DISSECTING MANUAL. 



posteriorly by deep grooves. The lateral surfaces are convex 

 and meet anteriorly in a rounded border (anterior surface). 

 The posterior surface is triangular and flattened and lies on 

 the rectum, separated from it by pelvic fascia. The apex lies 

 on the triangular ligament. [1173] 



The urethra, entering near the middle of the upper surface, 

 runs through the prostate, in a curve which is concave forward 

 and nearer the posterior surface than the anterior border; it 

 emerges at a point on the anterior border just above and in 

 front of the apex. The common ejaculatory ducts enter the 

 edge between the base and posterior surface, and descend to 

 the prostatic part of the urethra. The part between these ducts 

 and the urethra is the middle lobe, which projects against the 

 bladder just behind the urethra! orifice; the rest of the body 

 forms two lateral lobes. [1174] 



Structure. Unstriped muscle fibres constitute the greater 

 bulk, forming the outer layers and sending processes inward 

 through the glandular tissue; posteriorly some fibres are con- 

 tinuous with the bladder. The glandular tissue is practically 

 confined to the region behind the urethra; its ducts (about 

 twenty) chiefly open in a groove on each side of the crista 

 urethralis, on the posterior wall of the urethra. [1175] 



Cowper's Glands. These are two small glands, the size of 

 a pea; they lie under the membranous urethra between the 

 layers of the triangular ligament, between the apex of the pros- 

 tate and the bulb of the corpus spongiosum. Their ducts pierce 

 the bulb and open into the spongy urethra. [1176] 



Male Urethra. This is about eight inches long and runs 

 from the bladder to the meatus urinarius; it is divided into 

 three portions, prostatic, membranous, and spongy. The pros- 

 tatic portion is about an inch long and descends through the 

 prostate in a slight curve, concave forward, from base to apex. 

 Its posterior wall (floor) presents a mesial ridge (crista ure- 

 thrae, or verumontanum) which projects forward and extends 

 downward to the membranous urethra and upward to (some- 



[240] 



