A nerve plexus is a

plexus In neuroanatomy, a plexus (from the Latin term for "braid") is a branching network of vessels or nerves. The vessels may be blood vessels (veins, capillaries) or lymphatic vessels. The nerves are typically axons outside the central nervous syste ...

(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 A spinal nerve is a mixed nerve, which carries motor, sensory, and autonomic signals between the spinal cord and the body. In the human body there are 31 pairs of spinal nerves, one on each side of the vertebral column. These are grouped into th ...

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 enteric nervous system (ENS) or intrinsic nervous system is one of the main divisions of the autonomic nervous system (ANS) and consists of a mesh-like system of neurons that governs the function of the gastrointestinal tract. It is capable of ...

. 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 The brachial plexus is a network () of nerves formed by the anterior rami of the lower four cervical nerves and first thoracic nerve ( C5, C6, C7, C8, and T1). This plexus extends from the spinal cord, through the cervicoaxillary canal in t ...

- serves the chest, shoulders, arms and hands **

Lumbosacral plexus The anterior divisions of the lumbar nerves, sacral nerve A spinal nerve is a mixed nerve, which carries motor, sensory, and autonomic signals between the spinal cord and the body. In the human body there are 31 pairs of spinal nerves, one on ...

***

Lumbar plexus The lumbar plexus is a web of nerves (a nervous plexus) in the lumbar region of the body which forms part of the larger lumbosacral plexus. It is formed by the Ventral ramus of spinal nerve, divisions of the first four lumbar nerves (L1-L4) and ...

- serves the back, abdomen, groin, thighs, knees, and calves **** Subsartorial plexus - below the sartorius muscle of thigh ***

Sacral plexus In human anatomy, the sacral plexus is a nerve plexus which provides motor and sensory nerves for the posterior thigh, most of the lower leg and foot, and part of the pelvis. It is part of the lumbosacral plexus and emerges from the lumbar verte ...

- serves the pelvis, buttocks, genitals, thighs, calves, and feet *** Pudendal plexus **

Coccygeal plexus The coccygeal plexus is a nerve plexus near the coccyx bone. Structure This plexus is formed by the ventral rami The ventral ramus (pl. ''rami'') (Latin for ''branch'') is the anterior division of a spinal nerve. The ventral rami supply the ant ...

- serves a small region over the coccyx *Autonomic Plexuses **

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 abdomi ...

(solar plexus) - serves internal organs ** Auerbach's plexus (myenteric plexus) - serves the gastrointestinal tract **

Meissner's plexus The submucosal plexus (Meissner's plexus, plexus of the submucosa, plexus submucosus) lies in the submucosa of the intestinal wall. The nerves of this plexus are derived from the myenteric plexus which itself is derived from the plexuses of parasy ...

(submucosal plexus) - serves the gastrointestinal tract **

Pharyngeal plexus of vagus nerve The pharyngeal plexus is a network of nerve fibers innervating most of the palate and pharynx. (The larynx, which is innervated by the superior and recurrent laryngeal nerves from vagus nerve (CN X), is not included.) It is located on the surf ...

- serves the palate and pharynx **

Cardiac plexus The cardiac plexus is a plexus of nerves situated at the base of the heart that innervates the heart. Structure The cardiac plexus is divided into a superficial part, which lies in the concavity of the aortic arch, and a deep part, between the ao ...

- serves the heart

Spinal plexuses

The following table shows the nerves that arise from each spinal plexus as well as the spinal level each plexus arises from.

Cervical plexus

The Cervical plexus is formed by the ventral rami of the upper four cervical nerves and the upper part of fifth cervical ventral ramus. The network of rami is located deep to the sternocleidomastoid within the neck. The cervical plexus innervates muscles of the neck and areas of skin on the head, neck and chest. The deep branches innervate muscles, while the superficial branches supply areas of skin. A long branch (primarily of fibers of C4 and with contributions of fibers from C3 and C5; nervus phrenicus) innervates muscles of the diaphragm. The cervical plexus also communicates with the cranial nerves

vagus nerve The vagus nerve, also known as the tenth cranial nerve, cranial nerve X, or simply CN X, is a cranial nerve that interfaces with the parasympathetic control of the heart, lungs, and digestive tract. It comprises two nerves—the left and righ ...

and

hypoglossal nerve The hypoglossal nerve, also known as the twelfth cranial nerve, cranial nerve XII, or simply CN XII, is a cranial nerve that innervates all the extrinsic and intrinsic muscles of the tongue except for the palatoglossus, which is innervated by ...

