CNS gustatory and olfactory Flashcards
Describe the major structures on the tongue that allow you to taste.
The tongue has papillae with about 10 000 Taste buds. Then the taste goes through the taste pore and reach the taste cells.
How does information about flavour end up at the brain?
The tongue -> papillae -> Taste buds -> taste cells -> taste pore -> taste afferent
What are the 5 basic tastes?
Salty, Sour, Bitter, sweet and Umami
When you taste salty food, what is going on chemically in the tongue?
The dissolved sodium in the food flows through ion channels and depolarizes afferents
When you taste sour food, what is going on chemically in the tongue?
The extra low pH in saliva interacts with ions channels
Why do we experience bitter taste?
to understand different taste that could be dangerous
When you taste bitter food, what is happening chemically in the tongue?
- Channels are blocked
- Trigger G-Protein cascades that then interact with channels
When you taste sweet food, what is happening chemically in the tongue?
G-protein cascades are activated and interact with ion channels
When you taste umami, what is happening chemically in the tongue?
The glutamate receptors of the tongue start G-protein cascades
If you add sodium glutamate to food, what taste are you enhancing ?
Salty and Umami
Describe the pathway that taste signals follow after leaving the tongue.
The cranial nerves carry out to the thalamus and then reach the ipsilateral gustatory cortex
Describe how a smell reaches the brain.
Nasal cavity -> Olfactory epithelium -> Cilia -> Olfactory receptor cells -> Olfactory nerve -> Olfactory bulb -> Brain
Describe the 3 steps involved in olfactory signal transduction.
1) the odorant that was dissolved in the mucus binds to receptors
2) A G-Protein cascade is activated
3) Ion channels open
How many oderant receptor types do we have?
1000 types
Why do we discriminate many different odours?
A same odorant can bind to more than one type of receptor and so create a population code
