hypotonic, a.
(haɪpəˈtɒnɪk)
[f. hypo- 4 + tonic a.]
1. a. Physiol. Of a solution: having a lower osmotic pressure than some particular solution (usually that in a cell, or a bodily fluid). Const. to.
| 1895 Jrnl. Physiol. XVIII. 114 The passage of a salt from a hypotonic fluid into the blood-plasma. 1946 Nature 9 Nov. 665/2 The fluid obtained in this way was hypotonic to the cœlomic fluid. 1951 H. Davson Textbk. Gen. Physiol. vii. 163 If the plasma surrounding the cells is steadily diluted (i.e., made hypotonic), the latter increase in volume until they finally burst. 1970 [see hypertonic a. 2]. |
b. Ophthalm. Of the eye: having a reduced intra-ocular pressure.
| 1918 R. H. Elliot Glaucoma: Textbk. for Student ii. 19 The case of a hypotonic eye (with a Schiötz reading corresponding to a tension of 8 to 15 mm. of Hg.) such as may be met with after a trephining or other sclerectomy operation. 1966 S. Lerman Basic Ophthalm. iv. 246 A hypotonic eye indicates that a leaking wound may be present. |
2. Med. Exhibiting or characterized by diminished tone or tension (in muscle or muscular tissue).
| 1904 [see hypertonus 2]. 1908 Practitioner Oct. 560 The lower extremities have been thin, powerless, and extraordinarily hypotonic. 1966 [see hypertonic a. 1]. |