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Related to Nerve terminal: synaptic cleft, Synaptic knob


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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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 ?
Interestingly, this VGCC subtype exchange occurs specifically in the nerve terminal, with no change in the cell body.
The proposed NO-based mechanism of ACR-induced synaptotoxicity therefore lacks nerve terminal specificity.
Nerve terminal sprouting in botulim type A treated mouse levator auris longus muscle.
Other observed changes in the same muscle had been associated with morphologic alterations of nerve terminal motor of the neuromuscular junction of G muscle [15].
Second, asynchronous conduction increases due to an immature motor nerve terminal and neuromuscular junction following denervation-reinnervation; thus, the duration of excitatory signal propagation from muscle fibers to the recording needle significantly varied, allowing more waveform spikes to be obtained.
Suzuki et al (2) suggested that a gradual decrease in the amount of transmitter released from the presynaptic nerve terminals during TOF stimulation was the explanation for the delayed recovery of the TOF ratio, despite no delay in T1 recovery, although in their study, the duration of the operation and the supplemental doses of vecuronium and mepivacaine given were not detailed (2).
Acetylcholinesterase is an enzyme in vertebrates that is responsible for breaking down acetylcholine into choline and acetic acid at the nerve terminal.
The tests--colonic motility study, anorectal manometry, defecography, electromyography and pudendal nerve terminal motor latency--serve to differentiate a pelvic outlet obstruction, which is the problem in a majority of patients, from colonic inertia.
After the MPTP attack, the dopamine-producing neurons still alive start to branch out, sending more fibers to the striatum, the area of the brain where the nerve terminal releases its precious cargo of dopamine.
Co-founder and Chairman of KineMed's Scientific Advisory Board and Chaired Professor at both UCSF Medical School and UC Berkeley, remarked that "It is exciting that two linked biochemical pathways -- the assembly-disassembly cycle of MTs in neurons and the MT-mediated transport of proteins along axons to the nerve terminal -- could be promising new therapeutic targets for neurodegenerative diseases.
At the time when an electrical impulse from one cell reaches a nerve terminal, Syt IV triggers the release of calcium.
A third pattern, damage to neuritic projections, produces a decrement in the membrane/total protein ratio in the nerve terminal region but an increase in areas where reactive sprouting takes place (Kostrzewa and Jacobowitz 1974; Navarro et al.