Describe the pathway sperm are carried along to reach the exterior during sexual arousal. Which organs produce the fluids that make up semen? Are the excretory and reproductive systems fully separate in human males; in females? How is semen delivered into the female?
Tiny ducts carry the mature sperm from the tubules to the epididymis, a very coiled tube located on the surface of each testis. The epididymis stores the mature but, as yet, non-motile sperm. During sexual arousal, the epididymes produce secretions that carry the sperm into the two vasa deferentia or sperm ducts. Each vas deferens passes from its epididymis, through its inguinal canal, and over the bladder to join with the urethra immediately after the urethra arises from the bladder. Three sets of glands secrete fluids which combine with the sperm to form semen. The seminal vesicles meet the vasa deferentia just before their junction with the urethra. The prostate gland secretes into the urethra just after its junction with the sperm ducts. The Cowper's glands empty into the urethra as it reaches the base of the penis. The urethra passes through the penis and carries the semen to the outside. In human males, then, the urethra is used during both the excretory and reproductive processes. Only in females are the two processes carried out by two completely separate systems. During sexual arousal, the penis, a major source of sexual stimulation, becomes
