| axon reflex | An effect brought about by the passage of the nerve impulses from a sensory ending to the effector organ along divisions of the nerve fibre without traversing a synapse, e.g., as in the vasodilation resulting from stimulation of the skin or the irritation of the conjunctiva; the reaction occurs even when the nerve fibre has been sectioned and thus isolated from the nervous centres. (05 Mar 2000) |
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| axon terminals | The somewhat enlarged, often club-shaped endings by which axons make synaptic contacts with other nerve cells or with effector cells (muscle or gland cells). As isolated, by homogenizing brain or spinal cord, they contain acetylcholine and the related enzymes. Terminals contain neurotransmitters of various kinds, sometimes more than one. These can be demonstrated by chemical analysis and immunocytochemical methods. See: synapse. Synonym: axonal terminal boutons, end-feet, neuropodia, pieds terminaux, synaptic boutons, synaptic endings, synaptic terminals, terminal boutons, bouton terminaux. (05 Mar 2000) |
| axonal | Pertaining to an axon. (05 Mar 2000) |
| axonal degeneration | A type of peripheral nerve fibre response to insult, wherein axon death and subsequent breakdown occurs, with secondary breakdown of the myelin sheath associated; caused by focal injury to peripheral nerve fibres; often referred to as wallerian degeneration. Synonym: axon degeneration. (05 Mar 2000) |
| axonal guidance | <cell biology> General term for mechanisms that ensure correct projections by nerve cells in developing and regenerating nervous systems. Implies accurate navigation by growth cones, the highly motile tips of growing neuronal processes. See: growth cone collapse. (12 Mar 1998) |
| axonal polyneuropathy | A type of polyneuropathy in which axon degeneration is the sole/predominant feature; many aetiologies, particularly toxic and metabolic; on nerve conduction studies, affects amplitudes of the responses, but does not cause conduction slowing or block. Synonym: axonal polyneuropathy. (05 Mar 2000) |
| axonal process | An obsolete term for axon. (05 Mar 2000) |
| axonal terminal boutons | The somewhat enlarged, often club-shaped endings by which axons make synaptic contacts with other nerve cells or with effector cells (muscle or gland cells). As isolated, by homogenizing brain or spinal cord, they contain acetylcholine and the related enzymes. Terminals contain neurotransmitters of various kinds, sometimes more than one. These can be demonstrated by chemical analysis and immunocytochemical methods. See: synapse. Synonym: axonal terminal boutons, end-feet, neuropodia, pieds terminaux, synaptic boutons, synaptic endings, synaptic terminals, terminal boutons, bouton terminaux. (05 Mar 2000) |
| axonal transport | Directed transport of organelles and molecules along a nerve cell axon. Transport can be anterograde (from the cell body) or retrograde (toward the cell body). (alberts et al., molecular biology of the cell, 3d ed, pg3) (12 Dec 1998) |
| axoneme | <cell biology> The central microtubule complex of eukaryotic cilia and flagella with the characteristic 9 + 2 arrangement of tubules when seen in cross-section. (12 Mar 1998) |
| axonin | <protein> Chick homologue of TAG 1. (18 Nov 1997) |
| axonogenesis | <cell biology> The growth and differentiation of axonal processes by developing neurons. See: axon. (12 Mar 1998) |
| axonography | The recording of electrical changes in axons. Synonym: electroaxonography. (05 Mar 2000) |
| axonopathy | A disorder affecting primarily the axons of peripheral nerve fibres, (although secondary demyelination occurs) in contrast to one that affects only myelin (myelinopathy). (05 Mar 2000) |
| axonotmesis | Interruption of the axons of a nerve followed by complete degeneration of the peripheral segment, without severance of the supporting structure of the nerve; such a lesion may result from pinching, crushing, or prolonged pressure. See: neurapraxia, neurotmesis. Origin: axon + G. Tmesis, a cutting (05 Mar 2000) |