KINESIOL 1Y03 Lecture Notes - Olfactory Bulb, Olfactory Epithelium, Lingual Papilla
6 Feb 2013
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Document Summary
Sense of smell occurs in response to odours that stimulate receptors located in the extreme superior region of the nasal cavity. Only a small superior part of the nasal cavity is dedicated to olfaction. Olfactory epithelium is the nasal epithelium in the olfactory region. 10 million olfactory neurons are present within the olfactory epithelium. Axons of these bipolar neurons project to the olfactory bulbs where they synapse with secondary neurons. Olfactory tracts project from the bulbs to the cerebral cortex. Dendrites of olfactory neurons extend to the epithelial surface of the nasal cavity, and their ends are modified into bulbous enlargements called olfactory vesicles. These vesicles possess cilia called olfactory hairs . Airborne molecules enter the nasal cavity and are dissolved in the fluid covering the olfactory epithelium. Some of these odorants bind to transmembrane odorant receptor molecules of the olfactory hair membranes. A g protein, associate with each odorant receptor, is activated by the binding of the odorant.
