Special Senses - Napa Valley College...1 Special Senses Olfaction, Gustation, Hearing, Equilibrium Olfaction via CNI • Link between smell, memory, and emotion • Olfactory sensory
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Olfactory PathwaysThe olfactory epithelium lies high within the nasal cavity, and its olfactory neuronsproject to the olfactory bulb. Sensory inputat the receptors is carried through theolfactory cortex to the cerebral cortex and the limbic system.
Olfactory neurons in the olfactory epithelium live only abouttwo months. They are replaced by new neurons whose axonsmust find their way to the olfactory bulb.
Sound wave sstrike the tympan icmembrane and be come vib rations.
The sound wave e ne rgy istransfe rre d to the th re e bone so f the midd le e ar,wh ich vib rate .
The stape s isattache d to the membrane o f the ovalwindow.Vib rationso fthe ovalwindowcre ate flu id wave swith in the coch le a.
The flu id wave spush onthe fle xib le membrane so f the coch le arduct.Hairce llsbe nd and ion channe lsope n ,cre atingan e le ctrical signal thatalte rsne u ro transmitte r re le ase .
Sound wave sstrike the tympan icmembrane and be come vib rations.
The sound wave e ne rgy istransfe rre d to the th re e bone so f the midd le e ar,wh ich vib rate .
The stape s isattache d to the membrane o f the ovalwindow.Vib rationso fthe ovalwindowcre ate flu id wave swith in the coch le a.
The flu id wave spush onthe fle xib le membrane so f the coch le arduct.Hairce llsbe nd and ion channe lsope n ,cre atingan e le ctrical signal thatalte rsne u ro transmitte r re le ase .
Ne uro transmitte rre le ase on to se nso ryne u ronscre ate saction po te n tials that trave lth rough the coch le arne rve to the b rain .
Sound wave sstrike the tympan icmembrane and be come vib rations.
The sound wave e ne rgy istransfe rre d to the th re e bone so f the midd le e ar,wh ich vib rate .
The stape s isattache d to the membrane o f the ovalwindow.Vib rationso fthe ovalwindowcre ate flu id wave swith in the coch le a.
The flu id wave spush onthe fle xib le membrane so f the coch le arduct.Hairce llsbe nd and ion channe lsope n ,cre atingan e le ctrical signal thatalte rsne u ro transmitte r re le ase .
Ne uro transmitte rre le ase on to se nso ryne u ronscre ate saction po te n tials that trave lth rough the coch le arne rve to the b rain .
Ene rgy fromthe wave stransfe rsacross the coch le arduct in to thetympan icductand isd issipate d back in to the midd le e arat theround window.
A t rest: About 10% of t he i on channel s are open, and a t oni c si gnal i s sent by t he sensory neuron.
Exci tati on: When t he hai r cel l s bend i n one di rect i on, t he cel l depol ar i zes, w hi ch i ncreases act i on pot ent i al f requency i n t he associ at ed sensory neuron.
Inhi bi ti on: I f t he hai r cel l s bend i n t he opposi t e di rect i on, i on channel s cl ose, t he cel l hyperpol ar i zes, and sensoryneuron si gnal i ng decreases.
Ti p l i nk
St ereoci l i um
Hai r cel l
Some channel sopen.
Pri marysensoryneuron
M ore channel sopen.Cat i on ent rydepol ar i zescel l .
Channel s cl osed. Less cat i on ent ry hyperpol ar i zes cel l .
Act i on pot ent i al s Act i on pot ent i al s i ncrease. No act i on pot ent i al s
mV
A cti on potenti al s i n pri mary sensory neuron Ti me