On the mechanical structure of the cancellous tissue of bone / by W.W. Wagstaffe.

  • Wagstaffe, W. W. (William Warwick), 1843-1910.
Date:
1875
Catalogue details

Licence: Public Domain Mark

Credit: On the mechanical structure of the cancellous tissue of bone / by W.W. Wagstaffe. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    nating vertically to both anterior and posterior articular surfaces. These curves are parabolic. A similar section in the middle line (Fig. 10) shows a curiously different construction. In the lower end of the shaft the old arrangement exists, but the articular portion which is here nearly circular, shows curved fibres springing from the lamina between the two fossae, and curving back- wards and forwards respectively to the posterior and anterior aspects, so as to terminate at right angles to these surfaces. Other fibres are placed more or less concentrically with the outline of the section. These simple and beautiful arrangements are admirably adapted to protect the bone from concussion in every position of this exposed and constantly used joint. Ulna.—The shape of this bone being peculiar and evidently intended for special mechanical purposes, the arrangement of its internal structure becomes of considerable importance. In a vertical section of the upper end from before backwards (Fig. 11), we are able to see that the same principle is carried Fia. n. Ulna.—Plan of construction seen in vertical section through great sigmoid cavity and olecranon. Fig. 12. Ulna.—Section of upper end from side to side. out as in other bones already noticed, that it is built up essentially of curved columns more and more diverging, and that the uppermost of these are concered in the support of pressure at the joint surface. Those springing from the front wall of the shaft receive the pressure which occurs when the arm is extended as in striking “from the shoulder,” or in