| 释义 |
distal, a.|ˈdɪstəl|
[f. stem of dist-ant + -al1, after dorsal, ventral, etc.]
Anat. Situated away from the centre of the body, or from the point of origin (said of the extremity or distant part of a limb or organ); terminal. Opp. to proximal.
1808J. Barclay Muscular Motions 415 The bones of the distal phalanx. 1814J. H. Wishart tr. Scarpa's Treat. Hernia p. xvi, Each pair of the extremities..have a proximal and a distal end; the former being that nearest the trunk, the latter that most remote. 1875Darwin Insectiv. Pl. x. 251 From the distal to the basal end of a leaf. 1881Mivart Cat 37 The paw is the distal part of a limb.
b. transf.
1882D. Hooper in Standard 10 Oct. 2/2 The drainage-pipes are..very imperfectly..connected at their proximal or house termination, although they must, by the Act, be well connected at their distal or main drain termination. 1885Klein Micro-organ. & Dis. (1886) 20 The distal end of the tube is introduced..into the neck of the sterilised flask. 1894Westm. Gaz. 20 June 3/2 The distal message can be reproduced type-written.
Add:c. Geol. Designating or characteristic of an area relatively far from a sedimentation zone, volcanic vent, or other region of geological activity, but close enough to have been influenced by it.
1949F. J. Pettijohn Sedimentary Rocks xiv. 444 The terms ‘proximal’, ‘axial’, or ‘distal’ may also be applied to the deposits according to their position in the trough of deposition. 1968Embleton & King Glacial & Periglacial Geomorphol. (1971) ix. 224 The features eroded by actively moving ice sheets are generally asymmetrical, having steeper proximal slopes than distal slopes. 1979Nature 25 Jan. 290/1 The greywackes grade from a proximal, quartz-rich, conglomeratic facies at the base, to a distal, finegrained, apparently volcaniclastic facies towards the top. 1985Thorpe & Brown Field Descr. Igneous Rocks v. 55 The distal zone (beyond ca. 5–15 km from the central vent, and extending beyond the volcano) is characterized by pyroclastic flow deposits. |