| 释义 |
phasic, a.|ˈfeɪzɪk, -sɪk|
[f. Gr. ϕάσ-ις phase n. + -ic.]
1. Of, pertaining to, or of the nature of a phase or phases; presenting phases.
1890Chamb. Jrnl. 13 Sept. 588/2 It is not..the mere phasic change of the moon that influences the weather. 1898Allbutt's Syst. Med. V. 417 The number [of lymphocytes] in the blood undergoes phasic variation. 1947Sci. News V. 24 Gjessing concluded that the phasic disturbance of nitrogen metabolism constituted the fundamental pathology of the disorder, the mental changes being merely the outward symptoms. 1975Nature 6 Nov. 81/1 Action potential firing of individual endocrine cells falls into two principal categories: most fire continuously and randomly at 1–2 spikes s-1, while the rest have a phasic pattern of firing, periods of bursting activity alternating over 10–60 s with periods of silence.
2. Physiol. Responding to a change in environment, rather than to a constant stimulus.
1906C. S. Sherrington Integrative Action Nervous Syst. viii. 302 The very muscles that to the observer are most obviously under excitation by the tonic system are those most obviously inhibited by the phasic reflex system. 1956Jrnl. Physiol. CXXXIV. 48 A temperature receptor..has..a high coefficient of phasic discharge to temperature change or a high coefficient of tonic discharge to maintained temperatures. 1973Sci. Amer. May 97/1 Many human receptors, such as the ones that sense pressure on the skin, are phasic; if they were not, one would be constantly conscious of such things as a wristwatch or a shirt.
Hence ˈphasically adv.
1975Nature 6 Nov. 81/1 We found that, during bilateral occlusion of the common carotid arteries, supraoptic neurones are excited and that this activation is confined almost exclusively to phasically active neurones. |