1. THE CHEMICAL SENSES:
SMELL AND TASTE

2. Smell and Taste
✘ Smell and taste are the
chemical senses. These two
senses are mediated quite
differently but they are
perceived together.
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3. Smell
✘ The sense of the smell or olfaction
allows us to detect and to
differentiate the odors.
Odor - a sample of molecules of a
substance in the air. It triggers firing of
receptor neurons in the olfactory
membrane high in each nostril.
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4. Olfactory Nerve - the nerve
that transmits information
concerning odors from
olfactory receptors to the
brain.
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5. ✘ Smell is an important sense as
it can alert us to danger like
gas leak, fire or rotten food but
also is closely linked to parts of
the brain that process emotion
and memory. Unpleasant and
bad smells actually send pain
signals to the brain to warn us
of possible danger.
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6. Taste
✘ The sense of taste or gustation is
sensed through taste cells that is
located on taste buds.
Taste cells - receptor cells that are
sensitive to taste.
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7. Taste buds - the sensory organs for taste;
they contain taste cells and are located
mostly on the tongue.
Flavor - a complex quality of a food and
other substances that is based on their
odor , texture and temperature as well
their taste.
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8. 8
Primary taste qualities:
sweet, sour, salty and bitter.

9. ✘ Buds in the mouth are
evolutionary adaptive
because they can warn of
bad food before it is
swallowed.
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10. End of Presentation