What Is the Pyloric Sphincter?
The muscular layer of the stomach is composed of three smooth muscles, which are the longitudinal layer, the annular layer, and the oblique layer in order from the outside to the inside. The effect of the substance refluxing to the stomach.
- Chinese name
- Pyloric sphincter
- Location
- Deep pyloric valve
- Category
- Human organs and tissues
- Function
- Delay gastric emptying and prevent regurgitation of intestinal contents
- The muscular layer of the stomach is composed of three smooth muscles, which are the longitudinal layer, the annular layer, and the oblique layer in order from the outside to the inside. The effect of the substance refluxing to the stomach.
Anatomy of the stomach wall of the pyloric sphincter
- Divided into 4 layers: mucosal layer. It is the innermost layer of the stomach wall. It is rich in blood vessels and is red. It is composed of a layer of columnar epithelial cells. The surface has dense dimples and is located at the openings of a large number of glands in the mucosa. Columnar epithelial cells secrete mucus containing neutral polysaccharide mucin. There are still a large number of gastric glands in this layer. There is a thin layer of intertwined muscle bundles at the base of the gastric mucosal glands, called the muscularis mucosa. When the stomach is emptied, the mucosa shows many folds. The submucosa is composed of loose connective tissue and elastic fibers. It is rich in blood vessels and lymphatic vessels and the Meissner neural network. muscular layer. It consists of three layers of muscle fibers in different directions. The inner layer is oblique fibers and the middle layer is circular fibers. It is the thickest in the pylorus and finally forms the portal sphincter. The outer layer is a longitudinal fiber. serous membrane layer. The peritoneal layer.
Acute gastric dilation of pyloric sphincter
- Acute gastric dilation refers to the extreme enlargement of the non-mechanically obstructed gastric cavity with a large retention of gastric contents. The cause is gastric paralysis caused by various reasons, most of which occur after meals and surgery. In the past, it was thought that visceral nerves were strongly stimulated during abdominal surgery, causing gastric wall reflex inhibition, making the gastric wall muscles weak and weak, and then forming gastric dilation; Recently, according to domestic reports, about 80% of the disease occurs in full meals, especially after overeating, and only a few occur after surgery. After overeating, the gastric cavity expands sharply, and the muscularis of the gastric wall is paralyzed due to excessive stretching, which eventually leads to dilation. In addition, abdominal trauma, abdominal inflammation, severe pain, excessive fatigue, malnutrition, and general weakness can promote the occurrence and development of gastric paralysis. With the increasing expansion of the stomach, the gastric body occupies the entire upper abdomen and even the entire abdomen, the stomach wall becomes thin and brittle, the mucosal folds disappear, bloody exudate appears in the stomach cavity, and even gastric wall necrosis and perforation produce peritonitis. Secondly, due to a large amount of exudation in the stomach, water and electrolyte disorders occur due to the loss of body fluids, and finally acid-base imbalance, blood volume reduction and peripheral circulation failure.
- The clinical manifestations are persistent upper abdominal fullness and dull pain after a full meal, which may be accompanied by paroxysmal aggravation, the degree is not severe, followed by frequent vomiting, a small amount, and symptoms after vomiting are not alleviated. It can be aspirated if placed in the stomach Large amounts of gas and fluids relieve symptoms. The vomit is turbid liquid at first, but it may turn brown after bleeding. Physical examination can reveal that the abdomen is highly swollen, especially in the upper abdomen, and the sound of vibrating water can be heard. The abdomen is generally soft, and sometimes there is scattered tenderness, and bowel sounds are weakened. In the later stage, signs of peritonitis such as abdominal muscle rigidity, total abdominal tenderness, and disappearance of bowel sounds. Most of the body conditions have varying degrees of dehydration, rapid pulse rate, shortness of breath, and finally shock and coma. Gastric bubbles and fluid level enlargement can be seen on the plain film of the abdomen, and free gas can be seen under the diaphragm after gastric perforation. Rarely self-healing and high mortality. In recent years, the mortality rate has decreased significantly. Avoid overeating, and pay attention to the treatment before and after abdominal surgery is the most important measure to prevent acute gastric dilatation, such as routine application of gastric tube decompression after major abdominal surgery; use of appropriate anesthesia; gentle operation during surgery to minimize tissue damage.
- Non-surgical treatment should be the main method, especially when it occurs after surgery. Most early applications of gastric tube decompression can achieve satisfactory results. Stomach lavage caused by a full meal should be lavaged, and excessive water and excessive force should be avoided when rinsing. If the symptoms still do not improve, or signs of peritonitis with perforation of gastric wall necrosis, surgery should be taken. The operation method should be different according to the specific conditions of the patient. If the stomach wall is still intact, the stomach wall can be cut and the contents of the stomach can be removed. Gastrectomy.