Читать книгу Mother, Nurse and Infant - S. P. Sackett - Страница 17

The sacrum (Fig. 1) terminates the vertebral column, and is perhaps the most important bone in the pelvis, obstetrically considered, as it enters largely into the various deformities of the pelvis. In the adult it is of a triangular shape, the base of the triangle being above and inclining forwards, the apex below and somewhat backwards; its length is from four to four and a half inches; its breadth about four inches, and the greatest thickness, two and a half inches. The internal surface is concave to the amount of half an inch, crossed by four transverse lines, marking the former division by cartilage; here are four pair of holes, through which pass numerous nervous filaments, which afterwards form part of the great sciatic nerve.

Fig. 1–	A	represents the internal or anterior surface of the sacrum.
	B B	represents the articular processes.
	C C	represents the anterior sacral foramen.
	D	represents the articulating surface.

It is placed at the posterior part of the pelvis, where it appears like a wedge forced in between the ossa innominata, immediately below the vertebral column and directly above the coccyx.