Quick Facts
The axon is the process of a neuron by which impulses travel away from the cell body; at the terminal arborization of the axon, the impulses are transmitted to other nerve cells or to effector organs. The larger axons are surrounded by a myelin sheath (Dorland, 2011).
Related parts of the anatomy
Structure and/or Key Features
The axon is a principal component of the olfactory sensory neuron that conveys olfactory sensory information to the brain. The 0.2 μm diameter unmyelinated axons of the olfactory sensory neurons extend superiorly and traverse the basement membrane on their way to the lamina propria. Many of the unmyelinated axons coalesce into about 20 olfactory nerve fibers, which make up the olfactory nerves (CN I). These olfactory nerves travel to the olfactory bulb (where they synapse with mitral cells in the glomerular layer) via the cribriform foramina of the ethmoid bone, ensheathed by dura and arachnoid mater (Pearce et al, 2003). Olfactory information is conveyed to the cerebral cortex via the olfactory tract (Standring, 2016).
Anatomical Relations
Olfactory sensory neurons are bipolar neurons that are situated within the olfactory epithelium. Each neuron has two ends. One end has a 2 μm diameter solitary unbranched dendrite, which extends inferiorly towards the epithelial surface. The other end has a 0.2 μm diameter unmyelinated axon, which extends superiorly, and traverses the basement membrane on its way to the lamina propria (Standring, 2016). Their cell body lies interposed between the axon and the dendrite in the middle segment of the olfactory epithelium.
Function
The axon is a component of the olfactory sensory neuron. It conveys olfactory sensory information to the olfactory bulb during the process of olfactory transduction.
Clinical Correlates
—Anosmia
References
Dorland, W. (2011) Dorland's Illustrated Medical Dictionary. 32nd edn. Philadelphia, USA: Elsevier Saunders.
Standring, S. (2016) Gray's Anatomy: The Anatomical Basis of Clinical Practice. Gray's Anatomy Series 41st edition: Elsevier Limited.
