Olfactory Nerve - Cranial Nerves Olfactory Nerve(CNI...

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Cranial Nerves Olfactory Nerve (CNI) Olfactory Nerve (CNI) Olfactory Nerve (CN I) * The receptors cells for smell form a patch of epithelium of about 5cm 2 (olfactory mucosa) in the roof of the nasal cavity. * It covers part of the superior nasal concha and septum. * Olfactory receptor cells are neurons with a modified dendrite consisting of a swollen tip bearing 10-20 cilia called olfactory hairs . * The hairs are immobile and have binding sites for odor molecules * The basal end of the cell tapers to become an axon. * These axons collect into small fascicles that leave the nasal cavity through pores ( cribriform foramina ) in the ethmoid bone * Collectively, the fascicles are regarded as cranial nerve I (olfactory nerve) * The olfactory cells ( OC ) are a form of bipolar neuron that serve as transducers of chemical sensations into neural signals. * They are the only neurons in the body directly exposed to the external environment. * Molecules with a "scent" bind to the surface of these cells and in so doing the modify the cell membrane's charge characteristics, sending a signal via a long axon back to the brain. * The axons of these neurons are bundled together to form the
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This note was uploaded on 01/30/2012 for the course BSC BSC1085 taught by Professor Sharonsimpson during the Fall '10 term at Broward College.

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Olfactory Nerve - Cranial Nerves Olfactory Nerve(CNI...

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