The Neuroscience Center

sound is the perception of changes in air pressure and sight the perception of light, tastes and smell are the perception of chemicals in the air or in our food.

food “tastes” different when the sense of smell is impaired. what is really being affected is the flavor of the food, or the combination of taste and smell.

 

Taste itself is focused on distinguishing chemicals:

1. sweet

2. salty

3. sour

4. bitter

5. umami

 

Tastants are detected by taste buds, back of the mouth, palate, epiglottis.

 

Every person has between 5,000 - 10,000 taste buds.

Each TB consists of 50 - 100 specialized sensory cells, which are stimulated by tastants (sugars, salts, or acids) 

 

When the sensory cells are stimulated -> signals transferred to end of nerve fibers, which send impulses along cranial nerves to taste regions in the brainstem.

 

The impulses -> thalamus and -> cerebral cortex, which makes us conscious of the perception of taste.

 

Airborne odor molecules, called odorants, are detected by specialized sensory neurons located in olfactory epithelium

 

Axons of these sensory cells pass through perforations in the overlying bone and enter two elongated olfactory bulbs lying against the underside of the frontal lobe of the brain.

 

Odorants stimulate receptor proteins found on hairlike cilia at the tips of the sensory cells, a process that initiates a neural response.

 

1. An odorant acts on more than one receptor, but does so to varying degrees.

2. Similarly, a single receptor interacts with more than one different odorant, though also to varying degrees.

    ∴ each odorant has its own pattern of activity, which is set up in the sensory neurons.

 

This patterned activity is then sent to the olfactory bulb, where other neurons are activated to form a spatial map of the odor.

 

Neural activity created by this stimulation passes to the primary olfactory cortex to orbital part of FL

 

Olfactory information then passes to adjacent parts of the orbital cortex, where the combination of odor and taste information helps create the perception of flavor.