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 Is Fetal Alcohol Syndrome (FAS)? Babies whose mothers drank alcohol during their pregnancy can be born with birth defects and developmental disabilities. The problems that can happen when babies ...

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!

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

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 an Atrial Septal Defect? An atrial septal defect (ASD) — sometimes called a hole in the heart — is a type of congenital heart defect in which there is an abnormal opening in the dividing wall ...

Reproduction is the process by which organisms make more organisms like themselves. But even though the reproductive system is essential to keeping a species alive, unlike other body systems, it's not ...

The roller coaster hesitates for a split second at the peak of its steep track after a long, slow climb. You know what's about to happen — and there's no way to avoid it now. It's time to hang onto ...

Stretch marks are fine lines in the skin that happen when quick growth or weight gain stretches the skin (like during puberty). Skin is usually fairly stretchy, but when it's overstretched, the normal ...

What Are Strains and Sprains? A strain is when a muscle or tendon (tissue that attaches muscle to bone) is stretched too far. A strain is sometimes called a "pulled muscle." Depending on the level of ...

It's easier to agree than disagree. But we can learn a lot from conversations where we don't see eye to eye — if we can listen and talk rationally, that is. Unfortunately, many us either shy away ...

Coughing is a healthy reflex that helps clear the airways. A severe cough or one that lasts more than a week requires a medical checkup. But many coughs are caused by a virus that just needs to run ...