|
Gastric
The stomach is a muscular, hollow organ in the gastrointestinal tract of humans and many other animals, including several invertebrates. The stomach has a dilated structure and functions as a vital organ in the digestive system. The stomach is involved in the gastric phase of digestion, following chewing. It performs a chemical breakdown by means of enzymes and hydrochloric acid. In humans and many other animals, the stomach is located between the oesophagus and the small intestine. The stomach secretes digestive enzymes and gastric acid to aid in food digestion. The pyloric sphincter controls the passage of partially digested food (chyme) from the stomach into the duodenum, where peristalsis takes over to move this through the rest of intestines. Structure In the human digestive system, the stomach lies between the oesophagus and the duodenum (the first part of the small intestine). It is in the left upper quadrant of the abdominal cavity. The top of the stomach lies agains ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastric Acid
Gastric acid, gastric juice, or stomach acid is a digestive fluid formed within the stomach lining. With a pH between 1 and 3, gastric acid plays a key role in digestion of proteins by activating digestive enzymes, which together break down the long chains of amino acids of proteins. Gastric acid is regulated in feedback systems to increase production when needed, such as after a meal. Other cells in the stomach produce bicarbonate, a base, to buffer the fluid, ensuring a regulated pH. These cells also produce mucus – a viscous barrier to prevent gastric acid from damaging the stomach. The pancreas further produces large amounts of bicarbonate and secretes bicarbonate through the pancreatic duct to the duodenum to neutralize gastric acid passing into the digestive tract. The active components of gastric acid are protons and chloride. Often simplistically described as hydrochloric acid, these species are produced by parietal cells in the gastric glands in the stomach. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Digestive System
The human digestive system consists of the gastrointestinal tract plus the accessory organs of digestion (the tongue, salivary glands, pancreas, liver, and gallbladder). Digestion involves the breakdown of food into smaller and smaller components, until they can be absorbed and assimilated into the body. The process of digestion has three stages: the cephalic phase, the gastric phase, and the intestinal phase. The first stage, the cephalic phase of digestion, begins with secretions from gastric glands in response to the sight and smell of food. This stage includes the mechanical breakdown of food by chewing, and the chemical breakdown by digestive enzymes, that takes place in the mouth. Saliva contains the digestive enzymes amylase, and lingual lipase, secreted by the salivary and serous glands on the tongue. Chewing, in which the food is mixed with saliva, begins the mechanical process of digestion. This produces a bolus which is swallowed down the esophagus to ent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Digestive System
The human digestive system consists of the gastrointestinal tract plus the accessory organs of digestion (the tongue, salivary glands, pancreas, liver, and gallbladder). Digestion involves the breakdown of food into smaller and smaller components, until they can be absorbed and assimilated into the body. The process of digestion has three stages: the cephalic phase, the gastric phase, and the intestinal phase. The first stage, the cephalic phase of digestion, begins with secretions from gastric glands in response to the sight and smell of food. This stage includes the mechanical breakdown of food by chewing, and the chemical breakdown by digestive enzymes, that takes place in the mouth. Saliva contains the digestive enzymes amylase, and lingual lipase, secreted by the salivary and serous glands on the tongue. Chewing, in which the food is mixed with saliva, begins the mechanical process of digestion. This produces a bolus which is swallowed down the esophagus to ent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastric Phase
The nervous system, and endocrine system collaborate in the digestive system to control gastric secretions, and motility associated with the movement of food throughout the gastrointestinal tract, including peristalsis, and segmentation contractions. Gastric activity involved in digestion is divided into three phases of digestion known as the cephalic phase, the gastric phase, and the intestinal phase. These phases overlap and all three can occur simultaneously.Saladin Kenneth S.(2007) Anatomy & physiology the unity of form and function. Dubuque, IA: McGraw-Hill A fourth phase of acid secretion is known as the basal state which occurs in the times between meals (interdigestive phase). The level of acid secretion during these times is regulated by body weight, individual, number of parietal cells, and time of day. Acid secretion is lowest in the morning before awakening and highest at night. Phases Cephalic phase The cephalic phase of digestion is the stage in which the stom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oesophagus
The esophagus (American English) or oesophagus (British English; both ), non-technically known also as the food pipe or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to the stomach. The esophagus is a fibromuscular tube, about long in adults, that travels behind the trachea and heart, passes through the diaphragm, and empties into the uppermost region of the stomach. During swallowing, the epiglottis tilts backwards to prevent food from going down the larynx and lungs. The word ''oesophagus'' is from Ancient Greek οἰσοφάγος (oisophágos), from οἴσω (oísō), future form of φέρω (phérō, “I carry”) + ἔφαγον (éphagon, “I ate”). The wall of the esophagus from the lumen outwards consists of mucosa, submucosa (connective tissue), layers of muscle fibers between layers of fibrous tissue, and an outer layer of connective tissue. The mucosa is a stratified squamous epit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Left Gastric Artery
