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Cystic Plexus
The cystic plexus is the derivation of the hepatic plexus, which is the largest offshoot from the celiac plexus. Formed by branches from the celiac plexus, the right and left vagi and the right phrenic nerve, parasympathetic nerves are motor to the musculature of the gall bladder and bile ducts, but inhibitory to the sphincters A sphincter is a circular muscle that normally maintains constriction of a natural body passage or orifice and which relaxes as required by normal physiological functioning. Sphincters are found in many animals. There are over 60 types in the hum .... Sympathetic nerves derived from thoracic seven to nine segments are vasomotor and motor to sphincters. It supplies the gall bladder, common hepatic duct, cystic duct and upper part of the bile duct. The lower part of the bile duct is supplied by the nerve plexus around the superior pancreaticoduodenal artery. References {{anatomy-stub Nerve plexus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepatic Plexus
The hepatic plexus, the largest offset from the celiac plexus, receives filaments from the left vagus and right phrenic nerves. It accompanies the hepatic artery, ramifying upon its branches, and upon those of the portal vein in the substance of the liver. Branches from this plexus accompany all the divisions of the hepatic artery. A considerable plexus accompanies the gastroduodenal artery and is continued as the inferior gastric plexus on the right gastroepiploic artery along the greater curvature of the stomach 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 i ..., where it unites with offshoots from the lienal plexus. Cystic plexus is the derivation of hepatic plexus. References External links * {{Authority control Nerve plexus Nerves of the torso Vagus nerve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Celiac Plexus
The celiac plexus, also known as the solar plexus because of its radiating nerve fibers, is a complex network of nerves located in the abdomen, near where the celiac trunk, superior mesenteric artery, and renal arteries branch from the abdominal aorta. It is behind the stomach and the omental bursa, and in front of the crura of the diaphragm, on the level of the first lumbar vertebra. The plexus is formed in part by the greater and lesser splanchnic nerves of both sides, and fibers from the anterior and posterior vagal trunks. The celiac plexus proper consists of the celiac ganglia with a network of interconnecting fibers. The aorticorenal ganglia are often considered to be part of the celiac ganglia, and thus, part of the plexus. Structure The celiac plexus includes a number of smaller plexuses: Other plexuses that are derived from the celiac plexus: Terminology The celiac plexus is often popularly referred to as the solar plexus. In the context of sparring or in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phrenic Nerve
The phrenic nerve is a mixed motor/sensory nerve which originates from the C3-C5 spinal nerves in the neck. The nerve is important for breathing because it provides exclusive motor control of the diaphragm, the primary muscle of respiration. In humans, the right and left phrenic nerves are primarily supplied by the C4 spinal nerve, but there is also contribution from the C3 and C5 spinal nerves. From its origin in the neck, the nerve travels downward into the chest to pass between the heart and lungs towards the diaphragm. In addition to motor fibers, the phrenic nerve contains sensory fibers, which receive input from the central tendon of the diaphragm and the mediastinal pleura, as well as some sympathetic nerve fibers. Although the nerve receives contributions from nerves roots of the cervical plexus and the brachial plexus, it is usually considered separate from either plexus. The name of the nerve comes from Ancient Greek ''phren'' 'diaphragm'. Structure The phrenic n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parasympathetic Nerve
The parasympathetic nervous system (PSNS) is one of the three divisions of the autonomic nervous system, the others being the sympathetic nervous system and the enteric nervous system. The enteric nervous system is sometimes considered part of the autonomic nervous system, and sometimes considered an independent system. The autonomic nervous system is responsible for regulating the body's unconscious actions. The parasympathetic system is responsible for stimulation of "rest-and-digest" or "feed and breed" activities that occur when the body is at rest, especially after eating, including sexual arousal, salivation, lacrimation (tears), urination, digestion, and defecation. Its action is described as being complementary to that of the sympathetic nervous system, which is responsible for stimulating activities associated with the fight-or-flight response. Nerve fibres of the parasympathetic nervous system arise from the central nervous system. Specific nerves include several crani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gallbladder
In vertebrates, the gallbladder, also known as the cholecyst, is a small hollow organ where bile is stored and concentrated before it is released into the small intestine. In humans, the pear-shaped gallbladder lies beneath the liver, although the structure and position of the gallbladder can vary significantly among animal species. It receives and stores bile, produced by the liver, via the common hepatic duct, and releases it via the common bile duct into the duodenum, where the bile helps in the digestion of fats. The gallbladder can be affected by gallstones, formed by material that cannot be dissolved – usually cholesterol or bilirubin, a product of haemoglobin breakdown. These may cause significant pain, particularly in the upper-right corner of the abdomen, and are often treated with removal of the gallbladder (called a cholecystectomy). Cholecystitis, inflammation of the gallbladder, has a wide range of causes, including result from the impaction of gallstones, inf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bile Duct
