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:
- 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.
- The eyes observe where the body is in space (i.e., upside down, right side up, etc.) and also the directions of motion.
- Skin pressure receptors such as those located in the feet and seat sense what part of the body is down and touching the ground.
- Muscle and joint sensory receptors report what parts of the body are moving.
- 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.