| 释义 |
axon Anat.|ˈæksɒn|
Also axone, pl. axones.
[ad. Gr. ἄξων axis.]
†a. The body axis. Obs.
b. A filamentous process of a nerve cell carrying outgoing nerve impulses, usually single and often very long, in contrast to the multiple, branched, and short incoming fibres or dendrites: the essential constituent of most nerves. Hence aˈxonic a.
1842Dunglison Dict. Med. Sci. (ed. 3), Axon, axis. 1884Wilder in N.Y. Med. Jrnl. 2 Aug. 113 Axon, the mesal, longitudinal skeletal axis, represented in Branchiostoma and embryos by a membrano-gelatinous notochord. 1899L. Hill Human Physiol. xxix. 337 Each [nerve-]fibre consists of a soft central strand of protoplasmic substance called the axon or axis cylinder. 1902Encycl. Brit. XXV. 394/1 A neurone consists of three parts..(2) A single filament or axon, starting from the perikaryon. 1939Nature 23 Sept. 557/2 Such an axonic fusion is a most unusual feature in animals. 1940R. S. Woodworth Psychol. (ed. 12) viii. 250 Most nerve cells have two kinds of branches, a single axon and many dendrites.
▸ axon hillock n. a cone-shaped projection which links the body of a neuron to its axon and acts as a site for the generation of nerve impulses.
1899L. F. Barker Nerv. Syst. & Constituent Neurones x. 111 The axone itself..is entirely free from the stainable substance of Nissl, as is also the portion of the cell body immediately adjacent, known as the *axone hillock. 1934A. Forbes in C. Murchison Handbk. Gen. Exper. Psychol. i. iii. 189 We might then conceive of the formation of the mediator in the cell body and the initiation of the motor nerve impulse at the axon hillock. 1966Nature 3 Sept. 1102/2 The most striking electron microscopical feature of the axon hillock is the denseness of the surface... This effect is due to the close packing and alignment of neurofilaments. 1989B. Alberts et al. Molecular Biol. Cell (ed. 2) xix. 1088 The membrane of the axon hillock is where action potentials are initiated, and Na+ channels are plentiful there. |