A bile duct is any of a number of long tube-like structures that carry bile, and is present in most vertebrates. Bile is required for the digestion of food and is secreted by the liver into passages that carry bile toward the hepatic duct. It joins the cystic duct (carrying bile to and from the gallbladder) to form the common bile duct which then opens into the intestine. Structure The top half of the common bile duct is associated with the liver, while the bottom half of the common bile duct is associated with the pancreas, through which it passes on its way to the intestine. It opens into the part of the intestine called the duodenum via the ampulla of Vater. Segments The biliary tree (see below) is the whole network of various sized ducts branching through the liver. The path is as follows: Bile canaliculi → Canals of Hering → interlobular bile ducts → intrahepatic bile ducts → left and right hepatic ducts ''merge to form'' → common hepatic duct ''exits live ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphincter
A sphincter is a circular muscle that normally maintains constriction of a natural body passage or orifice and which relaxes as required by normal physiological functioning. Sphincters are found in many animals. There are over 60 types in the human body, some microscopically small, in particular the millions of precapillary sphincters. Sphincters relax at death, often releasing fluids and faeces. Functioning Each sphincter is associated with the lumen (opening) it surrounds. As long as the sphincter muscle is contracted, its length is shortened and the lumen is constricted (closed). Relaxation of the muscle causes it to lengthen, opening the lumen and allowing the passage of liquids, solids, or gases. This is evident, for example, in the blowholes of numerous marine mammals. Many sphincters are used every day in the normal course of digestion. For example, the lower oesophageal sphincter (or cardiac sphincter), which resides at the top of the stomach, is closed most of the time ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Hepatic Duct
The common hepatic duct is the first part of the biliary tract. It joins the cystic duct coming from the gallbladder to form the common bile duct. Structure The common hepatic duct is the first part of the biliary tract. It is formed by the convergence of the right hepatic duct (which drains bile from the right functional lobe of the liver) and the left hepatic duct (which drains bile from the left functional lobe of the liver). It then joins the cystic duct coming from the gallbladder to form the common bile duct. The duct is usually 6–8 cm long. The common hepatic duct is about 6 mm in diameter in adults, with some variation.Gray's Anatomy, 39th ed, p. 1228 The inner surface is covered in a simple columnar epithelium. Variation Around 1.7% of people have additional accessory hepatic ducts that join onto the common hepatic duct. Rarely, the common hepatic duct joins onto the gallbladder directly, leading to illness. Function The hepatic duct is part of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cystic Duct
The cystic duct is the short duct that joins the gallbladder to the common hepatic duct. It usually lies next to the cystic artery. It is of variable length. It contains 'spiral valves of Heister', which do not provide much resistance to the flow of bile. Function Bile can flow in both directions between the gallbladder and the common bile duct and the hepatic duct. In this way, bile is stored in the gallbladder in between meal times. The hormone cholecystokinin, when stimulated by a fatty meal, promotes bile secretion by increased production of hepatic bile, contraction of the gall bladder, and relaxation of the Sphincter of Oddi. Clinical significance Gallstones can enter and obstruct the cystic duct, preventing the flow of bile. The increased pressure in the gallbladder leads to swelling and pain. This pain, known as biliary colic, is sometimes referred to as a gallbladder "attack" because of its sudden onset. During a cholecystectomy, the cystic duct is clipped two or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nerve Plexus
A nerve plexus is a plexus (branching network) of intersecting nerves. A nerve plexus is composed of afferent and efferent fibers that arise from the merging of the anterior rami of spinal nerves and blood vessels. There are five spinal nerve plexuses, except in the thoracic region, as well as other forms of autonomic plexuses, many of which are a part of the enteric nervous system. The nerves that arise from the plexuses have both sensory and motor functions. These functions include muscle contraction, the maintenance of body coordination and control, and the reaction to sensations such as heat, cold, pain, and pressure. There are several plexuses in the body, including: *Spinal Plexuses ** Cervical plexus - serves the head, neck and shoulders **Brachial plexus - serves the chest, shoulders, arms and hands **Lumbosacral plexus ***Lumbar plexus - serves the back, abdomen, groin, thighs, knees, and calves **** Subsartorial plexus - below the sartorius muscle of thigh ***Sacral plex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superior Pancreaticoduodenal Artery
The superior pancreaticoduodenal artery is an artery that supplies blood to the duodenum and pancreas. Structure It is a branch of the gastroduodenal artery, which most commonly arises from the common hepatic artery of the celiac trunk, although there are numerous variations of the origin of the gastroduodenal artery. The pancreaticoduodenal artery divides into two branches as it descends, an anterior and posterior branch. These branches then travel around the head of the pancreas and duodenum, eventually joining with the anterior and posterior branches of the inferior pancreaticoduodenal artery. The inferior pancreaticoduodenal artery is a branch of the superior mesenteric artery. These arteries, together with the pancreatic branches of the splenic artery, form connections or anastomoses with one another, allowing blood to perfuse the pancreas and duodenum through multiple channels. The artery supplies the anterior and posterior sides of the duodenum and head of pancreas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
