Shaft

The main part of the penis is called the shaft. When you get horny or ‘turned on’, the shaft can grow bigger and harder. This is called an erection. The penis contains a lot of blood vessels. During an erection, these fill with blood. A sticky fluid may then be released from the penis – this is known as ejaculating.

During puberty, people may get erections randomly, even when they’re not feeling horny. This is totally normal and nothing to worry about. These erections will go down by themselves.

The tip of the penis is called the head or the ‘glans’. This part of the penis is really sensitive. The layer of skin that protects this part of the penis is called the foreskin. To keep things clean, it’s a good idea to gently pull your foreskin back and clean underneath it with warm water every day. Some people may not be able to pull their foreskin back until they are a bit older, so it’s best to be really gentle with this area of your body. 

Many people enjoy having their shaft and glans touched (or stimulated) during sex and masturbation. Remember, everyone likes to be touched in different ways. 

Testicles

Below the penis are the testicles. Just like with penis size, testicles vary in size from person to person. It’s totally normal for one testicle to hang lower than the other.

Testicles are responsible for producing millions of sperm cells every day. Sperm travels out of the body through the penis, however there are some tubes that first get the sperm from the testicles to the penis. These tubes are called the epididymis, the vas deferens, and the urethra. As well as carrying sperm, the urethra also helps the body get rid of pee which is stored in the bladder.

The testicles produce hormones called androgens. One type of androgen is testosterone. Increases in testosterone during puberty cause changes to the body. These include deepening of the voice, hair growth on the face and chest, widening of shoulders, and muscle growth.

Prostate

The prostate is located below the bladder (where pee is stored) and next to the rectum (where poo is stored), and is about the size of a golf ball. The prostate and seminal vessels create fluid which combines with the sperm to make semen. This is what comes out of the penis when a person ejaculates. Many people enjoy having their prostate stimulated during sex and masturbation. Remember, everyone likes to be touched in different ways.