Guide to the Penis

Everything you need to know about that mysterious member

Anatomy

OK, so you've got the basics down: penis and balls. But there's obviously more to a man than that. Without getting all medical on you, here's a breakdown of the male anatomy:

The Glans:
The penis is responsible not only for sex and reproduction but also for necessities like releasing urine. The end, or head of the penis, also called the glans, contains the opening of the urethra where both semen and urine are expelled. Where the glans meets the shaft is the most sensitive part of the penis.

Foreskin:
Guys whose parents didn't subject them to penis-o-plasty as infants will have an extra layer of skin called foreskin, which covers the whole penis including the glans. Foreskin is a loose tube only attached at the base and head and can slide over the rest of the penis easily. When a non-circumcised man is excited and the penis is erect, the foreskin can be pulled back to reveal the head of the penis.

Erectile Tissue:
The penis is made up of erectile tissue that expands and grows when blood flows into it then traps the blood to keep the penis erect. After ejaculation--or after a while without sexual stimulation--the blood is released and the penis becomes flaccid again. Testicles: The testes (balls or gonads) are housed behind the penis in the scrotum, a not-so-lovely looking loose sack of skin. Testes produce sperm and sex hormones like testosterone.

Vas deferens:
The vas deferens is a sperm duct that starts in the scrotum and carries semen past the bladder into the urethra.

The prostate:
This gland, which sits under the bladder, adds a milky fluid to the semen. The fluid protects sperm from the acidity of the vagina. The prostate is also known as the male G-spot and can be stimulated through the anus.

Secrets and myths

Blue Balls:
Hopefully you're not still dealing with adolescent-like sore scrotum complaints when you don't put out, but if you want to know the truth, "blue balls" is actually a legitimate ailment. When the blood trapped in the penis and balls isn't released, it's uncomfortable. Sex isn't the only way to relieve the pain: aspirin, a shower, or a little time will also solve the problem.

Matters of size:
The human penis is the largest of any living primate, meaning your man's member is probably bigger than that of an ape! When flaccid, the average length is between three and four inches and when erect, it's between five and six inches. The average penis circumference when erect is between 3.5 and 3.9 inches.

Boners, literally:
Humans are one of the few species that don't have a strengthening bone in their penises. Whales, bears, rodents, and cattle are just some of the animals that do.

Lower life forms:
When erect, the penis takes on the characteristics of an earthworm, using a form of support called a "hydrostatic skeleton."

Kegels for guys:
Just like women, men can strengthen their PC muscles by squeezing and releasing the muscle. This can help guys control ejaculation and enhance their orgasms.

Penis colour:
Penises are generally darker than the rest of the body due to the maturation process and because those members are manhandled so much. It's true. Speaking of masturbation: It's healthy and can help keep his organs healthy into old age.

Image credit: Zurijeta/Thinkstock images