As a person inhales, air and scent molecules move past the smell receptors in the nose. In turn, the smell receptors relay a signal to the brain. Smells can trigger memories and emotional responses.
Update Date 11/10/2012
Updated by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, David R. Eltz, Stephanie Slon, and Nissi Wang.