The penis
The penis is an external male sex organ. It’s part of the male reproductive system
and urinary system (also collectively known as the
The penis hangs in front of the pouch of skin (scrotum) that contains the testicles.
Structure
The penis is made of different types of tissue, including skin, nerves, smooth muscle and blood vessels.
The penis has 3 parts.
The glans is the head of the penis. It’s covered by a loose fold of moveable skin called the foreskin (prepuce). The foreskin may be removed by a surgery called circumcision.
The shaft is the main part of the penis. It’s between the glans and the lower tummy.
The root is the base of the penis within the pelvis.
Within the penis there are 3 chambers of spongy tissue containing many blood vessels.
The corpora cavernosa (singular: corpus cavernosum) are the 2 upper chambers of the shaft that make up most of the penis.
The corpus spongiosum is the lower chamber of the shaft that surrounds the urethra.
The
Function
The penis plays a role in both sex and urination.
When sexual arousal develops, the nerves signal to the blood vessels inside each corpus cavernosum to fill these chambers with blood. As blood flow increases, the spongy tissue of the penis expands and causes the penis to become stiff (erect) and enlarged. Once a penis is erect, it can be inserted during penetrative sex.
If ejaculation occurs,
During urination, the urethra carries urine (pee) from the bladder to the outside of the body.
Find out more about male sex organs and reproductive system.
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