vestibular system

The vestibular system, which contributes to balance in most mammals and to the sense of spatial orientation, is the sensory system that provides the leading contribution about movement and sense of balance.

This is the system of balance

Dizziness, fatigue, and nausea are the most common symptoms of motion sickness

. Motion sickness or kinetosis, also known as travel sickness, is a condition in which a disagreement exists between visually perceived movement and the vestibular system's sense of movement. Depending on the cause, it can also be referred to as seasickness, car sickness, simulation sickness or airsickness.

^Cause

The most common hypothesis for the cause of motion sickness is that it functions as a defense mechanism against neurotoxins.^[7] The area postrema in the brain is responsible for inducing vomiting when poisons are detected, and for resolving conflicts between vision and balance. When feeling motion but not seeing it (for example, in a ship with no windows), the inner ear transmits to the brain that it senses motion, but the eyes tell the brain that everything is still. As a result of the discordance, the brain will come to the conclusion that one of them is hallucinating and further conclude that the hallucination is due to poison ingestion. The brain responds by inducing vomiting, to clear the supposed toxin.

Motion sickness is a common problem in people traveling by car, train, airplanes and especially boats. Motion sickness can start suddenly, with a queasy feeling and cold sweats. It can then lead to dizziness and nausea and vomiting.
Your brain senses movement by getting signals from your inner ears, eyes, muscles and joints. When it gets signals that do not match, you can get motion sickness. For example, down below on a boat, your inner ear senses motion, but your eyes cannot tell you are moving.
Where you sit can make a difference. The front seat of a car, forward cars of a train, upper deck on a boat or wing seats in a plane may give you a smoother ride. Looking out into the distance - instead of trying to read or look at something in the vehicle - can also help.

Signs and Symptoms:

The most common signs and symptoms of motion sickness include:

• Nausea
• Pale skin
• Cold sweats
• Vomiting
• Dizziness
• Headache
• Increased salivation
• Fatigue

Preventive Care:

There are several ways you can try to prevent motion sickness:

• Sit in the front seat in a car.
• Keep your eyes on the horizon. Don't read.
• Rest your head against the seat back, to keep it still.
• Turn the air vents toward your face.
• Don't smoke.

Causes:

Motion sickness happens when the body, the inner ear, and the eyes send conflicting signals to the brain. This most often happens when you are in a car, boat, or airplane, but it may also happen on flight simulators or amusement park rides. From inside a ship's cabin, your inner ear may sense rolling motions that your eyes cannot see. On the other hand, your eyes may see movement on a "virtual reality" ride that your body does not feel. Once a person gets used to the movement and the motion stops, symptoms may come back (although usually only briefly). Sometimes just thinking about movement can cause anxiety and symptoms of motion sickness. For example, a person who had motion sickness before might become nauseous on an airplane before take-off.