network of shallow grooves divides the mucosa into gastric areas.
• on the mucosal surface we see small, funnel-shaped depressions (gastric pits).
• Almost the entire mucosa is occupied by simple, tubular gastric glands which open into the bottom of the gastric pits.

Surface Mucous Cells (Foveolar epithelium)

• A simple pillar lining epithelium lumens of the stomach is the surface cell of the mucosal cells, also known as the foveolar epithelium. They separate highly viscous alkaline mucus which adheres closely to the cell surface.
• The mucus protects the stomach lining by minimising the abrasion from food particles and forming a physical barrier from the hydrochloric acid. Without these mucous secretions the stomach acid would literally burn holes through the stomach wall

Gastric Pits

Invaginations of the surface epithelium form gastric pits. Gastric wells connect with gastric glands and therefore permit the delivery of glandular products into the stomach lumen. The boxes are fastened by the same surface epithelium that faces the lumen of the stomach. These are usually cut transversely rather than longitudinally in a histology part, so they are not tubular invaginations but small circular openings.

Gastric Glands

• The base of gastric pits is where gastric glands open. They can be found all over the inner surface of the stomach and are classified into three categories based on where they are situated. The fundus/body of the stomach contains the gastric glands proper (principal glands).
• Mucous neck cells, stem cells, parietal (oxyntic) cells, main (zymogenic) cells and enteroendocrine cells are composed of the same 5 cell types.

Lamina Propria and muscularis mucosae

• The propria lamina is the layer of connective tissue which is situated deep into the epithelium surface. The lymphatic vessels and blood, lymph tissue, and gastric glands are surrounded.
• The muscularis mucosae layer consists of two thin layers of smooth muscle. It separates the lamina propria from the underlying submucosa. The inner layer of muscularis mucosae consists of circular fibres while the outer layer fibres are arranged longitudinally. Its function is to help expel the secretions of the gastric glands into the stomach lumen.

SUBMUCOSA

• Contains glands only in the duodenum
• Submucosal glands of the duodenum also called as Brunners’s glands.
• Their secretion is mucous and slightly alkaline due to bicarbonate ions (pH 7-8)

MUSCULARIS EXTERNA

• The external gastric muscularis, also known as tunica muscularis, is the deep smooth muscle of the submucosa. It consists of three layers: inner, circular and outer length. The external muscle layer provides mechanical digestive churning movements.
• The myenteric (Auerbach) plexus is contained within the outside muscularis and carries sympathetic and parasympathetic fibers into the smooth muscle layers. The neural cells in this plexus are connected by the Cajal interstitial cells to smooth muscle cells (ICCs). These cells act as intrinsic pacemakers of the intestine, and mediate neural signs, which control the slow contractions of the stomach wall necessary to churn the food. In ICCs, the autonomous nervous system monitors the activity.

SEROSA

The outermost layer of the stomach wall is gastric serosa. It consists of a single epithelial layer, called mesothelium and a thin layer of connective tissue. It consists of the same layer. The mesothelium produces serious fluid that lubricates the exterior wall of the abdominal cavity and ensures its smooth movement. The serosa is continuously peritoneum parietal.

LETS PLAY A GAME!!!

XEJ6Y7

ENTER THE GAME CODE

Play

PREPARED BY:

SBC3033 Animal Morphology and Histology

Nur Amalina binti abdullah

( D20172080358 )