The olfactory bulb sits on top of the cribiform plate and receives input from the olfactory receptor neurons in the nose. It is the first stage of olfactory processing, and the outputs of the bulb project directly to cortex – without going through a thalamic intermediate.
Because the olfactory system is a phylogenetically ancient system, it is closely associated with allocortical structures as well as the limbic system.
Although it is called the Olfactory Nerve (CN I), the olfactory tract is already a post-synaptic CNS structure.
