- Nerve plexus
A nerve plexus is a network of intersecting nerves. Except for the ventral rami of Th2-Th11 nerves, they combine sets of ventral rami of spinal nerves that serve the same area of the body into one large grouped nerve. There are several in the body, including:
- Cervical plexus - serves the head, neck and shoulders
- Brachial plexus - serves the chest, shoulders, arms and hands
- Lumbar plexus - serves the back, abdomen, groin, thighs, knees, and calves
- Sacral plexus - serves the pelvis, buttocks, genitals, thighs, calves, and feet
- Solar plexus - serves internal organs
- Coccygeal plexus - serves a small region over the coccyx
- Auerbach's plexus - serves gastrointestinal tract
The Cervical plexus (plexus cervicalis) 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 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 (C4; nervus phrenicus) innervates muscles of the diaphragm. Communications with cranial nerves vagus nerve [X.] and hypoglossal nerve [IX.] (nervus vagus et nervus hypoglossus) exist.
The Brachial plexus (plexus brachialis) 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 (axilla). The roots of C5 and C6 form upper trunk (truncus superior), the ramus C7 forms the middle trunk (truncus medius), and the rami C8 and T1 join to form the lower trunk (tuncus inferior) of the brachial plexus. Under the clavicle, the trunks (trunci) reorganize to form cords (fasciculi) around the axillary artery (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 peripheral nerves (motor and sensory fibers) to the shoulder and to the upper limb emerge from the brachial plexus.
Since the Lumbar plexus and Sacral plexus are interconnected, they are sometimes referred to as the Lumbosacral plexus. The intercostal nerves that give rami to the chest and to the upper parts of the abdominal wall efferent motor innervation and to the pleura and peritoneum 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. Nervi of the plexus serve the skin and the muscles of the lower abdominal wall, the tight and external genitals. The largest nerve of the plexus is the femoral nerve. It supplies anterior muscles of the tight and a part of skin distal to the inguinal ligament.
Ventral rami of L4-S3 with parts of L4 and S4 spinal nerves form the Sacral plexus. It is located on the posterior wall of pelvic cavity (pelvis minor). Nervi of the plexus innervate the perineal region, buttocks and the lower limb. The largest nerve of the human body, the sciatic nerve is the main branch, that give rami to the motor innervation of the muscles of the foot, the leg and the thigh. Common peroneal nerve and its branches innervate some part of the skin of the foot, the peroneal muscles of the leg and the dorsal muscles of the foot.
Coccygeal plexus originate from S4, S5, Co1 spinal nerves. (It is interconnected with the lower part of Sacral plexus). The only nerve of the plexus is the coccygeal nerve, that serves sensory innervation of the skin in the coccygeal region.
- Autonomic plexuses
- Autonomic nervous system
- Solar (celiac) plexus
- Auerbach's plexus
- Meissner's plexus
- Henry Gray: Anatomy of the human body (Bartleby.com; Great Books Online)
- Richard S. Snell: Clinical neuroanatomy (Lippincott Williams & Wilkins, Ed.6th 2006) Philadelphia, Baltimore, New York, London. ISBN 978 963 226 293 2
- Eldra P. Solomon - Richard R. Schmidt - Peter J. Adragna : Human anatomy & physiology ed. 2nd 1990 (Sunders College Publishing, Philadelphia) ISBN 0 03 011914 6
- Jochen Staubesand (Ed.); R. Putz, R. Pabst, Johannes Sobotta: Sobotta Atlas of Human Anatomy I-II. (Urban & Schwarzenberg, München 1982) ISBN 3-541-72710-1
- Instant Anatomy, 2010, webpage: 
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Look at other dictionaries:
nerve plexus — noun a network of intersecting nerves • Hypernyms: ↑plexus, ↑rete • Hyponyms: ↑autonomic plexus, ↑plexus autonomici, ↑brachial plexus, ↑plexus brachialis, ↑cardiac plexus … Useful english dictionary
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abdominal nerve plexus — noun a large plexus of sympathetic nerves in the abdomen behind the stomach • Syn: ↑solar plexus, ↑coeliac plexus, ↑plexus celiacus • Hypernyms: ↑nerve plexus • Part Holonyms: ↑sympathetic nervous system … Useful english dictionary
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plexus aorticus thoracalis — plexus aorticus thoracicus [TA] thoracic aortic plexus: a nerve plexus around the thoracic aorta formed by filaments from the sympathetic trunks and vagus nerves, and from which fine twigs accompany branches of the aorta. It is continuous below… … Medical dictionary
Plexus — A plexus is a network. It has more specific meanings in multiple fields.BiologyIn biology it has multiple meanings.Nervous systemIn many animals the processes of neurons join together to form a plexus or nerve net. In vertebratesIn vertebrates, a … Wikipedia
plexus celiacus — noun a large plexus of sympathetic nerves in the abdomen behind the stomach • Syn: ↑solar plexus, ↑coeliac plexus, ↑abdominal nerve plexus • Hypernyms: ↑nerve plexus • Part Holonyms: ↑sympathetic nervous system … Useful english dictionary
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plexus pulmonalis — [TA] a nerve plexus formed by several strong trunks of the vagus nerve that are joined at the root of the lung by branches from the sympathetic trunk and cardiac plexus. The plexus is often described as having anterior and posterior parts (see… … Medical dictionary