Pl. crura. [L. crūs, pl. crūra, leg.]
† 1. Geom. A straight line forming one side of a triangle. Obs. rare.
a. 1687. H. More, Antid. Ath., I. iv. Schol. (1712), 144. All the Crura’s, EG, EH, EI, EC, are easily demonstrated to be equal to the Crus E.
2. Anat. a. The leg or hind limb; spec. the part between the knee and the ankle, the shank. b. Applied to various parts occurring in pairs or sets and resembling or likened to legs.
Crura of the cerebellum, cerebrum, fornix, and medulla oblongata, strands of nerve-fibers in the brain; crura of the diaphragm, two tendinous and muscular bundles, one on each side, connecting the diaphragm with the lumbar vertebræ; crura of the penis, of the clitoris, bodies forming the attachments of those organs, one on each side of the pubic arch. Also applied to the two processes of the incus and those of the stapes (bones of the ear).
1727–51. Chambers, Cycl., Crus, among anatomists, denotes all that part of the body which reaches from the buttocks to the toes. Ibid., Crura of the medulla oblongata, are two of the four roots whence the medulla oblongata springs, in the brain.
1783. H. Watson, in Med. Commun., I. 186. The crura of the diaphragm … were removed.
1845. Todd & Bowman, Phys. Anat., I. 271. The central stem, or crus, around which each hemisphere of the cerebellum is developed.
