What Does the Immune System Do? If you've ever wondered how your immune system works, this movie is for you!

If your child has a serious illness like cancer or a chronic (ongoing) condition like asthma, your doctor might talk to you about enrolling your child in a clinical trial. A clinical trial is a study ...

What Is the Respiratory System? When we breathe, the respiratory system takes in oxygen and sends out carbon dioxide. The cells in our bodies need fresh oxygen to stay alive. As cells do their jobs, ...

What Is a Tear-Duct Blockage? A tear duct is a small tube that drains tears from the eyes. Tears are made in glands under the eyelids. They wash over the eyes to keep them moist and clean. Then, they ...

What Is Developmental Dysplasia of the Hip? Developmental dysplasia of the hip (DDH) is a problem with the way a baby's hip joint forms. Sometimes the condition starts before the baby is born, and ...

Testicular torsion is an emergency condition. It happens when the spermatic cord, which provides blood flow to the testicle, rotates and becomes twisted. The twisting cuts off the testicle's blood ...

Are you thinking about volunteering? Planning for life after high school? This section offers help with homework, dealing with bullying, finding a summer job, and lots more.

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 ...

What Is the Digestive System? The digestive system breaks down the food we eat into tiny parts to give us fuel and the nutrients we need to live. As food breaks down, we get amino acids from protein, ...

What Does the Heart & Circulatory System Do? If you've ever wondered how your heart works, this movie has the answer. And special thanks to the Fred J. Brotherton Charitable Foundation for supporting ...

Your body has a "highway" system that sends blood to and from your body parts. It's called the circulatory system and the roads are called arteries and veins. Arteries, which usually look red, carry ...

What Is the Digestive System? Food is our fuel, and its nutrients give our bodies' cells the energy and substances they need to work. But before food can do that, it must be digested into small pieces ...