physiology of olfaction Flashcards
what is olfaction ?
the ability to smell
what diseases are associated with a reduced sense of smell ?
parkinson’s
epileptic seizures
alzheimer’s disease
what is the first order neuron of thee olfactory pathway ?
olfactory sensory neurones
where are the receptors of the olfactory sensory neuron located ?
upper nasal concha surrounded by a layer of mucus
what gland secretes thee mucus surrounding the receptors of the olfactory pathway ?
bowman’s gland
what is the olfactory nerve formed from ?
axons of thee sensory olfactory neuron
where does the olfactory nerve pass through ?
cribriform plate of ethmoid
what type of receptors are in the olfactory pathway ?
g coupled receeptors
how are the olfactory receptors stimulated ?
gaseous odorant particles bind to the g coupled receptors on the dendrites of the olfactory sensory neurons
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this binding stimulates either cAMP or IP3
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this causes an influx of calcium and sodium and an efflux of chlorine
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this causes depolarisation of the neuron
where does olfactory discrimination begin ?
in the olfactory neuron
what is the second order neeuron of the olfactory pathway ?
mitral and tuft cells
this synapse happens at the glomeruli at the surface of the olfactory bulb
what forms the olfactory tract ?
axons of the mitral and tuft cells ( el second order neurons )
what is the pathway after reaching the olfactory tract ?
olfactory trigon : dividing into 3 striae
the lateral pathway
medial pathway
and the intermediate pathway
what is the function of the lateral pathway ?
reaches areas of the primary olfactory cortex of the temporal lobe to perceive stimuli
what is the function of the medial olfactory pathway ?
goes to the limbic structures
