Olfactory nerve or cranial nerve I

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Description:

The olfactory nerve is entirely sensory and contains axons that conduct nerve impulses for olfaction, the sense of smell. The olfactory nerve begins with bipolar receptor neuroepithlial cells in the olfactory epithelium, which covers the inferior surface of the cribriform plate and extends down along the superior nasal concha. Bundles of axons from these nerve cells pass through about 20 olfactory foramina in the cribriform plate of the ethmoid bone on each side of the nose. These 40 or so bundles of axons collectively form the right and left olfactory nerves.
The olfactory nerve axons end in paired extensions of the brain called the olfactory bulbs, which rest on the cranial surface of the cribriform plate. Within the olfactory bulbs, the axon terminals of olfactory receptors form synapses with dendrites and cell bodies of the next neurons in the olfactory pathway. The axons of these neurons make up the olfactory tracts, which extend posteriorly from the olfactory bulbs. Axons in the olfactory tracts end in the primary olfactory area in the temporal lobe of the cerebral cortex.