A treatise on the science and practice of midwifery / By W. S. Playfair.
- William Smoult Playfair
- Date:
- 1885
Licence: Public Domain Mark
Credit: A treatise on the science and practice of midwifery / By W. S. Playfair. Source: Wellcome Collection.
Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.
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![times, in accordance with the position of the body. During pregnancy especially, the obliquity of the brim is lessened by the patient throwing herself backward in order to support more easily the weight of the gravid uterus. The height of the promontory of the sacrum above the upper margin of the symphysis pubis is on an average about 3| inches, and a line passing horizontally backward from the latter point would impinge on the junction of the second and third coccygeal bones. Axes of the Parturient Canal.—By the axis of the pelvis is meant an imaginary line which indicates the direction which the foetus takes during its expulsion. The axis of the brim (Fig. 10) is a line drawn perpendicular to its plane, which would extend from the umbilicus to about the apex of the coccyx; the axis of the outlet of the bony pelvis intersects this, and extends from the centre of the promontory of the sacrum to midway between the tuberosities of the ischia. The axis of the entire pelvic canal is represented by the sum of the axes of an indef- inite number of planes at different levels of the pelvic cavity, which forms an irregular parabolic line, as represented in the diagram (Fig. 10, A d). Fig U. Representing General Axis of Parturient Canal, including the Uterine Cavity and Soft Parts. It must 1)6 borne in mind, however, that it is not tlic axis of the bony pelvis alone that is of iinj>()i'tMiH'c in obstetrics. We must always, in considering this subject, remember that the general axis of the parturient canal (Fig. 11) also includes that of the uterine cavity above and of the soft ])arts below. These are variable in direction ac(!ording to circum- stances; and it is only the axis of that portion of tlic parturient canal extending between the plane of the pelvic bi'im and a plane between the](https://iiif.wellcomecollection.org/image/b2121072x_0053.jp2/full/800%2C/0/default.jpg)
