Pl. lumina. [L. = light; an opening.] An opening, passage or canal. a. Anat. and Zool. b. Bot. c. Surg. The passage of any tube in an instrument.
a. 1873. T. H. Green, Introd. Pathol. (ed. 2), 81. The vessel thus calcified, loses its … contractility; its lumen is diminished.
1888. Beddard, in Encycl. Brit., XXIV. 680/2. A longitudinal fold on the dorsal side which projects into the lumen of the intestine.
1893. Shipley, Zool. Invertebr., 214. In the lumen of the siphon is a small valve.
b. 1887. Garnsey & Balfour, trans. De Bary’s Fungi, 321. The hyphæ … usually have their walls thickened till the lumina disappear.
1900. Jackson, Gloss. Bot. Terms, Lumen, the space which is bounded by the walls of an organ, as the central cavity of a cell.
c. 1889. Lancet, 9 Nov., 949/1. Tracheotomy was resorted to, the larger lumen of the tube affording a freer vent. Ibid. (1894), 3 Nov., 1033. The lumen of the catheter.
