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 ...

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 ...

Our bodies create a lot of heat. Normally, they're cooled through sweating and by heat radiating through the skin. But in very hot weather, high humidity, and other conditions, this natural cooling ...

What Is a Perforated Eardrum? A perforated eardrum is a tear or hole in the ear's tympanic membrane (the eardrum). A perforated (PER-fer-ate-id) eardrum can hurt, but most heal in a few days to weeks.

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 ...

If you decide to have sex, it’s important to know about birth control, or contraception, so you can protect against unplanned pregnancy and sexually transmitted diseases (STDs). STDs are infections ...

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 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 ...

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

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 ...