sensation and perception exam 1

Question 1

what is the resting potential of a neuron in millivolts?

Answer 1

-70 mv

Question 2

what 3 cranial nerves innervate tongue?

Answer 2

7 (facial nerve), 9 (glossopharyngeal nerve), 10 (vagus nerve)

Question 2

What is the across fiber pattern of taste?

Answer 2

each taste fiber responds best to one stimulus, but also responds to a lesser extent other stimuli

Question 3

what is the labeled line model of taste?

Answer 3

if the labeled line model was correct each taste bud would be devoted to one aspect of taste quality ( example: only sweet)

Question 4

how is mild sourness detected on presynaptic cells?

Answer 4

sour channels open, allowing for hydrogen ions from acids to flow in

Question 5

how is aversive saltiness detected on presynaptic cells?

Answer 5

Aversive saltiness channels open, allowing for the sodium ions to flow in

Question 6

how is mild saltiness detected on presynaptic cells?

Answer 6

ENaC channels open, allowing sodium ions to flow in

Question 7

what receptor type pairings on receptor taste cells are used to detect bitter?

Answer 7

T2R1, T2R2, T2R3 ( any T2 type of receptor)

Question 165

what are the 4 steps of a signal being sent from a gustatory receptor to the amygdala, hypothalamus or the orbitofrontal cortex?

Answer 165

1. the signal leaves the tongue via the cranial nerves 2. the signal then is passed on to the nucleus of the solitary tract 3. 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

Question 166

why does food taste weird on planes? how is taste affected?

Answer 166

- 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.

Question 167

how do odor stimuli from food in the mouth reach the olfactory mucosa?

Answer 167

the odorants reach the olfactory mucosa via the retronasal route

Question 168

why do people feel calmer when vibrations are sent through headphones?

Answer 168

the vibrations stimulate the vagus nerve which is part of the parasympathetic nervous system which is associated with "rest and digest"

Question 169

what happens to your ability to taste when you hold your nose closed? what taste quality is unaffected by this?

Answer 169

orange colored cherry soda tastes less like cherry than red colored cherry soda

Question 170

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?

Answer 170

- 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

Question 171

what gene is associated with normal bitterness tasters?

Answer 171

AVI

Question 172

what 3 factors are responsible for individual differences in taste?

Answer 172

- genetics - experience - cultural practices

Question 173

at what stage in utero can a fetus detect tastants?

Answer 173

14 weeks

Question 174

at what stage in utero can a fetus's olfactory receptor neurons detect odorants?

Answer 174

24 weeks

Question 175

what is the absolute threshold?

Answer 175

the minimum stimulation needed to detect a particular stimulus 50% of the time

Question 176

what is the difference threshold?

Answer 176

the minimum difference between two stimuli required for detection 50% of the time

Question 177

what is psychophysical scaling?

Answer 177

the process of measuring how changes in stimulus intensity relate to changes in the perceived intensity