ejaculation: When a man emits sperm from his penis as a result of orgasm.

epididymis: A lumpy section that lies on top of the testicle.

epididymitis: An infection of the epididymis gland; easily diagnosed by a doctor and treated with antibiotics.

erect: Stiff and hard, generally referring to a penis during a state of arousal.

erectile dysfunction; ED: Physical or psychological condition when a man is unable to have an erection (varying degrees of severity).

erection: A penis that is in a state of arousal, becoming stiff and hard.

estrogen: A female hormone; plays a key role in triggering the process needed to create a baby; no longer produced after menopause.