Gustation Flashcards
gustation
a chemical sense involved with taste
flavor
the perception of taste
- =taste + olfaction
- influenced by smell, intensity, mouth feel….
retronasal olfactory sentation
the sensation of an odor that is perceived when chewing and swallowing force an odorant in the mouth up behind the palate into the nose
- smells coming from mouth while eating
what happens if we lose our taste but not our smell
we still wont be able to taste
chorda tympani
the branch of cranial nerv 9 that carries taste info from the anterior, mobile tongue
trigeminal sense
the sense that signals the presence of irritant in the mouth and contribute to the mouth feel of food
- like spicy or menthol
properties of taste
- onset/aftertaste
- intensity
- qualities (sweet, salty…)
- hedonics
- localization
tastetants
molecules that taste receptors recognize and respond to by producing neural signals that the brain represents as perceptions of different tastes
- they get dissolved in saliva
salt
- contain cation and anion
- it changes over time and the intensity can change
sweet
- glucos, sucrose of fructose
- one type of receptor for sweet food
- artificial sweeteners also bind there
sour
- comes from acidic substances
- can be dangerous at high concentrations
biter
- usually unpleasant
- can signal toxic food
- quinine is a prototypical biter substance
umani
- savory flavor that typically indicates proteins
- msgs
papillae
tiny structures on surfaces of th mouth mainly on the tongue that contain taste buds
filiform
papillae that have no taste buds
circumvallate
circular shaped structures that form a v shape on the back of the tongue
- we only have 8-12 of these but they have 200-700 tastebuds
foliate
- folds of tissue containing taste buds on the rear of th tongue
- small ridges on the back and side
- few hundred buds in the folds
fungiform
- mushroom shaped papillae distributed densely on the sides and tip of tongue
- about 6 in each
taste bud
structures that contain receptors within the papillae
- each bud contain 40-100 taste receptor cells
taste receptor cell
elongated neurons packed within the taste buds that transduce tastants into neural signals
- contain cilia
- die after a week
cilia
slender projections on the tips of some taste buds that extend into the taste pore
- contain the binding sites
receptor cells
a type of trc that contains receptors that initate transduction of sweet, umami, and bitter
- g coupled
- one type of receptor on cilia
presynaptic cells
type of TRC that are in the form of ion channels that transduce salty and sour
- each neuron has a channel for both
- synapse with cranial nerve fibers
inhibition
process where descending signals block pain reception in the mouth so we can still eat even when hurt
two models of signal passage
- labeled line model
- across fiber pattern model
labeled line model
each cranial nerve fiber carries information about a single taste quality from a single type of receptor
across fiber pattern model
cranial nerve fibres carry information about combinations of taste qualities from multiple types of receptors
- population coding
cranial nerve in taste
7 9 and 10
gustation pathway
cranial nerves - nucleus of the solitary tract in the brainstem - ventral posterior medial nucleus of the thalamus - and then to the cortex - then to the amygdala, hippocampus or oFC
primary taste cortex
- split between the anterior insular cortex and the frontal operculum
- it represents taste quality
amygdala
representation of emotion
hypothalamus
representation of hunger
orbitofrontal cortex (ofc)
representation of reward value of food
specific hunger theory
the idea that a deficiency of a particular nutrient produces a craving for it
- only for sweet and salty
taste adaptation
constant application of certain foods temporarily weakens subsequent perception
cross adaptation
taste of one food can affect the taste of another
- sour gets worse after eating sweet
supertaster
having the gene and a high density of fungiform papillae makes you habe the most intenst taste sensations
orthonasal olfaction
smelling through the nostrils
- good smells dont always make you want to eat it
- can affect aversion
capsaicin
- the chemical that produces the burn in chilis
- binds to heat receptors
- variability on people who like/dont like spicy foods
