Cancer and its treatments can affect male sex organs.
The male sexual organs include the penis, testicles and prostate gland. The male sex hormones are also important for a man’s sexuality and sex life.
The male reproductive system includes the penis; the testes and epididymides, held within the scrotum; the vas deferens, and internally, the seminal vesicles, and the prostate gland.
The penis is the male sex organ. It is made up of the shaft and the head. The head of the penis is covered by a moveable piece of skin called the foreskin.
The urethra is a tube that runs from the bladder, through the middle of the penis, to carry urine out of the body.
The penis has a rich blood supply, as well as a muscle layer and nerves. When sexually aroused the blood flow increases and the penis becomes erect.
The testes produce sperm and the hormone testosterone. Next to each testis is the epididymis, a tube where sperm is stored. When the penis is erect sperm moves from the epididymis and through the vas deferens to the seminal vesicles.
The seminal vesicles make a fluid that mixes with sperm.
The prostate gland, is about the size of a walnut. It surrounds the first part of the urethra and adds more fluid to the sperm.
During orgasm, the prostate squeezes this fluid into the urethra and out of the body.
For information about cancers that can start in the male reproductive system, go to cruk.org/cancer-types.
The penis and testicles
The penis is partly inside and partly outside the body. It’s made up of several types of tissue. These include skin, muscle, blood vessels and nerves. Inside the penis lies the urethra. Urine and semen flow through this tube and eventually pass out of the small slit at the end of the penis (the meatus).
The end of the penis is also known as the head of the penis (glans). It's normally covered by a piece of skin called the foreskin (prepuce). But some men may have had the foreskin removed during an operation called a circumcision. This operation is usually done at birth but may be done later in life.
For most men the ridge below the head of the penis (the frenulum) is the most sensitive part of their penis. The scrotum is the pouch of skin that hangs below the penis and holds both testicles (testes). The testicles are part of the male reproductive system.
From the age of puberty the testicles produce sperm, which can fertilise a female egg. The testicles produce the male sex hormone, testosterone.
The prostate gland
The prostate is a small gland about the size of a walnut. It surrounds the top part of the tube that carries urine from the bladder to the penis (the urethra). The same tube also carries semen. The prostate produces a thick clear fluid, which is an important part of the semen.
The growth and function of the prostate gland depends on the male sex hormone testosterone, which is produced in the testes.
A man's back passage (anal area), chest and nipples may be very sensitive during sexual activity. Like women, men are all different and there may be other parts of their body that are more sensitive.
Male sex hormones
Testosterone is the main male sex hormone. It is made in the testicles. Testosterone is the main cause of male qualities such as:
- a deep voice
- body hair growth
- muscle development
- the ability to have an erection
- sex drive (libido)