There are a number of distinct external parts, as shown in this diagram:
The foreskin is a flap of skin that covers the tip of the penis (the glans) and it can slide back and forwards to hide or expose it. Sometimes this flap of skin is cut away and this process is called circumcision, resulting in a circumcised penis.
As with most parts of our bodies, foreskins come in many different shapes and sizes, and may completely cover the glans or not:
Internally, there are a number of important organs. The testes or testicles produce sperm, which is used to fertilise the egg produced by a the female body. The sperm pass along a duct and a liquid called semen is produced by glands attached to these tubes. The semen is used to carry the sperm out through the urethra.
The urethra also carries urine from the bladder out through the penis when urinating.
When ready for sex, the penis fills with blood, swells and stands up – this is called an erection. When this happens, the foreskin slides back revealing the glans.
* Here we talk about the “male” body in a biological sense, but please note that gender depends on more than just your body – see our section on gender identity.