Brachial plexus

The

is formed by the ventral rami of C5-C8-T1 spinal nerves, and lower and upper halves of C4 and T2 spinal nerves. The plexus extends toward the armpit. The ventral rami of C5 and C6 form upper trunk, the ventral ramus of C7 forms the middle trunk, and the ventral rami of C8 and T1 join to form the lower trunk of the brachial plexus. Under the clavicle, the trunks reorganize to form cords ''(fasciculi)'' around the

axillary artery In human anatomy, the axillary artery is a large blood vessel that conveys oxygenated blood to the lateral aspect of the thorax, the axilla (armpit) and the upper limb. Its origin is at the lateral margin of the first rib, before which it is c ...

''(arteria axillaris)''. The lateral cord ''(fasciculus lateralis)'' is formed by the upper and middle trunk, all three trunks join to form the posterior cord ''(fasciculus posterior)'', the lower trunk continues to the medial trunk ''(fasciculus medialis)''. The

nerves A nerve is an enclosed, cable-like bundle of nerve fibers (called axons) in the peripheral nervous system. A nerve transmits electrical impulses. It is the basic unit of the peripheral nervous system. A nerve provides a common pathway for the e ...

(containing

motor An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy. Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power g ...

and sensory fibers) to the

shoulder The human shoulder is made up of three bones: the clavicle (collarbone), the scapula (shoulder blade), and the humerus (upper arm bone) as well as associated muscles, ligaments and tendons. The articulations between the bones of the shoulder mak ...

and to the

upper limb The upper limbs or upper extremities are the forelimbs of an upright-postured tetrapod vertebrate, extending from the scapulae and clavicles down to and including the digits, including all the musculatures and ligaments involved with the shou ...

emerge from the brachial plexus.

Lumbar plexus

Since the

and

are interconnected, they are sometimes referred to as the

. The intercostal nerves that give rami to the chest and to the upper parts of the abdominal wall efferent

innervation and to the

pleura The pulmonary pleurae (''sing.'' pleura) are the two opposing layers of serous membrane overlying the lungs and the inside of the surrounding chest walls. The inner pleura, called the visceral pleura, covers the surface of each lung and dips b ...

and

peritoneum The peritoneum is the serous membrane forming the lining of the abdominal cavity or coelom in amniotes and some invertebrates, such as annelids. It covers most of the intra-abdominal (or coelomic) organs, and is composed of a layer of meso ...

afferent sensory innervation are the only ones that do not originate from a plexus. The ventral rami of L1-L5 spinal nerves with a contribution of T12 form Lumbar plexus. This plexus lies within the

psoas major muscle The psoas major ( or ; from grc, ψόᾱ, psóā, muscles of the loins) is a long fusiform muscle located in the lateral lumbar region between the vertebral column and the brim of the lesser pelvis. It joins the iliacus muscle to form the il ...

. Nervi of the plexus serve the skin and the muscles of the lower

abdominal wall In anatomy, the abdominal wall represents the boundaries of the abdominal cavity. The abdominal wall is split into the anterolateral and posterior walls. There is a common set of layers covering and forming all the walls: the deepest being the ...

, the

thigh In human anatomy, the thigh is the area between the hip ( pelvis) and the knee. Anatomically, it is part of the lower limb. The single bone in the thigh is called the femur. This bone is very thick and strong (due to the high proportion of ...

and external genitals. The largest nerve of the plexus is the

femoral nerve The femoral nerve is a nerve in the thigh that supplies skin on the upper thigh and inner leg, and the muscles that extend the knee. Structure The femoral nerve is the major nerve supplying the anterior compartment of the thigh. It is the largest ...

. It supplies anterior muscles of the thigh and a part of skin distal to the inguinal ligament.

Sacral plexus

Ventral rami of L4-S3 with parts of L4 and S4 spinal nerves form the

. It is located on the posterior wall of

pelvic cavity The pelvic cavity is a body cavity that is bounded by the bones of the pelvis. Its oblique roof is the pelvic inlet (the superior opening of the pelvis). Its lower boundary is the pelvic floor. The pelvic cavity primarily contains the reproduc ...

(pelvis minor). Nervi of the plexus innervate the perineal region,

buttocks The buttocks (singular: buttock) are two rounded portions of the exterior anatomy of most mammals, located on the posterior of the pelvic region. In humans, the buttocks are located between the lower back and the perineum. They are composed ...

and the

lower limb The human leg, in the general word sense, is the entire lower limb of the human body, including the foot, thigh or sometimes even the hip or gluteal region. However, the definition in human anatomy refers only to the section of the lower limb ex ...

