Section 3 Taste and Olfaction Flashcards
What taste modalities warn against potential noxious chemicals?
Sour and bitter
Which 3 tastes rely on G-protein-coupled receptors?
Sweet, umami and bitter
Which taste modaity is T1R2 + T1R3?
Sweet
Which taste modality is T1R1 + T1R3
Umami
What protein is the same bw the sweet and umami receptors?
T1R3
Which taste modality is the T2R family?
Bitter
How are different better substances detected?
By diff members of the TR2 family of receptor.
Which tastes are type II cells assoc w?
sweet/bitter/umami
What NT is released by the sweet, bitter, umami modalities?
ATP
Through what cells does sodium enter the cells of the tongue?
Amiloride-sensitive channels (depolarizes cell and leads to NT release)
How do H ions enter or the sour modality?
Via PKD2L1 ion channels
What ions shut down K channels?
H+ ions
How can taste be modified?
Leptin: released by fat cells in response to eating to give a sense of satiation, to damp response to sweet tastants OR
Increase levels of endocannabinoids: increase responses to sweet tastants
Supertasters:
heightened taste, esp. bitter, more fungiform papilla
Are there more men or women super tasters?
women, 35% of women vs 15% of men
What do super tasters tend not to like?
green veggies like cabbage and kale
How long do taste chemoreceptor cells live?
10 days
What do new taste cells differentiate from?
Basal cells near the base of taste bud
how does chemo affect taste?
kills all the taste cells and they won’t be replaced until after chemo is stopped
Ageusia:
loss of some or all tastants
Hypogeusia:
dec sensitivity to some or all tastants
Dysgeusia:
distortion of taste of some or all or the perception of taste when stimulant is not there (gustatory hallucination)
Gustatory agnosia:
complete