Volume 1

Elements of anatomy / / edited by William Sharpey, Allen Thomson, and Edward Albert Schafer.

  • Jones Quain
Date:
1878
Catalogue details

Licence: Public Domain Mark

Credit: Elements of anatomy / / edited by William Sharpey, Allen Thomson, and Edward Albert Schafer. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

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    verte])ra,' thence it is again gradually contracted as far as the last dorsal, and becomes suddenly much greater in the lumbar region. In a lateral view the antero-posterior diameter of the bodies increases in descending through the dorsal and lumbar regions. Viewed from behind the spines occupy the middle line. On each side are the vertebral grooves, corresponding to the laminae, and bounded externally in the cervical and dorsal regions by the transverse processes, and in the lumbar by the mammillary pro- cesses. Along each groove is a series of spaces between the laminae, which, in the natural condition, are filled up by the yellow ligaments. The extent of these intervals is very trifling in the neck and in the greater part of the back ; it increases in the lower third of the dorsal, and still more in the lumbar region. The interval be- tween the occipital bone and the arch of the atlas is considerable, and so is that between the last lumbar vertebra and the sacrum. Fig. 16.—The Vertebral Column viewed from THE Left Side. (A. T.) | The letters and numbers indicate the several vertebrte. The antero-posterior curvatures of the column are shown, togetlier with tl]o shajje and size of the bodies and intervertebral spaces, the form and transitions of the transverse and spinous processes, and the differences in the costal articulating surfaces. OSSIFICATION OF THE VEBTEBRiS. The Vertebrse in general.—The ossifi- cation of each vertebra proceeds in cartilage from three principal centres, one for the main part of the body, and one on each side for the arch and processes, together with a part on each side of the body. The lateral centres appear about the 7th week, that of the body very soon afterwards. From these centres the ossification extends gradu- ally outwards, so as at last to form the greater part of the vertebra. That of the body does not pass, however, in the dorsal vei-tebras, the place of articulation of the head of the rib, leaving on each side a portion of the body which is formed from the lateral centre, c 2