The morphology and distribution of the stomach

People usually don't know much about the shape and structure of the stomach. In fact, the structure of the gastrointestinal tract is very complex. If there are some problems, it will lead to various diseases. Therefore, the best way is to protect your gastrointestinal tract, especially the mucosa in the gastrointestinal tract, which is a protective film and must not be damaged.

Briefly describe the shape and divisions of the stomach

Low-power observation shows that the stomach wall is divided into 4 layers from inside to outside.

(1) Mucous membrane: It is divided into three layers from inside to outside.

① Epithelium: It is a single layer of columnar epithelium. The epithelium is sunken downward to form gastric pits. The nucleus of the columnar cells is located at the base, and the top cytoplasm is filled with mucin granules and is a lightly stained transparent area, with clear boundaries between cells. Tubular structures with the same structure as columnar cells are often seen in the connective tissue deep in the epithelium, which are the cross-sections of nearby gastric pits.

② Lamina propria: connective tissue, containing blood vessels, lymphatic tissue, scattered smooth muscle cells and a large number of fundic glands. The fundic glands are located between the gastric pits and the mucosal muscles. They are single tubular glands with small glandular cavities that are not easily visible. They are mainly composed of parietal cells and chief cells.

③ Muscularis mucosa: thin, composed of two layers of smooth muscle, inner circular and outer longitudinal.

(2) Submucosal layer: loose connective tissue, containing larger blood vessels, lymphatic vessels and submucosal nerve plexus, which is composed of several nerve cells and unmyelinated nerve fibers. Can it be seen? (3) Muscular layer: thicker, composed of smooth muscle with inner oblique, middle circular and outer longitudinal lines.

(4) Adventitia: It is composed of loose connective tissue and mesothelium on the outer surface. High-power observation: The fundic glands are composed of 5 types of glandular cells, with parietal cells and chief cells being the focus.

(1) Parietal cells: There are more of them in the neck and body of the fundic gland. The cells are large and round or triangular in shape. The nucleus is round, often binucleated, and located in the center of the cell. The cytoplasm is stained red.

(2) Chief cells: There are many of them, mostly in the body and base of the fundic gland. The cells are columnar. The nucleus is round and located at the base. The cytoplasm is stained blue, and the small vacuoles at the top of the cells are caused by the dissolution of zymogen granules.

(3) Neck mucous cells: small in number, located in the neck. The cells are columnar or cup-shaped. The nucleus is oblate or triangular and located at the base. The cytoplasm is filled with mucinous granules.

(4) Endocrine cells and stem cells are difficult to distinguish in HE-stained specimens.

The stomach is located below the diaphragm and in the upper part of the abdominal cavity. Traditional Chinese medicine divides it into three parts: upper, middle, and lower. The upper part of the stomach is called Shangwan, including the cardia; the middle part is called Zhongwan, which is the body of the stomach; the lower part is called Xiawan, including the pylorus. The main physiological function of the stomach is to receive and digest food and drink. The stomach is in harmony with the spleen and is the exterior and interior of the stomach.