Exam #6: Taste & Olfaction Flashcards
List the five primary sensations of taste.
Sour Salty Sweet Bitter Umami
What substances elicit sour taste?
Acids e.g. HCl
What substances elicit salty taste?
Ionized salts i.e. NaCl
What substances elicit sweet taste?
Sugars
Glycols (poisoning)
Alcohols
Amino acids
What substances elicit bitter taste?
Alkaloids
Caffeine
Nicotine
What substances elicit umami taste?
MSG
Glutamate
Amino acids
*Meat & cheese
What cranial nerves are involved in transmitting taste information?
CN VII
CN IX
CN X
Which cranial nerve innervates the anterior 2/3 of the tongue?
CN VII
Which CN innervates the back of the tongue?
CN IX
Which CN innervates the soft palate, the epiglottis and esophagus?
Soft palate= CN VII
Epiglottis & esophagus= CN X
How do we classify taste receptor cells? Is it a neuron?
Taste buds are specialized sensory receptor for taste transduction
How do we classify olfactory receptor cells? is it a neuron?
Olfactory receptors are bipolar neurons
What is the average life span of taste receptor cells? How does this compare to olfactory neurons?
Taste= 10 days- 2 weeks Olfactory= ~60 days
What is the biological role of taste?
- Protection–bitter substances can stimulate protrusion of the tongue and gag
- Edibility
- Diet selection
- Taste aversion
What is the biological role of olfaction?
- Combine with taste to get gustatory sensation
- Pharamones for sex
What is bait-shyness?
If an animal feels sick after eating, assumption is that the novel food is responsible–animal will lose taste for the food
What is the clinical significance of bait-shyness?
This is how we lose a taste for something that has been perceived to make us sick
What is hyposmia?
Decrease sense of smell
What is anosmia?
No sense of smell
What is parosmia?
Perversion of the sense of smell
What is hypogeusia?
Less taste sensation
What is ageusia?
No taste sensation
What is parageusia?
Perversion of the sense of taste i.e. a bad taste in the mouth
Outline the afferent pathway of taste information.
1) CN
2) NTS
3) VPM of the Thalamus
4) Insular & frontal taste cortices
