How does our sense of balance work?
Motion sickness relates to our sense of balance and equilibrium. Researchers in space and aeronautical medicine call this sense spatial orientation, because it tells the brain where the body is "in space:" what direction it is pointing, what direction it is moving, and if it is turning or standing still.
Our sense of balance is regulated by a complex interaction of 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.