恶心和呕吐可能是由于内脏机能失调、化学刺激、放射及前庭输入功能(运动失调)等原因引起。对恶心和呕吐的生理学、药理学已经作了广泛的研究。参与内脏和中枢神经系统之间复杂的相互作用以及与呕吐有关的几个脑区已被确定。这些脑区的简单图解见图1。化学感受器触发区(CTZ)位于第Ⅳ脑室的底部,延髓的背面,这是大脑没有血脑屏障防卫的部分。因此CTZ是露置于循环血液和脑脊液中。CTZ具有感觉性感受器功能,并能将呕吐冲 Nausea and vomiting may be due to visceral dysfunction, chemical irritation, radiation and vestibular input (motor disorders) and other causes. Physiology and pharmacology of nausea and vomiting have been extensively studied. Several complex brain regions involved in visceral and central nervous system involvement and vomiting have been identified. A simple illustration of these brain regions is shown in Figure 1. The Chemoreceptor Trigger Zone (CTZ) is located at the base of the IV ventricle, on the back of the medulla oblongata, which is part of the brain’s defense against the blood-brain barrier. Therefore, CTZ is exposed to circulating blood and cerebrospinal fluid. CTZ has a sensory receptor function, and can vomit red