Stomach

• STOMACH
  • Shape
    • J shape , bag like ,
    • walls , organ wall , lumen walls
      • Anterior wall
      • Posterior wall
      • more specific
        • Serosa; serous coat
        • Subserosa; subserous layer
        • Muscular layer; muscular coat
          • Longitudinal layer
          • Circular layer
            • Pyloric sphincter
          • Oblique fibres
        • Submucosa
        • Mucosa; mucous membrane
          • Gastric folds; gastric rugae
          • Muscularis mucosae
          • Gastric areas
          • Villous folds
          • Gastric pits
          • Gastric glands
    • curvature
      • Greater curvature
      • Lesser curvature
        • Angular incisure
    • lumen
      • Cardia; cardial part
        • Cardial orifice
      • Fundus of stomach
      • Fornix of stomach
      • Cardial notch
      • Body of stomach
        • Gastric canal
        • Pyloric part
          • Pyloric antrum
          • Pyloric canal
      • Pylorus
        • Pyloric orifice

In classical anatomy the human stomach is divided into four sections, beginning at the cardia.

• The cardia is where the contents of the esophagus empty into the stomach.
• The fundus (from Latin 'bottom') is formed in the upper curved part.
• The body is the main, central region of the stomach.

The pylorus (from Greek 'gatekeeper') is the lower section of the stomach that empties contents into the duodenum. The cardia is defined as the region following the “z-line” of the gastroesophageal junction, the point at which the epithelium changes from stratified squamous to columnar. Near the cardia is the lower oesophageal sphincter.[8] Recent research has shown that the cardia is not an anatomically distinct region of the stomach but a region of the oesophageal lining damaged by reflux

Like the other parts of the gastrointestinal tract, the human stomach walls consist of a mucosa, submucosa, muscularis externa, subserosa and serosa.

The inner part of the lining of the stomach, the gastric mucosa, consists of an outer layer of column-shaped cells, a lamina propria, and a thin layer of smooth muscle called the muscularis mucosa. Beneath the mucosa lies the submucosa, consisting of fibrous connective tissue. Meissner's plexus is in this layer interior to the oblique muscle layer.

Outside of the submucosa lies another muscular layer, the muscularis externa. It consists of three layers of muscular fibres, with fibres lying at angles to each other.[citation needed] These are the inner oblique, middle circular, and outer longitudinal layers. The presence of the inner oblique layer is distinct from other parts of the gastrointestinal tract, which do not possess this layer. Stomach contains the thickest muscularis layer consisting of three layers, thus maximum peristalsis occurs here.

• The inner oblique layer: This layer is responsible for creating the motion that churns and physically breaks down the food. It is the only layer of the three which is not seen in other parts of the digestive system. The antrum has thicker skin cells in its walls and performs more forceful contractions than the fundus.
• The middle circular layer: At this layer, the pylorus is surrounded by a thick circular muscular wall, which is normally tonically constricted, forming a functional (if not anatomically discrete) pyloric sphincter, which controls the movement of chyme into the duodenum. This layer is concentric to the longitudinal axis of the stomach.
• Auerbach's plexus (myenteric plexus) is found between the outer longitudinal and the middle circular layer and is responsible for the innervation of both (causing peristalsis and mixing).

The outer longitudinal layer is responsible for moving the bolus towards the pylorus of the stomach through muscular shortening.

To the outside of the muscularis externa lies a serosa, consisting of layers of connective tissue continuous with the peritoneum.

FUNDUS PART OF STOMACH

PYLORUS PART OF STOMACH

Definitio (Definition)

Locatio (Location)

Forma Et Positio (Shape and position)

Magnitudo (Size) and capacity

Duas Orificia (Two orifice)

Duas Curvaturas (Two curvatures)

Duas Superficies (Two surfaces)

Duas Partes (Two parts)

Relatio Peritonealis (Peritoneal relations)

Relatio Visceralis (Visceral relations)

Interior of stomach