URINARY BLADDER. 533 



to its summit, whence it is guided to the anterior wall of the abdomen by 

 the umbilical ligaments and urachus. The muscular coat consists of two 



Fig. 234. 



ffit 



layers, an external layer composed of longitudinal fibres, the detrusor 

 urinse ; and an internal layer of oblique and transverse fibres irregularly 

 distributed. The anterior longitudinal fibres commence by four tendons 

 (the tendons of the bladder or of the detrusor urinse), two superior from 

 the ossa pubis, and two inferior from the rami of the ischia, and spread 

 out as they ascend upon the anterior surface of the bladder to its fundus ; 

 they then converge upon the posterior surface of the organ,.and descend 

 to its neck, where they are inserted into the isthmus of the prostate gland, 

 and into a ring of muscular tissue, which surrounds the commencement 

 of the prostatic portion of the urethra. Some of the anterior fibres are 

 also attached to this ring. The lateral fibres commence at the prostate 

 gland and the muscular ring of the urethra on one side, and spread out as 

 they ascend upon the side of the bladder to descend upon the opposite 

 side, and be inserted into the prostate and opposite segment of the same 

 ring. Two bands of oblique fibres are described by Sir Charles Bell, as 



*A side view of the viscera of the male pelvis, in situ. The right side of the pelvis 

 has been removed by a vertical section made through the os pubis near the symphysis ; 

 and another through the middle of the sacrum. 1. The divided surface of the os pubis. 

 2. The divided surface of the sacrum. 3. The body of the bladder. 4. Its fundus; from 

 the apex is seen passing upwards the urachus. 5. The base of the bladder. 6. The 

 ureter. 7. The neck of the bladder. 8, 8. The pelvic fascia; the fibres immediately 

 above 7 are given off from the pelvic fascia, and represent the anterior ligaments of the 

 bladder. 9. The prostate gland. 10. The membranous portion of the urethra, between 

 the two layers of the deep perineal fascia. 11. The deep perineal fascia formed of two 

 layers. 12. One of Cowper's glands between the two layers of deep perineal fascia, and 

 beneath the membranous portion of the urethra. 13. The bulb of the corpus spongiosum. 

 14. The body of the corpus spongiosum. 15. The right crus penis. 16. The upper part 

 of the first portion of the rectum. 17. The recto-vesical fold of peritoneum. 18. The 

 second portion of the rectum. 19. The right vesicula seminalis. 20. The vas deferens 

 21. The rectum covered by the descending layer of the pelvic fascia, just as it is making 

 its bend backwards to constitute the third portion. 22. A part of the levator am muscle 

 investing the lower part of the rectum. 23. The external sphincter ani. 24. The in- 

 terval between the deep and superficial perineal fascia: they are seen to be continuous 

 beneath the number. 

 45* 



