390 



DISSECTION OF THE PELVIS. 



relations. 



Spongy. 



Fixed curve 

 of urethra : 



extent ; 



where 



greatest. 



Voluntary 

 and invo- 

 luntary 

 muscles 

 surround it. 



Contents of 

 the female 

 pelvis, 



and their 

 situation. 



The peri- 

 toneum on 

 the uterus ; 



the next portion of the urethral tube is directed backwards below 

 it, its under surface measures only half an inch. 



This portion of the urethra is the weakest ; but it is supported 

 by the triangular ligament (n). Surrounding it are the muscular 

 fibres of the constrictor urethrae ; and close behind it are Cowper's 

 glands and the rectum. 



The spongy part (d) is so named from its being surrounded by a 

 cellulo- vascular structure. It is applied to and assists to form the 

 body of the penis, and the canal terminates anteriorly in the orifice 

 named the meatus urinarius at the end of the glans. It is the longest 

 part of the urethra, and measures about six inches. At its com- 

 mencement this division of the excretory canal is covered by the 

 ejaculator urinae muscle. 



The fixed curve of the urethra is the bend at the hinder part of 

 the canal as it lies behind the pubis. It extends from the bladder 

 to an inch and a half in front of the aperture in the triangular 

 ligament, and comprises the prostatic and membranous portions, 

 with a fourth of the spongy part. Its convexity, which is turned 

 downwards and backwards, is greatest immediately below the 

 triangular ligament in the erect posture of the body ; and from this 

 point it ascends to the bladder, but is directed nearly horizontally 

 forwards to the penis. 



It is surrounded by voluntary and involuntary muscular fibres ; 

 thus, above the ligament, by the involuntary muscular tissue of the 

 prostate ; within the ligament by the voluntary constrictor urethras, 

 with a thin involuntary layer inside that muscle ; and below the 

 ligament by the voluntary ejaculator urinae. 



The size of the canal is least where the tube lies between the layers 

 of the ligament, except at the external urinary meatus ; and it is 

 largest in the middle of the prostate. 



RELATIONS OF THE VISCERA IN THE FEMALE. 



In the pelvis of the female are contained the rectum and the 

 bladder, with the ureters and urethra, as in the male ; but there 

 are in addition the uterus with its accessories, and the vagina. 



Position. The rectum is posterior to the rest as in the male pelvis, 

 and forms a like curve. In the concavity of the bent intestine lie 

 the uterus with its appendages, and the tube of the vagina. And 

 in front of all are the bladder and the urethra. There are thus 

 three tubes connected with the viscera in this sex, viz., the urethra, 

 the vagina, and the rectum ; and all are directed downwards to the 

 surface. 



THE PERITONEUM. The student should first master the descrip- 

 tion of the peritoneum of the pelvic cavity contained on pages 

 376 to 378. 



In addition to what has already been described it will be noticed 

 that whilst the peritoneum covers the whole of the back of the 

 uterus it only passes some two-thirds of the way down its anterior 

 surface and is then reflected on to the upper surface of the bladder 

 without again touching the vagina. 



