Taste And Smell (9) Flashcards
We have two senses for detecting chemical stimuli
Taste and smell
Salty taste indicates the presence of
Sodium
5 basic taste qualities
Salty
Sour
Sweet
Bitter
Umami - meaty, brothy or savoury (assoc w/ MSG)
Red dots on the surface of the tongue
Fungiform papillae
What do papilla contain
Taste buds which contain taste receptors
4 different papillae the tongue contains
Filiform
Fungiform
Foliate
Circumvilliate
Filiform
Shaped like cones and located over entire surface - no taste buds
Fungiform
Shaped like mushrooms and found on sides and tip of tongue
Foliate
Series of folds on back and sides
Circumvilliate
Shaped like fat mounds in a trench located at back
Where are taste buds located
In papillae (except for Filiform which mediates touch)
Approximately 10,000
Receptor cells send information to the brain through 3 different nerves ***
Facial nerve - from front and sides of tongue
The glossopharyngeal - from back of tongue
The vagus - from mouth and throat
Where do the 3 cranial nerves for taste connect to
The nucleus of the solitary tract in the spinal chord
2 areas in the frontal lobe the taste cranial nerves connect to **
Insula
Frontal operculum cortex
Olfactory mucosa
The mucus membrane that contains the cilia of the olfactory receptors
The membrane is located at the roof of the nasal sinus, just under the base of the brain
Olfactory bulbs
The structures at the base of the brain, containing the neural circuits that process olfactory information
These neurons receive information directly from the axons of the olfactory receptors
How many types of olfactory receptor neurons
About 350 in humans
Macrosmatic
Having a keen sense of smell that is necessary for survival
Microsmatic
A less keen sense of smell that is not crucial to survive (humans)
Why have researchers found it difficult to map perceptual experience onto physical attributes of odorants
Language issue
Lack of any clear structure-function relationship - some molecules that have similar structures smell different
Flavour
A combination of taste, smell and other sensations
Where are responses from taste and smell first combined
OFC
OFC also has input from the primary somatosensory cortex (hot/cold/spicy) and the lower temporal cortex (the visual ‘what’ pathway)
