ABSTRACT
In most mammals, chemicals, particularly volatile ones, are sensed by several intranasal systems, the main olfactory organ (tuned to odors in general), the vomeronasal or Jacobson’s organ (tuned to chemicals employed in social and sexual activities) (Evans, 2002) (see Chapter 46), the septal olfactory organ (a patch of olfactory tissue on the anterior septum of some vertebrates that likely responds to the same agents as the main olfactory system, and perhaps serves an alerting role) (Adams, 1992), and the trigeminal intranasal somatosensory system (responsive to pungent and irritative odors) (see Chapter 47). Humans likely do not possess a septal organ, and their vomeronasal organ is rudimentary and nonfunctional (Giorgi et al., 2000; Smith et al., 2001; Trotier et al., 2000).
