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 ...

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 ...

How much do you know about your digestive system? Find out by taking this quiz!

Did you know you have more than 600 muscles in your body? They do everything from pumping blood throughout your body to helping you lift your heavy backpack. You control some of your muscles, while ...

Sexually transmitted diseases (STDs) are infections spread from person to person during sex (vaginal, oral, or anal) or close sexual contact. STDs are also called sexually transmitted infections, or ...

If your parents decide to divorce, you may have a lot of emotions and questions. That’s OK because it’s a big change for the whole family, including you. There’s plenty you can do to start to feel ...

This is a general outline of the milestones on the road to reading success. Keep in mind that kids develop at different paces and spend varying amounts of time at each stage. If you have concerns, ...

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 ...

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 ...

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 ...

Right ventricle (VEN-trih-kul): one of the four chambers of the heart. The right ventricle pumps blood low in oxygen to the lungs. In the lungs, the blood then gets a "refill" of oxygen.

A night terror (also called sleep terror) is similar to a nightmare, but is far more dramatic. A child having a night terror wakes up screaming and is impossible to ...