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.

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 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?

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 ...

What Are the Lungs and Respiratory System? The lungs and respiratory system allow us to breathe. They bring oxygen into our bodies (called inspiration, or inhalation) and send carbon dioxide out ...

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 Mitral Valve Prolapse? Mitral valve prolapse is a common heart condition. It happens when there’s a problem with how one of the heart's valves works. Heart valves keep blood moving through the ...

The Internet is amazing! But it also has some things you need to watch out for. You're always you, of course. But if you use a smartphone, tablet, or computer to play games and text with friends, you ...

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 ...

Gynecology ("gyn" for short) is a medical field that focuses on the female reproductive system. A gyn checkup is a yearly health check — like a regular eye exam or dental checkup. Doctors often call ...

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 ...

What Is Coarctation of the Aorta? Coarctation of the aorta (COA) is a narrowing of the aorta, the major blood vessel that carries blood away from the heart to the body. This narrowing causes the left ...