If you've ever been sick to your stomach while riding in a car,
train, airplane, or boat, you know exactly what motion sickness
feels like. It's no fun. To understand motion sickness, it helps
to understand a few parts of your body and how they affect the
way you feel movement: Inner ears: Liquid in the semicircular
canals of the inner ear allows you to sense if you're moving,
and, if you are, which way you're moving — up, down, side to
side, round and round, forward, or backward. Eyes: What you see
also lets your body know whether you're moving and in which
direction. Skin receptors: These receptors tell your brain which
parts of your body are touching the ground. Muscles and joint
sensory receptors: These sensing receptors tell your brain if
you're moving your muscles and which position your body is in.
The brain gets an instant report from these different parts of
your body and tries to put together a total picture about what
you are doing just at that moment. But if any of the pieces of
this picture don't