Taste and Smell Flashcards
What are chemical senses used for?
Used to evaluate potential foods Smell -response to airborne chemicals Taste -response to chemicals in solution in the oral cavity
How do taste and smell work together?
They work in concert which means we can’t taste without smell
What are taste receptors?
Found in tongue, oral cavity, lungs, throat, esophagus
Occurs in cluster of 50-100 to make a taste bud
Replaced every 9-10 days
Microvilli pick up solutes dissolved in saliva
What do gustatory receptors within a taste bud share?
The same afferent neuron
Don’t have their own bacon
What is umami?
Savoury
1 type of gpcr
What is sweet?
2 type gpcr
Gs coupled
What is salty?
No specific receptor
Acts directly on ion channels
What is bitter?
30 type gpcr
What is sour?
Unclear how encoded
Enter through sodium channel and block potassium
What are the 3 gustatory pathways?
Facial
Vagus
Glossopharyngeal
Projections are ipsilateral
What is ageusia?
Inability to taste
-rare with many pathways
What is the olfactory system?
Humans can detect between 1000-4000 odors
Humans are less reliant on odor processing compared to other species
What are the 6 types of scents?
Floral, fruit, spicy, resin, burnt, putrid
Where are the receptor cells of the olfactory system located?
In the upper part of the nose
Receptors are embedded in dendrites in the nasal passage
Open to air
Have 350 types
What is the one receptor one neuron rule?
The receptors are proteins in the cilia membrane
All receptors of the same type project to the same general location in the olfactory bulb
Each receptor type responds in varying degrees to a variety of odors
What is the olfactory mucosa?
Mucus covered tissue
Receptor cells are embedded
What is the cribriform plate?
Axons pass through the porous portion of the skull to form olfactory nerve to olfactory bulb
What are olfactory glomeruli?
Clusters of neurons on the ventral olfactory bulb
Receive input from multiple receptor cells all from the same receptor type
What is the olfactory bulb?
Neurons project via olfactory tract
Project to contralateral structures in the mtl
What are the 2 major olfactory pathways?
Projects to limbic system to mediate emotional responses to scents
Medial dorsal nuclei of the thalamus to orbitofrontal cortex for conscious perception of scents
What is anosmia?
Inability to smell
Blows to head shears olfactory nerves that pass through cribriform plate