In human anatomy, the left gastric artery arises from the celiac artery and runs along the superior portion of the lesser curvature of the stomach. Branches also supply the lower esophagus. The left gastric artery anastomoses with the right gastric artery, which runs right to left. Important to note is that the esophageal branch of the left gastric artery ascends and passes through the esophageal hiatus. Clinical significance In terms of disease, the left gastric artery may be involved in peptic ulcer disease: if an ulcer erodes through the stomach mucosa into a branch of the artery, this can cause massive blood loss into the stomach, which may result in such symptoms as hematemesis or melaena. Additional images File:Stomach blood supply.svg, Blood supply to the stomach: left and right gastric artery, left and right gastro-omental artery and short gastric artery The short gastric arteries consist of from five to seven small branches, which arise from the end of the sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Right Gastric Artery
The right gastric artery arises, in most cases (53% of cases), from the proper hepatic artery, descends to the pyloric end of the stomach, and passes from right to left along its lesser curvature, supplying it with branches, and anastomosing with the left gastric artery. It can also arise from the region of division of the common hepatic artery The common hepatic artery is a short blood vessel that supplies oxygenated blood to the liver, pylorus of the stomach, duodenum, pancreas, and gallbladder. It arises from the celiac artery and has the following branches: Additional images ... (20% of cases), the left branch of the hepatic artery (15% of cases), the gastroduodenal artery (8% of cases), and most rarely, the common hepatic artery itself (4% of cases). Additional images File:Gray532.png, The celiac artery and its branches; the liver has been raised, and the lesser omentum and anterior layer of the greater omentum removed. File:Slide14fff.JPG, Right gastric arter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Short Gastric Arteries
The short gastric arteries consist of from five to seven small branches, which arise from the end of the splenic artery, and from its terminal divisions. They pass from left to right, between the layers of the gastrolienal ligament, and are distributed to the greater curvature of the stomach, anastomosing with branches of the left gastric and left gastroepiploic artery, left gastroepiploic arteries. Unlike the gastroepiploics and the left and right gastric arteries, the short gastric arteries have poor anastomoses if the splenic artery is blocked. Structure The short gastric arteries arise from the splenic artery. They run along part of the Curvatures of the stomach, greater curvature of the stomach. Function The short gastric arteries supply the Stomach, fundus of the stomach on the side of the Curvatures of the stomach, greater curvature of the stomach. References External links * {{Authority control Arteries of the abdomen Stomach ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digestive Enzyme
Digestive enzymes are a group of enzymes that break down polymeric macromolecules into their smaller building blocks, in order to facilitate their absorption into the cells of the body. Digestive enzymes are found in the digestive tracts of animals (including humans) and in the tracts of carnivorous plants, where they aid in the digestion of food, as well as inside cells, especially in their lysosomes, where they function to maintain cellular survival. Digestive enzymes of diverse specificities are found in the saliva secreted by the salivary glands, in the secretions of cells lining the stomach, in the pancreatic juice secreted by pancreatic exocrine cells, and in the secretions of cells lining the small and large intestines. Digestive enzymes are classified based on their target substrates: *Lipases split fatty acids into fats and oils. *Proteases and peptidases split proteins into small peptides and amino acids. * Amylases split carbohydrates such as starch and sugars int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digestion
Digestion is the breakdown of large insoluble food molecules into small water-soluble food molecules so that they can be absorbed into the watery blood plasma. In certain organisms, these smaller substances are absorbed through the small intestine into the blood stream. Digestion is a form of catabolism that is often divided into two processes based on how food is broken down: mechanical and chemical digestion. The term mechanical digestion refers to the physical breakdown of large pieces of food into smaller pieces which can subsequently be accessed by digestive enzymes. Mechanical digestion takes place in the mouth through mastication and in the small intestine through segmentation contractions. In chemical digestion, enzymes break down food into the small molecules the body can use. In the human digestive system, food enters the mouth and mechanical digestion of the food starts by the action of mastication (chewing), a form of mechanical digestion, and the wetting contact ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Right Gastric Vein
The right gastric vein (pyloric vein) drains blood from the lesser curvature of the stomach into the hepatic portal vein. It is part of the portal circulation. Structure The right gastric vein passes right along the lesser curvature of the stomach to the pylorus. Once there, it joins onto the portal vein before the duodenum. The prepyloric vein is the last connecting branch onto the right gastric vein, marking the end of the stomach, and draining the proximal part of the duodenum. Function The right gastric vein drains deoxygenated blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the ... from the lesser curvature of the stomach. See also * Left gastric vein References External links * () {{Authority control Veins of the torso Stomach ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Left Gastric Vein
The left gastric vein (or coronary vein) is a vein that derives from tributaries draining the lesser curvature of the stomach. Structure The left gastric vein runs from right to left along the lesser curvature of the stomach. It passes to the esophageal opening of the stomach, where it receives some esophageal veins. It then turns backward and passes from left to right behind the omental bursa. It drains into the portal vein near the superior border of the pancreas. Function The left gastric vein drains deoxygenated blood from the lesser curvature of the stomach. It also acts as collaterals between the portal vein and the systemic venous system of the lower esophagus (azygous vein). Clinical significance Esophageal and paraesophageal varices are supplied primarily by the left gastric vein (due to flow reversal) and typically drain into the azygos/ hemiazygos venous system.Siegelman, E.: "Body MRI", page 47. Saunders, 2004 See also * Right gastric vein The right ga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
