gustation and olfaction dsa Flashcards
what keeps the nasal cavity moist?
ducts and glands in epithelium
where are the dendrites and receptors of olfactory cells?
in olfactory epithelium
lamina propria holds what?
immune cells
important because immune cells exposed to environment
what is held in basal cells?
under basement membrane
stem cells for olfactory neurons, constantly turnover 30-60 days
what does olfactory tract do?
connects olfactory bulb to brain
what is the cribiform plate?
part of ethmoid bone that olfactory receptor neurons pass through to synapse in olfactory bulb
name layers in olfactory bulb superficial to deep
olfactory neurons
glomerulus
external plexiform layer
mitral cell layer
granular cell layer
to
lateral olfactory tract
what do granular cells do
regulate other cells in olfactory bulb
what do mitral cells do
main carriers of sensory info
receive afferents from receptor neurons, send them to brain
what does the external plexiform layer do
contains dendrite of tufted, mitral, granule cells, cross talk between these cells
granule cells release GABA to modulate mitral/tufted cell activity here
what does the glomerular layer do?
this is where afferent sensory info comes from environment to olfactory bulb
what is the olfactory nerve layer?
contain receptor of olfactory receptor neurons
what do centrifugal fibers do?
help regulate feedback loops
what are the components of the olfactory tract?
lateral olfactory tract
cells of anterior olfactory nucleus
fibers of anterior commisure
what effect does centrifugal fibers have on granule cells, what does it cause?
positive effect
causes them to decrease mitral and tufted cell activity
what do periglomerular cells do
antagonize activity of mitral and tufted cells, get used to smells, make them go away
shut transmission of info from these cells to brain
how many types of gpcr does one glomerulus receive?
one, but from many neurons
how does info get from olfactory bulb to olfactory cortex
lateral olfactory tract
carried by mitral and tufted cells
where can info from olfactor bulb go?
any part of olfactory cortex
where are taste buds?
throughout oropharyngeal cavity
taste buds on soft palate are innervated by what?
greater superficial petrosal nerve
sensory fiber cell bodies of facial nerve VII located in?
geniculate ganglion
sensory fibers of facial nerve synapse where?
solitary tract
describe steps of central taste pathway
synapse in solitary nucleus
travel thru ipsilateral central tegmental tract
go to VPM, synapse
to
frontal operculum and anterior insular cortex via
posterior limb of internal capsule
to
brodmann area 3b
what is hyposomia, what causes it?
decreased sensitivity to odorants
nasal polyps
what is ageusia?
loss of taste totally, rare
what is hypogeusisa
reduced taste sensitivity
dysguesia?
commonly due to drug use, taste perception altered
damage to distal geniculate ganglion?
taste may or may not be lost
ipsilateral facial paralysis for sure
