1. Where in the brain is the vomiting center located? A. Hypothalamus B. Medulla oblongata C. Pons D. Midbrain: Answer B The vomiting center of the brain lies in the medulla oblongata. 2. Antiemetic agents, such as domperidone and haloperidol, are antagonistsfor which receptors? A. 5-Hydroxytryptamine (5-HT) serotonin B. Histamine-2 C. Acetylcholine D. Dopamine: Answer D Metoclopramide, domperidone, and haloperidol are dopamine antagonists, makingthem effective antiemetic agents. 3. What type of vomiting is caused by the direct stimulation of the vomitingcenter by neurologic lesions involving the brainstem? A. Retch B. Periodic C. Duodenal D. Projectile: Answer D Of the available options, only projectile vomiting is caused by the direct stimulationof the vomiting center by neurologic lesions, such as increased intracranial pressure,tumors, or aneurysms involving the brainstem.