Anatomy and physiology of the stomach – the organizational structure of the stomach

By | April 3, 2012

Anatomy and physiology of the stomach – the organizational structure of the stomach, the stomach with a typical four-layer structure of digestive tract were mucosa, submucosa, muscular layer and the outer (plasma) membrane. The four-story structure of the stomach, the muscular layer formed by the three smooth muscle from the outside in order for the longitudinal layer, the ring and oblique fibers. The ring the most developed, especially in the pylorus enhanced the formation of the pyloric sphincter. Have delayed emptying of stomach contents and prevent reflux of intestinal contents to the role of the stomach. Mucosal layer of soft, rich blood supply, red or reddish brown. Varying the level of gastric mucosal formation of many wrinkle bag, bend at 4_5 gastric longitudinal folds men should be relatively constant. Pyloric ring in the formation of gastric mucosal folds bag, suddenly the cavity, said the pyloric valve. Irregularly distributed throughout the mucosal surface of the minor groove, minor groove connected into a network with each other. Mesh in the gastric mucosa showed a hill-like uplift, diameter 1_6mm, said the stomach area, with a magnifying glass, the surface of the stomach area has many small depression, called gastric pits, the gastric opening.
Anatomy and physiology of the stomach – the stomach of the organizational structure of 1. Mucosa: mucosa from the epithelium, lamina propria and muscularis mucosa composition. Gastric ash slightly red. Full stomach when the surface is smooth, even stretching. Empty when the contraction, the formation of many inside the longitudinal mucosal folds Fan. The Department of mucosal folds men should continue to loose the submucosa and the mucosa was the contraction of muscle caused. With a magnifying glass to see, visible surface area of each stomach was again divided into micro-groove music is not shaping the fiber-like confrontation. In the gastric mucosa of the SEM images, you can more clearly see the folds and the small concave shape of the aid in the vertical section on the gastric mucosa, cross the ditch was sunk by the so-called gastric pits like. Full thickness of the gastric mucosa in the stomach by a large number of open pit occupied by the end of the gland. Epithelium and gastric pit during the free surface of mucosal epithelial covering its structure are identical.
1) epithelium: the gastric pits and the inter-chewing, lined with high 20_40m columnar epithelium.
2) the inherent level: residing in the lamina propria of connective tissue between the gastric muscle and mucosa, and thus between the glands and the gastric pit and neck between the accumulation of more connective tissue. Lamina propria by a thin layer of collagen fibers and reticular fibers, almost no elastic fibers. Within the fiber mesh network, in addition to containing fibroblasts seem light color of the round nuclei, but also contains many small lymphocytes and some plasma cells, eosinophilic leukocytes and mast cells. In the glandular epithelial cells, and sometimes that kind of eosinophils with coarse particles bear with material (called Russeu body) of the lymphocytes.
3) muscularis mucosa: including the inner layer and outer longitudinal layer of smooth muscle in some parts of mouth, has another outer layer. Between the glands, smooth muscle cell bundles can be stretched from the inner surface. Contraction of these muscle bundle can be compressed mucosa occurred, and promote gastric emptying.
4) mucous glands: secretion of gastric mucosa is a complex organ, contains three tubular exocrine glands and a variety of endocrine cells. A. Select the door exocrine glands are: distribution in stomach and esophageal junction of ring 1-4cm wide area, as the mucous glands, the secretion of mucus. b. oxyntic gland: distribution of the total gastric mucosa of about 2 / 3 of the fundus and gastric body. Oxyntic gland cells from the wall, the main cells and mucous neck cells of three cells. They are the secretion of hydrochloric acid, pepsinogen and mucus; c. pyloric glands: located in the pyloric part, is the secretion of alkaline mucus glands. Gastric glands and by the three secretion of gastric epithelial cell composition. Gastric mucosa also contains at least 6 kinds of endocrine cells, such as the secretion of gastrin G cells, somatostatin secretion. Plastic cells and secretion of mast cells and other groups.
Anatomy and physiology of the stomach – the stomach of the organizational structure of 2. Submucosal layer: submucosa by a dense connective tissue, which contains a small amount of fat cells and more mast cells, lymphoid cells and eosinophilic leukocyte migration, also contain large vessels, large lymphatic and venous plexus, plexus.
Anatomy and physiology of the stomach – the stomach of the organizational structure of 3. Myometrium: external muscular layer includes three layers: the outer longitudinal muscle mainly, the middle is a circular muscle, inner oblique muscle, the outermost layer of longitudinal fibers and esophagus phase continues, the muscle fibers in the stomach and the gastric greater curvature to maintain its two longitudinal bend, and behind the stomach first, outer longitudinal layer of muscle fibers gradually toward the greater curvature of stomach. Pyloric part of the longitudinal fibers are gathered into a layer of longitudinal muscle and small intestine phase continued. Three in the middle is the most structured and most continuous layer of tissue. In the pylorus, the middle form a thick ring of the sphincter to help control and discharge of gastric contents. Depends mainly on gastric emptying of the stomach muscle contraction, the muscle layers of the activities are subject to very precise regulation.
Anatomy and physiology of the stomach – the stomach of the organizational structure of 4. Adventitia <serosa>: adventitia (serosa) is the outermost layer of the stomach is coated in a thin layer outside the muscle outside the loose connective tissue, in its the surface is still covered with mesothelial. Serous membrane covering the stomach and large and small omentum, serosal phase continuity.

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