TRIP

Motion sickness

Better Health Channel (Australia), 2004

Motion sickness is the unpleasant sensation of nausea and dizziness that some people experience when riding in a moving vehicle.
Motion sickness can be brought on by travelling in cars, boats, submarines, aeroplanes, trains, by riding amusement rides that spin, and even when using a swing at a playground.
Astronauts in zero-gravity space can also suffer from a form of motion sickness, called 'space adaptation syndrome'.
Frequent vomiting can lead to dehydration and low blood pressure, so it is important to seek prompt medical attention if you are severely affected.
Other popular terms depend on the mode of transport: for example, airsickness, carsickness or seasickness.
Symptoms of motion sickness can include: Generally feeling unwell Excessive production of saliva Headache Nausea Dizziness Hyperventilating Heavy sweating Weakness Losing colour in the face or turning red Vomiting.
Inside the inner ear is a series of canals filled with fluid, called the labyrinth, which includes the semicircular canals.
When the head is moved, the rolling of the fluid inside these canals tells the brain exactly how far, how fast and in what direction the head is moving.
Information from these canals is passed along to the brain via the vestibular nerve, which lies next to the cochlear nerve.
The brain also relies on information from the eyes and from the muscles themselves (called 'muscle sense' or kinaesthesia).
The brain uses the inner ear, the eyes and muscles to pinpoint the position of the body at all times.