Topic 12- The Chemical Senses Flashcards
What is gustation/taste?
What is olfaction?
What is flavour?
3pts
Taste: When molecules (often associated with food) enter the mouth and stimulate receptors on the tongue
Olfaction: When airbourne molecules enter the nose and stimulate receptors in the nasal cavity
Flavour: What we experience from combining the two
What are some unique properties that distinguishes chemical senses from all other systems?
3pts
- Directly in contact with the external environment
- Constantly exposed to the outside world
- Regenerate: 5-7 weeks for olfaction and 1-2 weeks for gustation/taste
Affective component:
Bad for us =
Good for us =
Bad for us= taste/smell unpleasant
Good got us= taste/smell pleasant
Taste/gustation and smell senses are also called “BLANK” senses
Why?
3pts
Gate keeper senses:
–> Identify things we need for survival and what can be safely consumed
–> Detect things that are bad for the body and that should be rejected
Our perceptions resulting from this tongue receptor stimulation are described in terms of five taste qualities, what are they?
5pts
- Salty
- Sweet
- Sour
- Bitter
- Umami (savory, meaty)
Sweetness is often associated with compounds that…
What is it needed for? What is it a source of?
4pts
have nutritive or caloric value, typically carbohydrates
- Typically in the form of sugars = the “ose’s “
- Needed for survival (glucose and the brain)
- Energy source
What is sourness? What does it do to the body?
4pts
- Sourness causes an automatic bodily response that prepares the GI system to get ready to process food
- “Acidity”
- Salivation increases
- Stomach acid gets produced (heartburn)
What is bitterness? What does it do to the body? What is the detection threshold like?
4pts
- Bitterness has the opposite effect of sourness- it tends to trigger automatic rejection responses that help an organism avoid harmful substances
- Survival
- Poisons (arsenic and cyanide)
- Of the 5 has the lowest detection threshold (barely needs to be in your mouth the detect it)
What is saltiness? What does it do to our body when we lack it?
2pts
- Saltiness indicates the presence of sodium
- When deprived or we lose a lot sweating, we seek out food that taste salty to replenish
What is savory? What does it do to our bodies?
3pts
- Savoury foods usually indicate protein content
- Indicates the presence of glutamate (excitatory neurotransmitter)
- Long lasting source of energy for our body
Physiology for taste- What is on the tongue that allows us to taste?
What contains the taste buds?
5pts
4 categories of the papillae of the tongue:
- Filiform: Found all over the surface of the tongue; only ones present in the center/high concentration in in the center; gives it the rough appearance
- Fungiform: Found at the side and tips of the tongue
- Foliate: Series of folds found along the sides and back of the tongue
- Circumvallate: Mounds at the back of the tongue
–> All except for Filiform contain taste buds
Approximately how many taste buds does the tongue contain?
How many taste cells does each taste bud contain? What do taste cells do?
- About 10,000 taste buds on the tongue
- Each taste bud contains 50 to 100 taste cells
—> Where transduction for gustation occurs
–> Converts chemicals from the environment into electrical activity
Generally, what is the taste process?
Combined, what does this make up?
In general, once chemicals from the environment reach the taste cells, electrical activity is produced. That is transmitted from the tongue, through the cranial nerves, then to the thalamus, then to the insula/frontal operculum.
–> These two combined make up the primary gustatory cortex (GC)
Which of the 5 taste qualities do mammals prefer most?
- Preference for sweet things
Which animal doesn’t show a preference for sweet things and considered to be “sweet blind”?
Cats
