chapter 15- ears and taste Flashcards
sense of smell
olfaction
what stimulates sensory receptors in olfactory region at superior portion of nasal cavity
odor
what is lines with olfactory epithelium
cell bodies and dendrites of 10 million olfactory neurons
olfactory receptor cells=
chemoreceptors
dendrites of olfactory neurons extend to what surface
epithelial surface
dendrites of olfactory neurons extend to epithelial surface of what
nasal cavity and ends are modified into bulbous enlargements
dendrites of olfactory neurons extend to epithelial surface of nasal cavity and ends are modified into bulbous enlargements=
olfactory vesicles
olfactory vesicles have
cilia
receptor molecules react to about how many odors
4000
receptor molecules are classified into 7 primary classfications which are
- camphor
- musk
- floral
- peppermint
- ethereal
- pungent
- putrid
when receptor saturated with odorant (no longer responds)=
adaptation (less sensitive)
primary olfactory neurons undergo what kind of replacement
constant replacement
how are primary olfactory neurons unique
ability as most neurons permanent
the entire olfactory epithelium degenerates about when
every 2 months
primary olfactory neurons are replaced by
basal cells
olfactory neuron axons go through foramina in the ….
cribiform plate
cribiform plate->
olfactory bulb
secondary neurons relay information to the …
brain
how do secondary neurons relay information to the brain
olfactory tracts
central olfactory cortex involved in
stimuli perception
neural pathways are able to perceive what?
specific odors
neural pathways are able to perceive specific odors, as well as ?
emotional and autonomic responses
does some information passes through the thalamus vs 2nd pathway?
yes
secondary olfactory areas=
hypothalamus, hippocampus, structures of limbic system
inability to smell
anosmia
is anosmia congenital
yes
if anosmia is acquired it is usually due to
head injury causing olfactory nerve tear
what is related to nasal cavity inflammation or neurological disorder (parkinsons)
anosmia
anosmia may be early sign of
alzheimers
smells associated with danger trigger what
sympathetic fight or flight response
smells associated with food=
appetite stimulant-> salivation vs repulsion as protective reflex
what is detected by taste buds
gustatory stimuli
bumps on tongue, named for shape
papillae
most numerous on tongue surface, no taste buds
rough surface= manipulate food easily
filiform
largest and fewest papillae, form v shaped row between anterior and posterior tongue
vallate (wall surrounds)
in folds along sides of tongue
most abundant in kids, amount decreases with age
adults= posterior
foliate
scattered throughout superior tongue, small red dots
fungiform
ovoid structures embedded in tongue and mouth epithelium
taste buds
what detects taste stimuli
taste buds
what is mostly along edges of tongue papillae, and also seen in other tongue areas, the palate, lips and throat
taste buds
each taste bud is about how many taste cells or gustatory cells
50
each taste cell has what
microvilli
each taste cell has microvolli that go through what?
taste pore
taste buds are also
basal and supporting cells
taste buds that are also basal and supporting cells are
nonsensory