CH 15-18 Packets (BIO 181) Flashcards
(159 cards)
what are the two properties of sound and how are they measured?
loudness: amplitude dB
pitch: frequency Hz
where does the external ear end?
tympanic membrane
where do we see the first and second level of amplfication of sound
1st: ossicles
2nd: oval window
where does transduction of sound energy occur?
cochlea
what are the three fluid filled compartments of the cochlea
scala vestibuli
scala media
scala tympani
in which compartments are perilymph and endolymph found?
perilymph: scala vestibuli; scala tympani
endolymph: scala media
what are the receptor cells
hair cells
what types of ion channels are located at the tips of the stereocillia of hair cells
mechanically gated
what happens when the steriocillia bend towards the tall stereocillia
channels open (depolarization) potassium enters cell
what happens when the steriocillia bend towards the short steriocillia
channels close (hyperpolarization) potassium doesnt enter cell
describes the neural pathway for sound
hair cells synapse on afferent axons of CN VIII, cochlear enters brainstem, synapse with 2nd order neuron to 3rd order neuron and travels to auditory cortex to cranial nerve 8
what are the two branches of the vestibylocochlear nerve and what is their function
- vestiular—-> equilibrium
2. cochlear—> hearing
what are the three types of cells in the olfactory epithelium and what is their function
- supporting cell—> secrete mucous
- receptor cells—>neurons that respond to odorants
- basal cells—> regeneration
what important proteins are found in mucus and what is their function
olfactory binding protiens
Describe the steps involved in olfactory signal transduction
chemicals dissolve in mucus, travel to receptor cells, trigger production of cAMP—> depolarization of receptor cells, then receptors send axons through cribiform plate to brain
what happens to the axons of the receptor cells of olfaction once they have depolarized
receptors send their axons through cribriform plate towards brain
map out the neural pathway for olfaction
olfactory nerve—> olfactory bulb—>olfactory tract to olfactory cortex (NO THALAMUS)
what are the three types of lingual papillae
curcumvallate, fungiform, filiform
how many taste buds would be found in the circumvallate papillae
100
how many tast buds would be found in the fungiform papillae
5
what is the only function of th filiform papillae
only to provide friction (NO TASTE BUDS)
what two types of cells are found in the taste buds
basal and gustatory
describe the four primary tastes and what rimary transduction mechanism is used by each
- sour: H+ binding with K+ (depolarize)
- salty: Na+(depolarize)
- bitter: nitrogen (ligands) (depolarize)
- sweet: ligands (depolarize)
describe the neural pathway for taste
receptor cells to afferent neurons via CN VII, IX, X –> CNs synapse to 2nd order neurons that project to thalamus, 3rd order neurons terminate in gustatory cortex in parietal lobe.