| 释义 |
sternum Anat. and Zool.|ˈstɜːnəm|
Pl. sterna or sternums. See also sternon.
[mod.L., ad. Gr. στέρνον chest, breast. Cf. F. sternum.]
1. The breast-bone; a long bone or series of bones, occurring in most vertebrates except snakes and fishes, extending along the middle line of the front or ventral aspect of the trunk, usually articulating with some of the ribs, and with them completing the wall of the thorax.
Occasionally applied to the plastron of a turtle.
1667Phil. Trans. II. 544 Thrust it in about an Inch, directing the end of it toward the Sternum. 1681Grew Musæum i. §2. iii. 43 The fore part of the Sternum [of a Crocodile] is plainly bony. 1793T. Beddoes Lett. to Darwin 48 She had very acute pain under the sternum. 1801[C. Stewart] Elem. Nat. Hist. I. 272 Testudo..3. The land species..; shell convex, joined to the sternum with bony commissures. 1831R. Knox Cloquet's Anat. 27 The Sternum is composed of three bones placed one above another. These bones are in the adult most commonly joined together. 1890Coues Ornithol. 211 The Avian Sternum..is highly specialised; its extensive development is peculiar to the class of birds.
2. In Arthropoda: The ventral part of the body, or more usually of each somite or segment of the body (= sternite); opp. to tergum.
1835J. Duncan Beetles (Nat. Lib.) 107 The inferior portion of the thorax is composed of a single piece named the sternum, or breastbone. It is much developed in certain tribes, particularly water-beetles. 1881Packard Zool. (ed. 3) 329 These parts are respectively called tergite, pleurite, and sternite, while the upper region of the body is called the tergum, the lateral the pleurum, and the ventral or under portion the sternum. 1887C. L. Morgan Anim. Biol. 263 Ten terga and nine sterna can be made out in the male [cockroach]. |