Heart

Your heart is a muscular organ that acts like a pump to send blood throughout your body all the time.

Your heart is at the center of your circulatory system, which delivers blood to all areas of your body. An electrical system regulates the heart and uses electrical signals to contract the heart walls. When the walls contract, blood is pumped into your circulatory system.

Your blood carries the oxygen and nutrients that your organs need to function normally. Blood also carries carbon dioxide, a waste product, to your lungs to be passed out of your body and into the air. A healthy heart supplies the areas of your body with the right amount of blood at the right rate needed to function normally. If disease or injury weakens your heart, your body organs wont receive enough blood to function normally.

Noise

Noise is all around you, from televisions and radios to lawn mowers and washing machines. Harmful sounds - sounds that are too loud or loud sounds over a long time - can damage sensitive structures of the inner ear and cause noise-induced hearing loss.

More than 30 million people in the U.S. are exposed to hazardous sound levels on a regular basis. Hazardous sound levels are louder than 80 decibels, which isn't as loud as traffic on a busy street. Listening to loud music, especially on headphones, is a common cause of noise-induced hearing loss. Keeping the volume down when listening to music and wearing earplugs when using loud equipment can help protect your hearing.

There are two main types of hearing loss. One happens when your inner ear or auditory nerve is damaged. This type is permanent. The other kind happens when sound waves cannot reach your inner ear. Earwax build-up, fluid or a punctured eardrum can cause it. Untreated, hearing problems can get worse. If you have trouble hearing, you can get help. Possible treatments include hearing aids, special training, certain medicines and surgery.

Genetic Brain Disorders

A genetic disorder is a disease caused by a different form of a gene, called a variation, or a change in a gene, called a mutation. Genetic brain disorders specifically affect the development and function of the brain.

Some genetic brain disorders are due to random gene mutations or mutations caused by environmental exposure, such as cigarette smoke. Other disorders are inherited, which means that a mutated gene or group of genes is passed down through a family. Still other disorders are due to a combination of genetic changes and other outside factors. Some examples of genetic brain disorders include leukodystrophies, phenylketonuria, Tay-Sachs disease, and Wilson disease.

Many people with genetic brain disorders fail to produce enough of certain proteins that influence brain development and function. These brain disorders can cause serious problems that affect the nervous system. Some are life-threatening.

Vitamins

Vitamins are substances that your body needs to grow and develop normally. There are 13 vitamins your body needs. They are vitamins A, C, D, E, K and the B vitamins (thiamine, riboflavin, niacin, pantothenic acid, biotin, vitamin B-6, vitamin B-12 and folate). You can usually get all your vitamins from the foods you eat. Your body can also make vitamins D and K. People who eat a vegetarian diet may need to take a vitamin B12 supplement.

Each vitamin has specific jobs. If you have low levels of certain vitamins, you may develop a deficiency disease. For example, if you don't get enough vitamin D, you could develop rickets. Some vitamins may help prevent medical problems. Vitamin A prevents night blindness.

The best way to get enough vitamins is to eat a balanced diet with a variety of foods. In some cases, you may need to take a daily multivitamin for optimal health. However, high doses of some vitamins can make you sick.