Gustatory system Flashcards
What is the stimulus for umami tastes?
- Savoury taste of glutamate
- Associated with MSG
How do we perceive flavours?
Different receptors for: - Taste - Texture - Smell Combined in the cortex
- Mixture of receptors for different tastes can be activated
Why are bitter tastes instintively rejected?
Often poisons
Which tastes have metabotropic receptors?
Bitter, sweet and umami
What is the processs of transduction for sour tastes?
- H+ into cell (as stimulus)
- Slightly depolarises, opening voltage gated Na+ channels
- Increases membrane potential
- Voltage gated Ca2+ channels open
- Release of neurotransmitter (5-HT)
What are the 4 types of lingual papillae?
1) Circumvallate
2) FIliform
3) Fungiform
4) Foliate
Describe foliate papillae
- Least abundant
- Only present for the first 2-3 years of life
Which tastes have ionotropic receptors?
Sour and salty
What is the stimulus for sour tastes?
H+
What do basal cells do?
Produce new taste cells every 10 days
What is the structure of the lingual papillae?
- Taste buds line the pores next to papilla
- ~100 taste cells (receptors) in taste buds
- Taste cells have microvilli which project into the taste pore and detect stimulus
- Have synapse at the base
Describe circuvallate papillae
- At the back of the tongue
- Bitter stimuli
Describe filliform papillae
- No taste buds
- Most abundant
- Sense texture
- Along the centre of the tongue
Describe fungiform papillae
- Along the tip and sides of the tongue
- Sweet, sour, salty
What is the stimulus for salty tastes?
Na+, Cl-
