Olfaction

Olfactory Epithelium

Small region of turbinates and septum high in the nasal cavity

Olfactory Receptor Neurons

Long receptor cells, have an axon extending directly into the olfactory bulb (CNS)

Olfactory Cilia

Specialized projections in olfactory sensory neurons (OSN) detecting odorants. Many per cell but only have one specific receptor.

Basal Cells

Stem cells for olfactory receptor cells

Odorant

Binds the olfactory receptor molecule on olfactory cilia, then activating a G-protein coupled cascade to generate an AP.

Olfactory Receptor

Many different olfactory receptor molecules, with each receptor cell making just one

Olfactory Neuron Axons

Specific receptor protein synapses on glomeruli at a patterned location in the olfactory bulb. Information input from olfactory neurons having specific olfactory receptor proteins is physically separated in the olfactory bulb.

Glomerulus

Receives input from a specific axon from a specific receptor then relays through mitral cells to olfactory cortex of brain.

Mitral cells

Relay information from glomerulus to olfactory cortex

Combinatorial Theory

Compare all olfactory receptors activated to understand the specific smell (not one to one)

Anosmia

Loss of smell

Dysosmia

Dysfunction of olfactory system