. The science and art of midwifery. Fig. 94.—Anterior half of the pelvis,. * As no two pelves possess piecisely the same dimensions, pelvic measurements aregiven somewhat differently by authors. They are obtained either by taking the mean ofa large number of pelves (a method which furnishes fractions difficult to remember, but MECHANISM OF LABOR. 157. The inferior or small pelvis comprises the portion below the lineafcerminalis. It is formed by the sacrum, the coccyx, the lower por-tion of the ilia, the ischia and pubes, the obturator membrane, andthe sacro-sciatic ligaments. Together the fore
. The science and art of midwifery. Fig. 94.—Anterior half of the pelvis,. * As no two pelves possess piecisely the same dimensions, pelvic measurements aregiven somewhat differently by authors. They are obtained either by taking the mean ofa large number of pelves (a method which furnishes fractions difficult to remember, but MECHANISM OF LABOR. 157. The inferior or small pelvis comprises the portion below the lineafcerminalis. It is formed by the sacrum, the coccyx, the lower por-tion of the ilia, the ischia and pubes, the obturator membrane, andthe sacro-sciatic ligaments. Together the foregoing inclose a basin-like cavity, which, though open below in the skeleton, is closed inby soft parts in the living subject. The posterior wall, formed bythe sacrum and coccyx, measures five inches in a direct line from thepromontory to the apex ; the anterior wall at the symphysis pubis mea-sures one and three quarters inch; the lateral walls, from the linea ter-minals to the tuberosities of the ischia, measure three and three quar-ters inches. The posterior wall is curved ; the symphysis pubis slopesdownward and inward, so asto run nearly parallel withthe two upper sacral vertebras;the rami of the pubes approachone another at an angle of 95°to 100° and unite beneath thesymphysis in the form of anarch, the arcus pubis ; the side-walls are
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Keywords: ., bookcentury1800, bookdecade1890, bookidsci, booksubjectobstetrics
