Nausea, the unpleasant feeling of needing to vomit, represents awareness of afferent stimuli to the medullary vomiting centre. Vomiting is the forceful expulsion of gastric contents caused by involuntary contraction of the abdominal musculature when the gastric fundus and lower esophageal sphincter are relaxed. Vomiting should be distinguished from regurgitation, the spitting up of gastric … Continue reading Nausea and Vomiting