Sense of Smell How it WOrks and why the process

The sense of smell, also known as olfaction, is the ability to perceive odors. It's made possible by the olfactory system, which includes sensory cells in the nose and brain.

3. Introduction to Sense of Smell

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importance. As adults, we can distinguish around
(SO, 10,000 different smells.
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5. The Olfactory Epithelium
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Function
Acts like the taste buds of your nose. Odor molecules dissolve in mucus and bind to olfactory receptor cells.

Comparison with Animals

The size of the olfactory epithelium can indicate the sensitivity of an animal's sense of smell. For example, a dogs
olfactory epithelium is 20 times bigger than a humans.

Unknowns
Scientists are unsure why the olfactory epithelium is pigmented.

6. Differentiating Smells

40 Million Receptor Neurons

The brain has 40 million different olfactory receptor neurons,
allowing it to detect a broad array of smells through
different combinations.

Neuron Replacement

Olfactory neurons are unique in that they are regularly
replaced every 4 to 8 weeks.

7. Smell Pathway to the Brain

Direct Route

Smell signals travel directly to different brain regions, unlike
sight and sound, which are first relayed to a center in the
cerebral hemisphere.

Brain Regions Involved

The signals make stops in the amygdala, thalamus, and
neocortex, triggering responses such as fight or flight,
memory recall, or salivation.

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Smell and Taste Connection Al fa

Taste is closely related to smell Without the ability fo smell, one loses the ability to taste anything beyond
the five basic tastes detected by taste buds: sweet, salty, bitter, sour, and savory,

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