nerve

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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 ?
New Delhi: Sunrisers Hyderabad held their nerved to deny Delhi Daredevils their first win in Indian Premier League this season by clinching a last-over triumph at the Feroz Shah Kotla Stadium yesterday.
Lower glume 3-4 x 0.5-0.7 mm, slightly concave, lanceolate, chartaceous, margins glabrous, 2nerved, acute apex; upper glume 2.6-3.1 x 0.7-1 mm, chartaceous, margins glabrous, 3-nerved, the lateral nerves tenuous, acute apex.
32 cm long, ca..8 cm in diameter, green, white lanate; peduncle bracts ovate-lanceolate, acuminate and apiculate, erect, densely imbricate, 4.5-6 x 2.8-3 cm, exceeding the internodes, greenish or the upper ones reddish toward the apex and apical margins, nerved, sparsely white lanate near the base and at the apex to glabrescent, inconspicuously denticulate neat the apex to entire, the upper peduncle bracts involucrate and resembling the primary bracts.
After 10 minutes Marske settled any nerves with an excellent strike from Curtis Wood.
Inflorescences lateral, erect, paniculate; scape much longer than leaves, emerging from a bundle of bracts and sheaths resembling new rosette borne in the axils of leaves, cylindrical in cross section, 4-5(-10) mm in diameter, light to dark brown, glabrous basally, apically slightly white-lepidote, internodes (2-)4.5-5 cm long, basal bracts of the scape polystichous, narrowly triangular, acute and acuminate, 4.5-7 cm long, 1.4-1.6 cm wide, densely imbricate, conspicuously nerved, densely lepidote abaxially, margins laxly spinose, upper scape bracts polystichous, adpressed to the peduncle, narrowly triangular, acute and acuminate, 2-3.2(-5.5) cm long, 6-7(-9) mm wide, conspicuously lepidote abaxially, sparsely lepidote adaxially, strongly nerved, margins thin, laxly spinose.
The Transfiguration, in George Buttrick's words, "nerved the Early Church." Perhaps we could use some of that "nerving" in our time.
What was the object that nerved us, or those who went before us, to this choice?
NEIL Armstrong was a quiet, self-described "nerdy" engineer who became a global hero when as a steely nerved US pilot he made "one giant leap for mankind" with the first step on the Moon.
But this can also see you nerved up and if you don't pace yourself, you'll bang a shin or turn an ankle.
Peduncle 80-90 cm long, 0.4 cm wide, erect, exceeding the leaves, slightly lepidote; peduncle bracts the lower ones foliaceous, the upper ones 4-10 cm long, 1.5-2 cm wide, elliptic, attenuate and with a recurved apex, with hyaline margins, the lower ones imbricate, the upper ones exposing the peduncle, erect, slightly lepidote, nerved; Inflorescence: primary bracts ca.
Baloch said that Barrister Bhurgari was a strong- nerved man and he was never afraid of the British rulers who at times misbehaved with him also.
The operation involves the severing or removal of leg nerves running to the foot and can leave the horse unaware of any possible pain.