PELVIS FEMUR. 89 



more solid, and the cavity deeper and narrower. In the female the 

 bones are lighter and more delicate, the iliac fossae are large and 

 the ilia projecting ; the inlet, and the outlet, and the cavity are 

 large, and the acetabula farther removed from each other; the 

 cavity is shallow, the tuberosities widely separated the obturator 

 foramina triangular, and the arch of the pubis wide. The precise 

 diameter of the inlet and outlet, and the depth of the cavity, are 

 very important considerations to the accoucheur. 



The diameters* of the inlet or brim are three; 1, Antero-pos- 

 terior, sacro-pubic or conjugate ; 2, transverse ; and 3, oblique. 

 The antero-posteriar extends from the symphysis pubis to the middle 

 of the promontory of the sacrum, and measures four inches and a 

 half. The transverse extends from the middle of the brim on one 

 side to the same point on the opposite, and measures five inches and 

 a quarter. The oblique extends from the sacro-iliac symphysis on 

 one side, to the margin of the brim corresponding with the aceta- 

 bulum on the opposite, and measures five inches and one-eighth. 



The diameters of the outlet are two, antero-posterior, and trans- 

 verse. The antero-posterior diameter extends from the lower part 

 of the symphysis pubis, to the apex of the coccyx ; and the trans- 

 verse from the first part of one tuberosity to the same point on the 

 opposite side ; they both measure four inches. The cavity of the 

 pelvis measures in depth four inches and a half, posteriorly ; three 

 inches and a half in the middle ; and one and a half at the sym- 

 physis pubis. 



FEMUR. The femur is a long bone, divisible, like other bones of 

 the same class, into a shaft, a superior and an inferior extremity. 



At the superior extremity is a rounded head, directed upwards and 

 inwards, and marked just below its centre by an oval depression for 

 the ligamentum teres. The head is supported by a neck, which 

 varies in length and obliquity at various periods of life, being long 

 and oblique in the adult short and almost horizontal in the aged. 

 Externally to the neck is a large process, the trochanter major, 

 which presents upon its anterior surface an oval facet, for the 

 attachment of the tendon of the gluteus minimus muscle ; and above, 

 a double facet, for the insertion of the gluteus medius. On its poste- 

 rior side is a vertical ridge the linea quadrati, for the attachment 

 of the quadratus femoris muscle. Upon the inner side of the tro- 

 chanter major is a deep pit, trochanteric or digital fossa, in which 

 are inserted the tendons of the pyriformis, gemellus superior and 

 inferior, and obturator externus and internus muscles. Passing 

 downwards from the trochanter major in front of the bone is an 

 oblique ridge, which forms the inferior boundary of the neck, the 

 anterior intertrochanteric line ; and behind, another oblique ridge, 

 the posterior intertrochanteric line, which terminates in a rounded 



* These diameters are quoted from an excellent " Manual of Practical Midwifery," 

 by Dr. James Reid. 



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