Did you sleep your way through that middle school health class? Test your knowledge here!

Melatonin is a hormone that is produced by the pineal gland and helps to regulate the body's sleep-wake cycle.

The patella is a small, flat, triangular bone that sits in front of the knee joint. It helps to protect the knee joint and improve the leverage of the quadriceps muscles when the knee is extended.

Ataxia is a neurological condition that affects a person's ability to coordinate muscle movements, leading to a loss of control and coordination. This can result in difficulties with balance, walking, and fine motor skills. Ataxia can be caused by a variety of factors, including genetic mutations, infections, and other underlying conditions.

The aorta is the largest artery in the human body. It originates from the left ventricle of the heart and carries oxygen-rich blood to the rest of the body.

Measles, also known as rubeola, is a highly contagious viral disease that is spread through the air when an infected person coughs or sneezes. The virus causes a characteristic rash on the skin, which often starts on the face and spreads to the rest of the body. Measles can cause serious complications, particularly in young children, including pneumonia, encephalitis (inflammation of the brain), and even death.