164 THE PELVIS AND THE GENITAL ORGANS. 



take part of the weight from the abdominal walls, 

 while the true pelvis, being more surrounded by 

 bone and so capable of affording more protection, 

 guards the internal organs of generation. The lower 

 circumference of the pelvis is known as the outlet. In 

 the female the bones are lighter, the sacrum less curved, 

 and the diameters greater than in the male. 



On the whole, the pelvic bones are well covered in with 

 muscles. The anterior superior spine, however, is easily 

 felt in front and the whole crest can be felt back to the 

 posterior superior spine. The tuberosity of the ischium 

 also can be felt, especially when the thigh is flexed, 

 for it is largely uncovered of muscles. The spine of 

 the os pubis can always be felt, on a level with the great 

 trochanter, and the relation of its position to that of 

 a hernia shows whether the rupture is above or below 

 Poupart's ligament, that is, whether it is inguinal or 

 femoral. 



Occasionally there is lack of development of the pubic 

 bones for two or three inches and the bladder is exposed. 

 Fracture of the pelvis may occur, perhaps with injury 

 to the viscera. The acetabulum may be fractured 

 or the sacrum broken, with injury to the sacral plexus 

 of nerves, causing paralysis of the lower extremities 

 and of the sphincters, with resultant involuntary pas- 

 sage of urine and feces, and in childbirth the coccyx 

 is often broken. In rickets there may be great deform- 

 ity of the pelvis, causing trouble in childbirth later in 

 life. Osteomalacia is a disease of adults, in which the 

 bones are soft and the weight pushes the promontory 

 of the sacrum forward and approximates the sides of 

 the pelvis. 



The Male Generative Organs. The male generative 

 organs consist of the prostate gland, testes, and penis. 



The prostate gland is shaped like a small horse-chest- 

 nut and is composed of numerous glands from which 

 come a dozen or more excretory ducts. It surrounds 

 the neck of the bladder and the beginning of the urethra 



