Chemical sense (taste & smell)
Vision reminer
Inner hair cells send to A1
Senses
There are 7 senses, but only cover 4
Chemical senses
Smell (Olfactory) & taste( gustation) are chemical senses
Some nociceptors and thermoreceptors can also be chemical
Why taste & smell?
Help us sort edible and non edible food
sweet more likely to be better, bitter more likely to be poison
Tend to prefer energy and nutrition rich food ( sugar & fat)
Social signaling (both within and in between species
for procreation or mood
Olfactory
How they get into our nose
There are air-born molecules (odorants)
Orthonasaly: From the outside world (going into the nose)
Retronasal: a smell from food already in our mouth
Transduction
Occurs once an outside molecule interacts with an olfactory receptor
Air containing chemicals gets into your nose
Chemical sense (taste & smell) 1
, Chemicals contact the mucosa (dime-sized region at top of the nasal cavity)
Olfactory receptor cells: embedded into mucosa
They have different shape binding sights
10 million with about 400 types
sensitive to different chemical odorents
Transduct chemicals into neural signals
Travel through bone
Cilia embedded into mucus,
Cell bodies supported by epithelium (supporting system )
Axons travel upward through bone
Theories of Olfaction
Shape & docking
We have receptors that pick out and bind specific odorant shapes
Like lock and key hypothesis
Vibration theory
The detection of smell is due to the vibration of molecules
each molecule has different frequencies in the infrared region
Olfactory bulb
Above the bone
where axons connect to
has different structures such as the the glomeruli
receives input from all olfactory nerves
Different types (400) have a specific type of synapse in the glomerulus
Chemotopic: smells that are similar synapse in the same area of the olfactory
bulb
Chemical sense (taste & smell) 2
Vision reminer
Inner hair cells send to A1
Senses
There are 7 senses, but only cover 4
Chemical senses
Smell (Olfactory) & taste( gustation) are chemical senses
Some nociceptors and thermoreceptors can also be chemical
Why taste & smell?
Help us sort edible and non edible food
sweet more likely to be better, bitter more likely to be poison
Tend to prefer energy and nutrition rich food ( sugar & fat)
Social signaling (both within and in between species
for procreation or mood
Olfactory
How they get into our nose
There are air-born molecules (odorants)
Orthonasaly: From the outside world (going into the nose)
Retronasal: a smell from food already in our mouth
Transduction
Occurs once an outside molecule interacts with an olfactory receptor
Air containing chemicals gets into your nose
Chemical sense (taste & smell) 1
, Chemicals contact the mucosa (dime-sized region at top of the nasal cavity)
Olfactory receptor cells: embedded into mucosa
They have different shape binding sights
10 million with about 400 types
sensitive to different chemical odorents
Transduct chemicals into neural signals
Travel through bone
Cilia embedded into mucus,
Cell bodies supported by epithelium (supporting system )
Axons travel upward through bone
Theories of Olfaction
Shape & docking
We have receptors that pick out and bind specific odorant shapes
Like lock and key hypothesis
Vibration theory
The detection of smell is due to the vibration of molecules
each molecule has different frequencies in the infrared region
Olfactory bulb
Above the bone
where axons connect to
has different structures such as the the glomeruli
receives input from all olfactory nerves
Different types (400) have a specific type of synapse in the glomerulus
Chemotopic: smells that are similar synapse in the same area of the olfactory
bulb
Chemical sense (taste & smell) 2
