Special Senses III Flashcards
What are the signals for spicy food?
Nociceptors
What is the chemical for spice? What is its MOA?
Capsaicin–Opens VR1 receptor
What are the 5 taste sensations?
Sour Salty Sweet Bitter Umami
True or false: At moderate concentrations of taste stimuli, sour, salty, sweet and bitter tastes can be perceived by stimulating any area containing taste receptor cells
True
Where are the taste buds on the tongue?
In the trenches along papilla
The tip of the tongue is most sensitive to what tastes? (3)
Sweet
Umami
Salt
The sides and back of the tongue are more sensitive which two tastes?
Sour and bitter
What happens if you cut the nerve to a taste bud?
Oh yeah, it dies
True or false: the basal cells can turn into taste buds
True
True or false: we all have about the same number of taste buds
False
True or false: taste has a strong genetic component
True
What is the innervation to the anterior 2/3 of the tongue?
C VII
What is the innervation to the posterior 1/3 of the tongue?
CN IX
What is the innervation of the soft palate?
CN VII
What is the innervation of the epiglottis and esophagus?
CN X
Where do all of the taste tract combine? What part of the thalamus does this area then project to?
Nucleus of the solitary tract, then to the ventral posterior medial nucleus of the thalamus
What part of the cortex senses tastes?
Insular taste cortex
What is the role of the amygdala in taste?
Motivation of food
How are salt and sour sensed?
Opens an ion channel
How are sweet, bitter, and umami sensed?
G-protein coupled receptor
Depolarization of taste cells cause what?
release of neurotransmitters onto primary afferent nerves.
True or false: there is a labeled line to the taste cortex
True
What is the bait-shyness (Sauce Bearnaise) phenomenon?
Losing taste for a food that the brain associated with sickness
What is hypogeusia?
Decreased taste sensation
What is ageusia?
Absence of taste
What is parageusia?
Perversion of the sense to taste; a bad taste in the mouth
What is unique about CN I? (3)
Exposed
Bypasses thalamus
Regenerate
What type of neurons are the olfactory nevelets?
Bipolar neurons
How do we smell stuff (how do the nervelets sense odors)?
Binding of odoriferous molecule to receptor on cilia of olfactory receptor cell.
What are the cells that produce mucus for the olfactory bipolar cells?
Bowman’s glands
What do odiferous molecules bind to?
G-protein coupled receptors
How many different functional odorant receptors in humans?
around 400
Olfactory neurons expressing the same type of olfactory receptor project where?
The same glomeruli
True or false: there is one receptor for every odor
False–An odorant might interact with several different types of olfactory receptors
What is the function of the neurons that project from the olfactory bulb to the gustatory cortical areas?
Olfactory and gustatory signals may be integrated here to generate the perception of flavor.
What is the route of the olfactory projections that go to the medial dorsal nucleus of the thalamus?
projects to the orbitofrontal cortex
What is the function of the orbitofrontal cortex?
This cortical area is thought to be involved in the perception and discrimination of odors
What is the role of the limbic system in the olfactory system?
probably mediate affective component of odors - whether odor pleasant or unpleasant
What is specific anosmia?
lowered sensitivity to a specific odorant even though sensitivity to other odorants seems normal
What is general anosmia?
Complete loss of sense of smell
Is hyposmia transient or chronic?
Either
What happens to odor sensitivity in Alzheimer’s disease?
greatly diminished or distorted sense of smell
