Motion sickness is caused The "CTZ," or chemoreceptor trigger zone, is a specific region located within the medulla oblongata of the brain, essentially acting as a sensory area that detects chemicals in the blood and triggers the vomiting reflex when stimulated, making it a key part of the vomiting center situated in the medulla oblongata itself; in simpler terms, the CTZ is a specialized area within the medulla that monitors blood chemistry and initiates nausea and vomiting if it detects harmfu