. The largest nerve of the human body, the sciatic nerve, is the main branch that gives rami to the

innervation of the

muscles Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of musc ...

of the

, the

leg A leg is a weight-bearing and locomotive anatomical structure, usually having a columnar shape. During locomotion, legs function as "extensible struts". The combination of movements at all joints can be modeled as a single, linear element ca ...

, and the foot. Common peroneal nerve and its branches innervate some parts of the skin of the foot, the peroneal muscles of the leg, and the dorsal muscles of the foot.

Coccygeal plexus

originates from the ventral rami of spinal nerves S4, S5, and Co. It is interconnected with the lower part of

. The only nerve of the plexus is the

coccygeal nerve A spinal nerve is a mixed nerve, which carries motor, sensory, and autonomic signals between the spinal cord and the body. In the human body there are 31 pairs of spinal nerves, one on each side of the vertebral column. These are grouped into the ...

, that serves sensory innervation of the skin in the coccygeal region.

Autonomic plexuses

Autonomic plexuses can contain both sympathetic and parasympathetic neurons. The

cardiac plexus The cardiac plexus is a plexus of nerves situated at the base of the heart that innervates the heart. Structure The cardiac plexus is divided into a superficial part, which lies in the concavity of the aortic arch, and a deep part, between the ao ...

is located near the aortic arch and the carina of the trachea. The

pulmonary plexus The pulmonary plexus is an autonomic plexus formed from pulmonary branches of vagus nerve and the sympathetic trunk. The plexus is in continuity with the deep cardiac plexus. Structure It innervates the bronchial tree and the visceral pleura. ...

supplies innervation to the bronchial tree. The celiac, or

solar 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 abdo ...

, is located around the celiac trunk and contains the celiac ganglia. The solar plexus is the largest autonomic plexus and provides innervation to multiple abdominal and pelvic organs. The

superior mesenteric plexus 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. It surrounds the superior mesenteric artery, accompanies it into the mesentery, ...

includes the superior mesenteric ganglia and is located around the superior mesenteric artery. The

inferior mesenteric plexus The inferior mesenteric plexus is derived chiefly from the aortic plexus. It surrounds the inferior mesenteric artery, and divides into a number of secondary plexuses, which are distributed to all the parts supplied by the artery, viz., the left ...

includes the inferior mesenteric ganglia and is located around the inferior mesenteric artery. Together, these plexuses innervate the intestines. Some other plexuses include the superior and

inferior hypogastric plexus The inferior hypogastric plexus (pelvic plexus in some texts) is a network () of nerves that supplies the organs of the pelvic cavity. The inferior hypogastric plexus gives rise to the prostatic plexus in males and the uterovaginal plexus in female ...

renal plexus The renal plexus is a complex network of nerves formed by filaments from the celiac ganglia and plexus, aorticorenal ganglia, lower thoracic splanchnic nerves and first lumbar splanchnic nerve and aortic plexus. The nerves from these sources ...

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 o ...

splenic plexus The splenic plexus (lienal plexus in older texts) is formed by branches from the celiac plexus, the left celiac ganglion, and from the right vagus nerve. It accompanies the lienal artery to the spleen The spleen is an organ found in almost ...

gastric plexus The superior gastric plexus (gastric or coronary plexus) accompanies the left gastric artery along the lesser curvature of the stomach, and joins with branches from the left vagus nerve. The term "inferior gastric plexus" is sometimes used to desc ...

pancreatic plexus In human neuroanatomy, the pancreatic plexus is a division of the 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 ...

, and

testicular plexus The spermatic plexus (or testicular plexus) is derived from the renal plexus, receiving branches from the aortic plexus. It accompanies the internal spermatic artery to the testis A testicle or testis (plural testes) is the male reproductive ...

ovarian plexus The ovarian plexus arises from the renal plexus, and is distributed to the ovary, and fundus of the uterus. It is carried in the suspensory ligament of the ovary.Johannes Sobotta: Sobotta Atlas of Human Anatomy I-II. (Urban & Schwarzenberg, München 1982) * Saladin, Kenneth S. ''Anatomy & Physiology: The Unity of Form and Function''. New York, NY: McGraw-Hill, 2007. Print.

References

Instant Anatomy, 2010, webpage

External links

* *{{MerckHome, 06, 095, d - Plexus disorders Peripheral nervous system