Special anatomy and histology: in two volumes (Volume 1).

  • Horner, William E. (William Edmonds), 1793-1853.
Date:
1851
Catalogue details

Licence: Public Domain Mark

Credit: Special anatomy and histology: in two volumes (Volume 1). Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    The texture of the os innominatum is cellular within, with a con- densed lamella externally. It is of very various thickness. The ilium, in its centre, has the dorsal or the external and the ventral or internal sides so near one another, that in most adults the light will shine through them. A large foramen is seen on the venter of the ilium, and another on its dorsum, for the transmission of nutritious arteries. There are several others, smaller, at various points of the os innominatum, for the same purpose, and for the adhesion of ligamentous fibres. SECT. V.—OF THE PELVIS GENERALLY. The sacrum and coccyx behind, and the ossa innominata at the sides and in front, constitute, as observed, the whole cavity called pelvis (bassin). Its position is such, that, in the adult, it divides the entire length of the body into two parts nearly equal, the head and trunk forming one part, and the lower extremities the other. Generally, the former are somewhat the longer; but in cases of unusual corporeal stature, the excess depends upon an undue length of the inferior ex- tremities. On the contrary, in persons of little height, the latter have not been developed in proportion to the trunk of the body. The pelvis, as a whole, is a conoidal cavity, having its base upwards, and the summit below. Its internal surface forms an irregular floor, on which the viscera of the abdomen are sustained in the erect posi- tion; and its external surface, by projecting considerably at various places, establishes very favorable points for the attachment of mus- cles. The internal surface of the pelvis is divided by the projection of the anterior margin of the base of the sacrum, and by the linea ilio-pectinea, into two cavities; the upper one is the great pelvis, and the lower one the lesser pelvis. The great pelvis is the base of the cone, and presents at its anterior part a large deficiency, which is supplied in the fresh subject by the abdominal muscles. The lesser pelvis is a complete bony canal, much deeper behind and at the sides than in front. Its depth, behind, is formed by the whole length of the sacrum and coccyx; at the sides by the bodies of the ischia and a small part of the ilia; and, in front, only by the length of the bodies of the pubes. The upper orifice of the lesser pelvis is called the superior strait; it is somewhat oval, and looks obliquely forwards and upwards. Its axis may be indicated by a line drawn from the extremity of the coccyx to a point an inch, or thereabouts, below the umbilicus. The inferior orifice of the lesser pelvis is called the inferior strait. Its margins in the naked skeleton are very unequal, for it presents three very deep notches, two lateral, and one in front. The first are formed by the external margins of the sacrum and coccyx, contributing to deepen the sciatic notch, which already is formed in each innominatum. The third one is formed by the convergence of the rami of the pubes and ischia of the opposite sides, and constitutes the arch of the pelvis of authors, sometimes called the arch of the pubes. The axis of the lower strait, it is clear, must have a very different direction from the axis of the superior, and is indicated by a line drawn from the lower part of