Final answer:
Motion sickness is caused by conflicting information from the visual and vestibular systems. Anti-emetics antagonize the H1 receptor at the vestibule area and brainstem to alleviate motion sickness symptoms.
Step-by-step explanation:
Motion sickness is caused by conflicting information from the visual and vestibular systems. When motion is perceived by the visual system without vestibular stimuli, or through vestibular stimuli without visual confirmation, the brain triggers emesis and associated symptoms. The area postrema, located next to the fourth ventricle in the brain, is responsible for vomiting and can respond to toxins in the bloodstream, as well as motion.
Anti-emetics, which are drugs used to combat motion sickness, work by antagonizing the H1 receptor at the vestibule area and brainstem. This antagonistic action helps to alleviate the symptoms of motion sickness. By blocking the H1 receptor, these anti-emetics reduce the stimulation that leads to emesis and provide relief for individuals experiencing motion sickness.