The temporomandibular joint (TMJ) connects the lower jaw to the skull. You can feel your two TM joints and their movement by placing your fingers directly in front of your ears and opening your mouth.

From enjoying the great outdoors to playing sports safely, here's how to protect yourself and deal with emergencies.

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, ...

You can't control what other drivers do. But you can do things to lower your chances of being in a crash. This is what it means to be a defensive driver. Before you get behind the wheel, get into the ...

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, ...

Every single person has a skeleton made up of many bones. These bones give your body structure, let you move in many ways, protect your internal organs, and more. It's time to look at all your bones — ...

Parents do everything they can to protect their children. But sadly, many kids have gone through trauma. A trauma is any event that is deeply upsetting, scary, or harmful. Things like abuse, violence, ...

How Does the Brain Work? And How Does the Nervous System Work? How do you remember the way to your friend's house? Why do your eyes blink without you ever thinking about it? Where do dreams come from?

What Does the Heart Do? The heart is a pump, usually beating about 60 to 100 times per minute. With each heartbeat, the heart sends blood throughout our bodies, carrying oxygen to every cell. After ...

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 ...

Having a shy style isn't necessarily a problem. It's perfectly OK to take time to warm up to new people and situations. But shyness blocks some people from being as comfortable or sociable as they'd ...

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 ...