Balance: A biological system that enables us to know where our bodies are in the environment and to maintain a desired position. Normal balance depends on information from the inner ear, other senses (such as sight and touch) and muscle movement.

Our sense of balance is specifically regulated by a complex interaction between the following parts of the nervous system:

1. The inner ears (also called the labyrinth) monitor the directions of motion, such as turning or forward-backward, side-to-side, and up-and-down motions.
2. The eyes observe where the body is in space (i.e., upside down, right side up, etc.) and also the directions of motion.
3. Skin pressure receptors such as those located in the feet and seat sense what part of the body is down and touching the ground.
4. Muscle and joint sensory receptors report what parts of the body are moving.
5. The central nervous system (the brain and spinal cord) processes all the bits of information from the four other systems to make some coordinated sense out of it all.