nerve


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Related to nerve: sciatic nerve, nerve pain

nerve:

see nervous systemnervous system,
network of specialized tissue that controls actions and reactions of the body and its adjustment to the environment. Virtually all members of the animal kingdom have at least a rudimentary nervous system.
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Nerve

 

the cordlike association of nerve tissues that links the brain and nerve ganglia by innervation to the other organs and tissues of the body.

A nerve primarily consists of nerve fibers. In vertebrates many nerves converge to form a bundle that is surrounded by a connective tissue sheath, the perineurium; the thin interstitial layers of connective tissue that separate the individual fibers deep within the bundle constitute the endoneurium. Finally, the entire nerve trunk, comprising several bundles, is covered by an additional sheath, the epineurium.

Nerves can be sensory (also called afferent or centripetal) or motor (also called efferent or centrifugal). Some nerves, for example, those innervating the skeletal muscles, mainly include myelinated, or medullated, fibers; others, for example, the sympathetic nerves, largely consist of unmyelinated, or unmedullated, fibers.

In reptiles, birds, mammals, and man 12 pairs of cranial nerves branch from the brain: the olfactory (cranial nerve I), the optic (cranial nerve II), the oculomotor (cranial nerve III), the trochlear (cranial nerve IV), the trigeminal (cranial nerve V), the abducent (cranial nerve VI), the facial (cranial nerve VII), the acoustic (cranial nerve VIII), the glossopharyngeal (cranial nerve IX), the vagus (cranial nerve X), the accessory (cranial nerve XI), and the hypoglossal (cranial nerve XII). Only the first ten pairs are present in fish and amphibians.

In man there are 31 pairs of spinal nerves: eight cervical, 12 thoracic, five lumbar, five sacral, and one coccygeal. Each pair innervates the effectors and receptors of a certain part of the body. The spinal nerves branch from the spinal cord into two roots—the posterior, or sensory, and the anterior, or motor. Both roots then combine to form a common trunk that consists of both sensory and motor fibers.

Several adjacent nerves can be combined into nerve plexuses, where an exchange of fibers between different nerves can take place. Three large plexuses are distinguished: the cervical, the brachial, and the lumbosacral. Each nerve plexus is the origin of several pairs of nerves; for example, the sacral portion of the lumbosacral plexus gives rise to the sciatic nerves.

Nerves that originate in the ganglia, trunks, and plexuses of the autonomic nervous system constitute a specific group. The optic nerve is remarkable for its large number of fibers; there are more than 1 million in the human optic nerve. Usually, however, there are 103 -104 fibers in a nerve. In invertebrates certain nerves are known to consist of only a few fibers. The peripheral nervous system in animals and man consists of aggregations of nerves.

D. A. SAKHAROV

nerve

[nərv]
(neuroscience)
A bundle of nerve fibers or processes held together by connective tissue.

nervure

Any one of the ribs of a groined vault, but esp. a rib which forms one of the sides of a compartment of the groining.

nerve

1. any of the cordlike bundles of fibres that conduct sensory or motor impulses between the brain or spinal cord and another part of the body
2. a large vein in a leaf
3. any of the veins of an insect's wing
References in periodicals archive ?
a) The distance from tibial nerve origin (at the end of the sciatic nerve) to its terminal division deep to the flexor retinaculum.
b) The diameter and thicknesses of tibial nerve in a site of the bifurcation, at popliteal fossa, and at the site of terminal division has been determined.
The nerve repair biomaterials market is further segmented into nerve conduits and, nerve grafts.
Nerve transfer is one of the important nerve injury treatment modalities to restore limb function.
The superficial location of the ulnar nerves facilitates their evaluation by High Resolution USG, and the nerve can be probed along its length in both static and dynamic states.
The report provides a detailed understanding of the nerve repair market.
The upper branch of 1st intercostobrachial nerve passed along the base of axilla, then left the axilla by passing through lower triangular space and finally joined with posterior cutaneous nerve of arm on each side whereas the lower branch passed along the base of axilla to reach the upper and medial part of arm where they join with medial cutaneous nerve of arm on each side.
Avance Nerve Graft is an off-the-shelf commercially available processed nerve allograft for bridging severed nerves without the comorbidities associated with a second surgical site.
As we continue our advanced research and development in the area of peripheral nerve repair for long gap nerve injuries, we are pleased to extend our existing product line to address an immediate clinical need in the area of neuroma formation at the terminal ends of injured nerves, "said ShuTung Li, Ph.
They were divided into two groups, group A included patients in whom dissection of recurrent laryngeal nerve was done as standard procedure while in group B, the nerve was not exposed.
A fascicle map of a compound nerve relates each fascicle to the distal nerve branch with which it exits and, therefore, to the distal muscles or organs innervated by that distal nerve branch (Figure 1).