Hepatic plexus | |
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Details | |
Identifiers | |
Latin | plexus hepaticus |
TA98 | A14.3.03.022 |
TA2 | 6697 |
FMA | 6632 |
Anatomical terms of neuroanatomy |
The hepatic plexus is a sympathetic and parasympathetic nerve plexus that provides innervation to the parenchyma of the liver as well as contributing innervation to some other abdominal structures.
Its sympathetic component is derived from the coeliac and superior mesenteric plexuses; its parasympathetic component is derived from the anterior and posterior vagal trunks.
The plexus receives post-ganglionic sympathetic afferents from the celiac plexus, [1] [2] and the superior mesenteric plexus. [1] The hepatic plexus is the largest derivative of the celiac plexus. [2]
The plexus receives pre-ganglionic parasymathetic afferents primarily [1] from the anterior vagal trunk, [1] [2] with a lesser contribution from [1] the posterior vagal trunk. [1] [2] The anterior vagal trunk issues one or more hepatic branches of anterior vagal trunk that pass in the superior portion of the lesser omentum to reach the hepatic plexus. [3] : 250–252
The plexus is the primary source of innervation for the parenchyma of the liver. Efferents of the plexus accompany the branches of the portal triad through the porta hepatis into the liver, ultimately reaching as far as the individual hepatocytes. [1]
Multiple fine branches arise from the plexus to be distributed to the gallbladder, and the extrahepatic bile ducts. [1]
Some accompany the gastroomental artery to provide a minor contribution to the innervation of the stomach. Some efferents from the plexus accompany the right gastric artery to reach and contribute to the innervation of the pylorus. Some accompany the gastroduodenal artery and its branches to reach the pylorus, proximal duodenum, and the pancreas. [1]
Other than their role in mediating vasoconstriction, the function of the plexus' efferents is unclear. [2] Efferents are apparently involved in regulating hepatic metabolism, and sinusoidal blood flow control. The plexus is however not functionally essential, as demonstrated by the continued functioning of transplanted livers where the efferents of the plexus are cut during the transplantation process. [1]
Efferents to the liver are involved in cholinergic, aminergic, peptidergic, and nitrergic neurotransmission. [1]
The parasympathetic component of the plexus' efferents to the gallbladder and extrahepatic bile duct is visceral motor and innervates the smooth muscle in the walls of the ducts and gallbladder. [1]
The vagus nerve, also known as the tenth cranial nerve, cranial nerve X, or simply CN X, is a cranial nerve that carries sensory fibers that create a pathway that interfaces with the parasympathetic control of the heart, lungs, and digestive tract. It comprises two nerves—the left and right vagus nerves—but they are typically referred to collectively as a single subsystem. The vagus is the longest nerve of the autonomic nervous system in the human body and comprises both sensory and motor fibers. The sensory fibers originate from neurons of the nodose ganglion, whereas the motor fibers come from neurons of the dorsal motor nucleus of the vagus and the nucleus ambiguus. The vagus was also historically called the pneumogastric nerve.
The duodenum is the first section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In mammals it may be the principal site for iron absorption. The duodenum precedes the jejunum and ileum and is the shortest part of the small intestine.
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 facial nerve, also known as the seventh cranial nerve, cranial nerve VII, or simply CN VII, is a cranial nerve that emerges from the pons of the brainstem, controls the muscles of facial expression, and functions in the conveyance of taste sensations from the anterior two-thirds of the tongue. The nerve typically travels from the pons through the facial canal in the temporal bone and exits the skull at the stylomastoid foramen. It arises from the brainstem from an area posterior to the cranial nerve VI and anterior to cranial nerve VIII.
Articles related to anatomy include:
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.
In human anatomy, the abdominal aorta is the largest artery in the abdominal cavity. As part of the aorta, it is a direct continuation of the descending aorta.
A nerve plexus is a plexus 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:
The hepatic artery proper is the artery that supplies the liver and gallbladder. It raises from the common hepatic artery, a branch of the celiac artery.
The cystic artery is (usually) a branch of the right hepatic artery that provides arterial supply to the gallbladder and contributes arterial supply to the extrahepatic bile ducts.
The midgut is the portion of the human embryo from which most of the intestines develop. After it bends around the superior mesenteric artery, it is called the "midgut loop". It comprises the portion of the alimentary canal from the end of the foregut at the opening of the bile duct to the hindgut, about two-thirds of the way through the transverse colon.
The celiac ganglia or coeliac ganglia are two large irregularly shaped masses of nerve tissue in the upper abdomen. Part of the sympathetic subdivision of the autonomic nervous system (ANS), the two celiac ganglia are the largest ganglia in the ANS, and they innervate most of the digestive tract.
The superior mesenteric plexus is a continuation of the lower part of the celiac plexus, receiving a branch from the junction of the right vagus nerve with the plexus.
The superior mesenteric ganglion is a ganglion in the upper part of the superior mesenteric plexus. It lies close to the origin of the superior mesenteric artery.
The esophageal plexus is formed by nerve fibers from two sources, branches of the vagus nerve, and visceral branches of the sympathetic trunk. The esophageal plexus and the cardiac plexus contain the same types of fibers and are both considered thoracic autonomic plexus.
The anterior vagal trunk is one of the two divisions into which the vagus nerve splits as it passes through the esophageal hiatus to enter the abdominal cavity. The anterior and posterior vagal trunks represent the inferior continuation of the esophageal nervous plexus inferior to the diaphragm. The majority of nerve fibres in the anterior vagal trunk are derived from the left vagus nerve.
In the circulatory system of vertebrates, a portal venous system occurs when a capillary bed pools into another capillary bed through veins, without first going through the heart. Both capillary beds and the blood vessels that connect them are considered part of the portal venous system.
The hepatic branches of anterior vagal trunk are branches of the anterior vagal trunk that provide parasympathetic innervation the liver, and gallbladder. Each anterior vagal trunk issues 1-2 hepatic branches which pass through the superior part of the omentum minus to reach and join the hepatic (nervous) plexus before proceeding to the porta hepatis. The anterior vagal trunk is the main source of parasymathetic afferents for the hepatic plexus.
The following outline is provided as an overview of and topical guide to human anatomy:
The cystic plexus is the derivation of the hepatic plexus, which is the largest offshoot from the celiac plexus.
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