1068 SURGICAL ANATOMY OF THE PERINEUM. 



The Prostate Gland is a pale, firm, glandular body which is placed immediately 

 below the neck of the bladder, around the commencement of the urethra. It is 

 placed in the pelvic cavity, behind the lower part of the symphysis pubis, above 

 the deep layer of the triangular ligament, and rests upon the rectum, through 

 which it maybe distinctly felt, especially when enlarged. In shape and size it 

 resembles a chestnut. Its base is directed upward toward the neck of the bladder. 

 Its apex is directed downward to the deeper layer of the triangular ligament, 

 which it touches. 



Its posterior surface is smooth, marked by a slight longitudinal furrow, and rests 

 on the second part of the rectum, to which it is connected by areolar tissue. Its 

 anterior surface is flattened, marked by a slight longitudinal furrow, and placed 

 about three-quarters of an inch below the pubic symphysis. It measures about 

 an inch and a half in its transverse diameter at the base, an inch in its antero- 

 posterior diameter, and three-quarters of an inch in depth. Hence the greatest 

 extent of incision that can be made in it Avithout dividing its substance completely 

 across is obliquely backward and outward. This is the direction in which the 

 incision is made in it in the lateral operation of lithotomy. 



Artery of corpus cavernosum. 

 Dorsal artery of penis 



Artery of bulb. 

 Internal pudic artery.. 



Cowper's gland. 



FIG. 593. A view of the position of the viscera at the outlet of the pelvis. 



Above the prostate a small triangular portion of the bladder is seen, bounded, 

 in front and below, by the prostate gland ; above, by the recto-vesical fold of the 

 peritoneum ; on each side, by the vesicula seminalis and the vas deferens. It is 

 separated from direct contact with the rectum by the recto-vesical fascia. The 

 relation of this portion of the bladder to the rectum is of extreme interest to the 

 surgeon. In cases of retention of urine this portion of the organ is found pro- 

 jecting into the rectum, between three and four inches from the margin of the 

 anus, and may be easily perforated without injury to any important parts: this 

 portion of the bladder is, consequently, occasionally selected for the performance 

 of the operation of tapping the bladder. 



Surgical Anatomy. The student should consider the position of the various parts in refer- 

 ence to the lateral operation of lithotomy. This operation is performed on the left side of the peri- 

 nseum, as it is most convenient for the right hand of the operator. A grooved staff having been 



