How Does Air Enter the Respiratory System? Air enters the respiratory system through the nose or the mouth. If it goes in the nostrils (also called nares), the air is warmed and humidified. Tiny hairs ...

Girls have lots of questions about the body changes of puberty. When will my breasts grow? What's the "normal" age to get your first period? Watch this video and find out!

An erection is when the penis gets hard because sponge-like tissue in it fills with blood. Erections tend to make the penis get bigger and stand away from the body. Erections can go away on their own ...

The chances of getting pregnant while using fingers during sex (“fingering”) are very low. Fingering itself can’t cause pregnancy. But it’s possible for a pregnancy to happen if sperm gets on a finger ...

We see and hear about hearts everywhere. A long time ago, people even thought that their emotions came from their hearts, maybe because the heart beats faster when a person is scared or excited. Now ...

All kids get a fever from time to time. Usually, a fever isn’t dangerous or bad for kids. It can even be a good thing because it can help the immune system fight infection. Still, parents might be ...

It may be tempting to take the summer off and relax, but looking for a job will give you helpful life skills. Finding a job may be hard, but the search will be worth it. Jobs are out there. Even if ...

Earaches are common in kids and can have many causes. Here’s why they happen and what to do when your child complains of ear pain. Give acetaminophen or ibuprofen as needed to ease pain (check the ...

Both the brain and the spinal cord are protected by bone: the brain by the bones of the skull, and the spinal cord by vertebrae, a set of ring-shaped bones. They're both cushioned by layers of ...

Most blood tests take only a few minutes. They’re done at some doctor’s offices, and at community labs, diagnostic centers, and hospitals. A doctor, nurse, or phlebotomist (fleh-BOT-eh-mist, someone ...

It’s normal for people to masturbate (touch or rub their own genitals because they like the way it feels). Some people do it to relieve stress or tension. It’s nothing to be ashamed of or embarrassed ...

As a parent, you want your kids to feel happy about themselves and have good self-esteem (also called a self-image). Your words and actions affect it more than anything else, starting from when ...