| UN | ulnar nerve; undernourished; unilateral neglect; urea nitrogen; urinary nitrogen |
|---|---|
| UNCV | ulnar nerve conduction velocity |
| nerve block anaesthesia | Conduction anaesthesia in which local anaesthetic solution is injected about nerves, nerve trunks, or nerve plexuses. (05 Mar 2000) |
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| nerve cell | An excitable cell specialised for the transmission of electrical signals over long distances. Neurons receive input from sensory cells or other neurons and send output to muscles or other neurons. Neurons with sensory input are called sensory neurons, neurons with muscle outputs are called motoneurons, neurons that connect only with other neurons are called interneurons. Neurons connect with each other via synapses. Neurons can be the longest cells known, a single axon can be several metres in length. Although signals are usually sent via action potentials, some neurons are nonspiking. (18 Nov 1997) |
| nerve cell body | The part of the neuron that includes the nucleus but excludes the processes. (05 Mar 2000) |
| nerve compression syndromes | Repeated or prolonged pressure on a nerve root or peripheral nerve leading to ischemia, the response to which is oedema above and below the source of pressure. If the pressure is not relieved, fibrosis tends to develop. Types of nerve compression syndromes are the neuropathy caused by intervertebral disk herniation, compression of the median nerve in the carpal tunnel, compression of the ulnar nerve in the elbow, and compression of the lateral cutaneous nerve of the thigh in meralgia paresthetica. This is also called pressure neuropathy. (12 Dec 1998) |
| nerve conduction | The transmission of an impulse along a nerve fibre. (05 Mar 2000) |
| nerve conduction velocity | The rate of impulse conduction in a peripheral nerve or its various component fibres, generally expressed in meters per second. (05 Mar 2000) |
| nerve deafness | Neural deafness, former terms for sensorineural deafness. (05 Mar 2000) |
| nerve decompression | Release of pressure on a nerve trunk by the surgical excision of constricting bands or widening of a bony canal. (05 Mar 2000) |
| nerve degeneration | Loss of functional activity and trophic degeneration of nerve axons and their terminal arborizations following the destruction of their cells of origin or interruption of their continuity with these cells. The pathology is characteristic of neurodegenerative diseases. Often the process of nerve degeneration is studied in research on neuroanatomical localization and correlation of the neurophysiology of neural pathways. (12 Dec 1998) |
| nerve, efferent | A nerve that carries impulses away from the central nervous system. The word efferent comes from the latin ex', away or out + ferre , to bear = to bear out or carry away. (12 Dec 1998) |
| nerve endings | Specialised terminations of peripheral neurons. Nerve endings include neuroeffector junction(s) by which neurons activate target organs and sensory receptors (see receptors, sensory) which transduce information from the various sensory modalities and send it centrally in the nervous system. Presynaptic nerve endings are presynaptic terminals. (12 Dec 1998) |
| nerve fascicle | A bundle of nerve fibres surrounded by perineurium. (05 Mar 2000) |
| nerve fibre | The axon of a nerve cell, ensheathed by oligodendroglia cells in brain and spinal cord, and by Schwann cells in peripheral nerves. (05 Mar 2000) |
| nerve fibres | Slender processes of neurons, especially the prolonged axons that conduct nerve impulses. (12 Dec 1998) |
| nerve fibres, myelinated | Grayish white nerve fibres whose axons are encased in a myelin sheath which may in turn be enclosed by a neurilemma (a thin membrane spirally enwrapping the myelin layers). (12 Dec 1998) |