| 释义 |
hypertonic, a.|haɪpəˈtɒnɪk|
[f. hyper- 5 + tonic a.]
1. Med. Exhibiting or characterized by excessive tone or tension (in muscle or muscular tissue).
1855R. G. Mayne Expos. Lex. Med. Sci. (1860) 484/1 Hypertonicus, of or belonging to hypertonia: hypertonic. 1886Lancet 13 Mar. 486/2 For convenience I describe the group of symptoms under the term ‘hyper-tonic paresis’, a symptomatic nomenclature which commits to no theory. 1907W. Russell Arterial Hypertonus i. 3 The degree of contraction may exceed the limits of normal variation, and when it does the term hypertonic contraction, or merely arterial contraction, will be used here. 1933W. R. Brain Dis. Nervous Syst. i. 8 Immediately following a capsular haemorrhage the paralysed limbs are completely flaccid... After a variable interval..tone gradually returns to the affected muscles and they ultimately become hypertonic or ‘spastic’. 1966McGraw-Hill Encycl. Sci. & Technol. X. 528/1 When the stretch reflex is absent, the muscle is hypotonic or flaccid; when stretch reflexes are exaggerated..the muscles are hypertonic or spastic.
2. Physiol. Of a solution: having a higher osmotic pressure than some particular solution (usually that in a cell, or a bodily fluid). Const. to.
1895Jrnl. Physiol. XVIII. 107 None of the water is taken up from hypertonic or isotonic solutions. 1936A. P. Mathews Princ. Biochem. xxxiv. 364 If the solution have an osmotic pressure greater than that of the blood, it is said to be hypertonic to the blood. 1951Whitby & Hynes Med. Bacteriol. (ed. 5) vi. 73 The optimum salt concentration is usually near the range of isotonicity to body cells; markedly hypertonic saline diminishes the reaction. 1970A. F. Brading in E. Bülbring et al. Smooth Muscle vi. 172 Tissues will swell in hypotonic solutions, and shrink in hypertonic ones. |