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Male Reproductive System

The Male Reproductive System Channel answers your questions about parts of the male anatomy and how they function. Learn how the different parts of the male reproductive system work in this section.

What a Drop in Male Dog Fertility May Say About Human Male Fertility

A study showed a decline in male dog fertility over 26 years, which researchers think may be due to chemicals in the environment. See more »

Attention, Men: Live to 100, With One Horrible Trade-off

Study shows longevity is increased by castration. See more »

Do men hit their sexual peak in their 20s?

A long-held belief about sexuality is that men hit their sexual peak in their 20s. Does it all go downhill from there? Don't panic, guys -- you have biology on your side. See more »

Do new fathers have lower testosterone than single men?

Superficially, men's bodies remain largely unaffected by their children's births, but that doesn't mean that they're untouched by parenting on a deeper level. How can childrearing affect dads' testosterone levels? And does it make them less manly? See more »

10 Things Women Should Know about Male Hormones

Ah, testosterone, the male hormone with the bad-boy reputation. But does it really cause aggression in men? Do women also secrete testosterone in their bodies? Find out what else women need to know about male hormones. See more »

10 Causes of Testicular Pain You Shouldn't Ignore

If you're like most men, you'd rather ignore the pain than go to the doctor and talk about pain "down there." But in many cases, trying to pretend the pain away could mean worsening your problem -- even to the point of needing your testicles removed. See more »

Testosterone and Estrogen Balance in Men

Testosterone and estrogen are actually very closely related in the body, and maintaining the balance of these hormones is key to preventing health issues. Learn about proper testosterone and estrogen balance in men. See more »


What is the definition of circumcision? Learn about the origins, risks and benefits of circumcision. See more »


What is the definition of ejaculation? Learn about what's happening during ejaculation and its purpose in reproduction. See more »


What is the definition of an erection? Learn what's happening during an erection and how dysfunction occurs. See more »