One area of our bodies that we tend to focus much of our attention on is our genitals. The penis is an important part of your body that will change during puberty. Penises vary in size and appearance, but when an adult penis is erect they are mostly a similar size. So there is no need to worry if you think your penis looks a little smaller than or different to other people’s.
Diagram 1 and 2: Male reproductive system (front on and side view)
The penis
How do I look after my foreskin?
Sometimes the foreskin – a fold of skin which covers the tip of the penis (glans) – is removed surgically at birth. This operation is known as circumcision. Doctors rarely recommend circumcision, but for some boys it is performed due to cultural and religious beliefs. In previous generations, circumcision was common, but now only about 10% of boys born in Australia are circumcised each year. Sometimes boys are circumcised for medical reasons, but this is not common. Regardless, the penis works the same way with or without a foreskin.
For those with a foreskin, it is very important to keep the area beneath the foreskin clean. The foreskin should be pushed back daily and the glans gently washed.
Why does my penis go hard?
One physical sign of sexual feelings for boys is when they get an erection.
When the penis is stimulated, or a boy becomes sexually aroused, it grows from being small, limp and soft to larger, erect and hard. The penis does not contain any bones and is not made of muscle. It becomes erect because the tissue inside it fills with blood under pressure.
Penises vary in size and appearance. There is a large natural variation, but when they are erect, they are mostly a similar size.
A thick whitish fluid is produced by the seminal vesicle and the prostate gland. This mixes with the sperm to form semen. At the peak of sexual excitement – when a male ’reaches climax’, ‘comes’ or has an orgasm – semen is pumped out of the end of the erect penis. This is called ejaculation. The milky fluid or ejaculate (‘come’, ‘cum’) contains 200 to 500 million sperm. During sexual excitement, but before orgasm or ejaculation, a small amount of clear fluid may be released from the penis. The clear fluid is called ‘pre-cum’ and can also carry live, active sperm
What happens to my urine when I ejaculate?
Semen passes from the testicles through the spermatic cord before being ejaculated through the urethra – the same tube that urine passes through. It is impossible for urine and semen to become mixed because the flow of urine is automatically stopped when your penis is erect.
What is a wet dream?
During puberty, you can become sexually excited or aroused quite easily. Ejaculations can happen while you are asleep. These are called nocturnal emissions, or ‘wet dreams’. Wet dreams are completely normal. They are your body’s way of getting rid of a build-up of semen in your body.
When you wake up after a wet dream, your sheets or pyjamas may feel slightly sticky. Sometimes you may remember the good feeling you had in the night, or you may remember nothing at all.
The testes
During puberty, there is a change in your testicles (testes).
With help from the male hormone testosterone, the testicles begin to produce sperm. Sperm are tadpole-shaped and their ‘tails’ help them move. This movement of sperm is important for reproduction. Sperm are so tiny that they can only be seen under a microscope.
The testicles need to be kept cool for the sperm to develop normally. This is why they hang outside the body in a sac (bag) called the scrotum. It is quite normal for one testicle (testis) to be larger or to hang lower than the other. At birth, some boys may have experienced what is called ‘undescended testicles’ where one or both testicles fail to move down into the scrotum. This is usually corrected after birth.
However, even testicles that have moved down into the scrotum will sometimes pull back up into the body, for instance in cold water, or during sex. This is quite normal. They will eventually move back into place on their own. Any concerns you have about differences in the testicles can be talked over with a doctor.
Why should I check my testicles?
Once you reach puberty, it is a good idea to regularly check the size and shape of your testicles. A good time to do this is in the shower.
The purpose of this check is to get to know the size, shape and texture of your testicles. It is perfectly normal for one of your testicles to be bigger than the other. But if you notice any changes in your testicles, especially an unusual lump, you must see a doctor. One of the most common cancers for men between the ages of 15 and 30 is cancer of the testes.