 Specialized receptor cells
of the olfactory epithelium
detect and recognize smells.
Your nose is a huge cavity built to smell, moisten, and filter
the air you breathe. When you breathe in, the tiny hairs, called
cilia, act like a broom and filter
everything trying to get into your nose; from dust particles to bugs.
The air passes through the nasal
cavity and though a thick layer of mucous membrane to the olfactory bulb. The smells are recognized
here because each smell molecule fits
into a nerve cell like a puzzle piece. The cells then send signals
to the brain via the olfactory nerve.
The brain then interprets those molecules as the sweet flowers, or
the curdling milk that you've held up to your nose.
Humans can detect over 10,000 different smells. The olfactory
nerve picks up the scents from the air you breathe and translate
them into nerve impulses or messages that are then sent to the
olfactory bulb located in the front of the brain.
Actually, how and why we smell is still inadequately known. There
are many theories about the exact process of our sense of smell.
Most believe that it is highly specialized processes in which molecular rings and receptors invite
odorant-bringing proteins. It is a very complicate, intricately
detailed, and mysteriously misunderstood system, our sense of
smell.
Did you know?
Dogs have 1 million smell cells per nostril, and their cells are
up to 100 times larger than those of humans.
Anosmia is the condition that makes people
unable to smell.
Your sense of smell directly affects your
sense of taste.
Smell can evoke emotions such as happiness,
fear, even sexuality. |
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note:
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receptor cells: 感受细胞
olfactory epithelium: 嗅觉上皮细胞
cilia: 纤毛
dust particle:
尘粒、微尘
nasal cavity:
鼻腔
mucous membrane:
粘膜
olfactory bulb:
嗅球（嗅叶的球茎状末
梢，嗅觉神经的起步）
smell
molecule: 嗅觉分子
olfactory
nerve: 嗅神经
Anosmia: 嗅觉缺失症
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