Editing Human sexuality (section)

=====Internal male anatomy=====

Male internal reproductive structures are the testicles, the duct system, the prostate and seminal vesicles, and the [[bulbourethral gland|Cowper's gland]].<ref name="ReferenceA"/>{{page needed|date=February 2016}}

The testicles (male gonads), are where sperm and male hormones are produced. Millions of sperm are produced daily in several hundred seminiferous tubules. Cells called the [[Leydig cell]]s lie between the tubules; these produce hormones called androgens; these consist of [[testosterone]] and [[inhibin]]. The testicles are held by the spermatic cord, which is a tubelike structure containing blood vessels, nerves, the vas deferens, and a muscle that helps to raise and lower the testicles in response to temperature changes and sexual arousal, in which the testicles are drawn closer to the body.<ref name="ReferenceA"/>{{page needed|date=February 2016}}

Sperm gets transported through a four-part duct system. The first part of this system is the [[epididymis]]. The testicles converge to form the [[seminiferous tubules]], coiled tubes at the top and back of each testicle. The second part of the duct system is the [[vas deferens]], a muscular tube that begins at the lower end of the epididymis.<ref name="ReferenceA"/>{{page needed|date=February 2016}} The vas deferens passes upward along the side of the testicles to become part of the spermatic cord.<ref name="ReferenceB"/> The expanded end is the ampulla, which stores sperm before ejaculation. The third part of the duct system is the ejaculatory ducts, which are {{convert|1|in|cm|abbr=out|adj=on}}-long paired tubes that pass through the prostate gland, where semen is produced.<ref name="ReferenceA"/>{{page needed|date=February 2016}} The prostate gland is a solid, chestnut-shaped organ that surrounds the first part of the urethra, which carries urine and semen.<ref name="ReferenceA"/>{{page needed|date=February 2016}}<ref name="ReferenceB"/> Similar to the female G-spot, the prostate provides sexual stimulation and can lead to [[orgasm]] through [[anal sex]].<ref name="Rosenthal">{{cite book |first=Martha |last= Rosenthal| title = Human Sexuality: From Cells to Society | publisher =[[Cengage Learning]]|year = 2012|pages=133–135| isbn = 978-0-618-75571-4|url =https://books.google.com/books?id=d58z5hgQ2gsC&pg=PT153}}</ref>

The prostate gland and the seminal vesicles produce seminal fluid that is mixed with sperm to create semen.<ref name="ReferenceA"/>{{page needed|date=February 2016}} The prostate gland lies under the bladder and in front of the rectum. It consists of two [[Portal:Main|main]] zones: the inner zone that produces secretions to keep the lining of the male urethra moist and the outer zone that produces seminal fluids to facilitate the passage of semen.<ref name="ReferenceB"/> The seminal vesicles secrete fructose for sperm activation and mobilization, prostaglandins to cause uterine contractions that aid movement through the uterus, and bases that help neutralize the acidity of the vagina. The Cowper's glands, or bulbourethral glands, are two pea-sized structures beneath the prostate.