JohnQ
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Carsickness is just one form of motion sickness. Usually, people with carsickness will experience the same symptoms no matter how they are travelling, whether it is by plane, train, automobile, or boat. Many astronauts also suffer from a similar ailment that is referred to as space sickness. Some people, however, do not experience every type of motion sickness. It can occur or be more pronounced in vehicles where the movement is more sudden or noticeable such as in a boat or plane. In fact, the word nausea comes to us from the Greek word naus, meaning ship. Studies show that two-thirds of all people suffer from some form of motion sickness in severe travelling conditions. In mild, or smooth, conditions, the number drops to one-third.
Motion is detected in our body through three different neural pathways to the brain. These pathways are the inner ear, the eyes, and sensors deep in the body called proprioceptors. The inner ear controls balance and orientation. The eyes detect movement visually. The proprioceptors detect the body’s parts in relation to itself. When we move ourselves, all three of the pathways coordinate in bringing the sense of motion to our brain. Sometimes, when the movement comes from a source outside our own body, the three pathways are unable to coordinate the sense of motion and our brain gets confused. The more complex the movement, such as when there is sudden acceleration and deceleration, or the movement is bumpy, the more confused the brain becomes.
Scientists are still unsure of the exact mechanism that internally causes motion sickness, but they know that it has to do with levels of the neurotransmitters norepinephrine, acetylcholine, and histamine. Over-the-counter medicines used to help treat or prevent motion sickness work by controlling the levels of these neurotransmitters.
 Posted 5514 day ago
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