The chemical senses Flashcards
Where are the taste organs?
Tongue
Cheeks
Soft palate
Pharynx
Epiglottis
What are the 4 types of lingual papillae?
Filiform
Foliate
Fungiform
Circumvallate
Structure and function of filiform
Spiked
- No taste buds
- Sense texture
Structure of foliate
Ridges
Structure of fungiform
Mushroom like
Structure of circumvallate
Large pimples
- Contain half of all taste buds
How does sensory transduction occur?
Taste pores allow sensory transduction via microvilli
Which taste sense use ion channels?
Salty - ENac
Sour - OTOP1
Which taste senses use G-protein coupled receptors?
Bitter - T2Rs
Sweet - T1R2 + T1R3
Umami - T1R1 + T1R3
How many types of stimuli do taste cells respond to?
1
How many types of stimuli do taste buds respond to?
Taste buds contain taste cells which respond to various stimuli
How big is the olfactory epithelium?
10cm2
What are the 3 components of the olfactory system?
Olfactory bulb
Olfactory cortex
Olfactory epithelium
What are olfactory receptor cells?
Bipolar chemoreceptive neruons
what happens to odorants in order to reach olfactory receptor cells?
Odorants must dissolve in the mucus layer
Why are olfactory receptor cells different to most adult neurons?
They are replaced regularly
How many odorant receptors are expressed on 1 olfactory receptor?
1
How does transduction occur via G olfs?
G olf ->
Adenylyl cyclase ->
cAMP ->
Cyclic nucleotide gated ion channels ->
Depolarisation ->
Ca2+ gated Cl- channels cause further depolarisation
What can a large enough receptor potential cause?
Reaching the threshold to fire an ap
How many olfactory receptors can each glomerulus receive input from?
1
