The term main olfactory system (OSYm) refers to one of two types of olfactory system (OLS). The other is the accessory olfactory system (OSYa). The OSYm consists of main olfactory receptor neurons (ORNm), olfactory nerve (1n), main olfactory bulb (MOB), olfactory tract (oltr) and via the oltr to the anterior olfactory nucleus (AON) ( Buck-2013 ), nucleus of the olfactory tract (NOL), olfactory tubercle (OTB), tenia tecta (TTT), ( Amaral-1992 Swanson-2004 ), piriform cortex (PIR), amygdala (AMG) and entorhinal cortex (ENT) ( Buck-2013 ). For more on functions of the OSYm), see olfactory system (OSY). Final 16 Jan 2025.