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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![Difference in the Two Sexes.—There is a very marlved difference between the pelvis in the male and the female, and the peculiarities of the latter all tend to facilitate the process of parturition. In the female pelvis (Fig. 5) all the bones are lighter in structure, and have the points for muscular attachments much less developed. The iliac bones are more spread out, hence the greater breadth which is observed in the female figure, and the peculiar side-to-side movement which all females have in walking. The tuberosities of the ischia are lighter in structure and farther apart, and the rami of the pubes also converge at a much less acute angle. This greater breadth of the pubic arch gives one of the most easily appreciable points of contrast between the male and the female pelvis; the pubic arch in the female forms an angle of from 90° to 100°, while in the male (Fig. 6) it averages from 70° to 75°. The obturator foramina are more triangular in shape. The whole cavity of the female pelvis is wider and less funnel-shaped than in the male, the symphysis pubis is not so deep, and, as the promon- tory of the sacrum does not project so much, the shape of the pelvic brim is more oval than heart-shaped. These differences between the male and female pelvis are probably due to the presence of the female Ficx. 7. Brim of Pelvis, showing Antero-posterior, Oblique, and Conjugate Diameters. genital organs in the true pelvis, the groM^th of which increases its development in Avidth. In proof of this, Schroeder states that in women with congenitally defective internal organs, and in women who have had both ovaries removed early in life, the pelvis has always more or less of the masculine type. Measurements of the Pelvis.—The measurements of the pelvis that are of most importance from an obstetric point of view are taken between various points directly ojijiosite to ea(;h other, and arc known as the fJiarneters of the pelvis. Those of the true jx'lvis are the diameters which it is cs])ecially important to fix in our memories, and it is cus- tomary to describe tlu^ee in Avorks on obstetrics—the antero-posterior or conjugate, the oblif)ne, and the transverse—although of ccjurse the meas- urements may be taken at any o[iposing ])oints in the circumference of the bones. The antero-posterior (sacro-|)iibic), at the brim (Fig. 7), is taken](https://iiif.wellcomecollection.org/image/b2121072x_0049.jp2/full/800%2C/0/default.jpg)
