sensation and perception exam 1 Flashcards
what is the resting potential of a neuron in millivolts?
-70 mv
what 3 cranial nerves innervate tongue?
7 (facial nerve), 9 (glossopharyngeal nerve), 10 (vagus nerve)
What is the across fiber pattern of taste?
each taste fiber responds best to one stimulus, but also responds to a lesser extent other stimuli
what is the labeled line model of taste?
if the labeled line model was correct each taste bud would be devoted to one aspect of taste quality ( example: only sweet)
how is mild sourness detected on presynaptic cells?
sour channels open, allowing for hydrogen ions from acids to flow in
how is aversive saltiness detected on presynaptic cells?
Aversive saltiness channels open, allowing for the sodium ions to flow in
how is mild saltiness detected on presynaptic cells?
ENaC channels open, allowing sodium ions to flow in
what receptor type pairings on receptor taste cells are used to detect bitter?
T2R1, T2R2, T2R3 ( any T2 type of receptor)
what are the 4 steps of a signal being sent from a gustatory receptor to the amygdala, hypothalamus or the orbitofrontal cortex?
- the signal leaves the tongue via the cranial nerves
- the signal then is passed on to the nucleus of the solitary tract
- the signal then enters the primary taste cortex ( anterior insular cortex and the frontal operculum
4.the signal then passes onto either the amygdala, hypothalamus or the orbitofrontal cortex
why does food taste weird on planes? how is taste affected?
- facial cranial nerve 7 passes by the eardrum and can be stimulated by sound .it is thought that the simulation of the auditory branch of this nerve interferes with taste.
- saltiness, bitterness, and sourness are all unaffected by plane noise. sweetness is diminished and umami is enhanced by the noise.
how do odor stimuli from food in the mouth reach the olfactory mucosa?
the odorants reach the olfactory mucosa via the retronasal route
why do people feel calmer when vibrations are sent through headphones?
the vibrations stimulate the vagus nerve which is part of the parasympathetic nervous system which is associated with “rest and digest”
what happens to your ability to taste when you hold your nose closed? what taste quality is unaffected by this?
orange colored cherry soda tastes less like cherry than red colored cherry soda
where are the response from taste, vision, touch and smell first combined in the brain? what kind of neurons that are specific to this region and why are they special? how is the firing of these neurons affected by hunger?
- orbitofrontal cortex,
- bimodal neurons: they respond to two senses ( taste and smell or taste and vision)
- firing rate of bimodal neurons increases with hunger and decreases with satiation
what gene is associated with normal bitterness tasters?
AVI
what 3 factors are responsible for individual differences in taste?
- genetics
- experience
- cultural practices
at what stage in utero can a fetus detect tastants?
14 weeks
at what stage in utero can a fetus’s olfactory receptor neurons detect odorants?
24 weeks
what is the absolute threshold?
the minimum stimulation needed to detect a particular stimulus 50% of the time
what is the difference threshold?
the minimum difference between two stimuli required for detection 50% of the time
what is psychophysical scaling?
the process of measuring how changes in stimulus intensity relate to changes in the perceived intensity
