User:NicoBarfo

14th century illustration of vomiting from the Casanatense Tacuinum Sanitatis

Receptors on the floor of the fourth ventricle of the brain represent a chemoreceptor trigger zone, known as the area postrema, stimulation of which can lead to vomiting. The area postrema is a circumventricular organ and as such lies outside the blood-brain barrier; it can therefore be stimulated by blood-borne drugs that can stimulate vomiting or inhibit it.