(redirected from nervy)
Also found in: Dictionary, Thesaurus, Medical, Legal, Idioms.
Related to nervy: easy mark, unconquerable


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.
..... Click the link for more information.



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.



A bundle of nerve fibers or processes held together by connective tissue.


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.


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 ?
Firth and Strong play it commendably straight, making it hard to work out which - if either - is the villain and Kidman is on top form as the nervy, spiky woman walking a psychological tightrope.
They (Loovens and Majstorovic) made a nervy start," he said.
Guardiola's side took a while to find their rhythm in a nervy opening quarter of an hour.
Having won a nervy opening set the Russian lost her serve at 4-3 when the finishing line was in sight and was eventually pushed all the way by the unfancied Australian.
I had chatted with Feld a week or so earlier, and he seemed his usual wary, nervy, witty, charming, prickly, unsettled, unsettling self.
That was badly received by nervy investors, who have been bruised by WorldCom and Enron.
Ding's team theorizes that prehistoric people who trekked from Africa to distant locales may have relied on nervy, intrepid individuals to lead the journey.
Despite the superior results achieved compared to more conventional extruders when processing most compounds, the extrusion of others, typically nervy natural rubber, has posed more of a challenge.
Fuksas' fragment of city is a nervy restless landscape in which there is nothing symmetrical and everything is calculated to promote the dynamic.
What a rich set of ingredients for a fresh, nervy post-cold War thriller.
Murray (left), who turned 27, overcame a few nervy moments to beat tricky left-hander Jurgen Melzer 7-6 6-4 and move through to the quarter-finals of the Rome Masters.
And Rodgers expects the fight "to go right to the wire" and knows from experience a strong start for his side will ensure a nervy time at the Etihad.