Smelly Facts Much of the thrill of kissing comes from smelling
the unique odors of another's face. By simply smelling a piece of
clothing, most people can tell if a woman or a man had been wearing
it. Each of us has an odor that is unique, just like our
fingerprints. Women have a keener sense of smell than men do.
According to some sources, the stethoscope was invented not to hear
the heartbeat better, but to give doctors some distance from a
patient's bodily odors. Taste is closely related to smell, in fact,
taste is thought to be roughly 80% smell.
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More Smelly Facts Smells stimulate memory. Students given
olfactory stimulation along with a word list retain much more
information and remember it longer. A smell can trigger very strong
memories, positive and negative. Many smells are heavier than air
and can be smelled best at ground level. We smell best if we take
several short sniffs, rather than one long one. Moths can identify
a single molecule by its smell. Dogs can distinguish non-identical
human twins by smell, but not identical ones. Dogs can smell some
cancers in people.
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What do we call it? The smells of a rose, perfume, freshly
baked bread and cookies...these smells are all made possible
because your nose and brain work together. As with other senses,
the sense organ receives a stimulus and sends information to the
brain. The brain processes, perceives, and interprets this
information. The sense of smell is called olfaction. Anosmia is the
medical term for the complete loss of your sense of smell.
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The Olfactory Apparatus: parts of the nose involved in smelling
http://www.mhhe.com/socscience/intro/ibank/set1.htm
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It all starts with molecules Odors are just small molecules
that drift through the air into your nasal cavity through the
nostrils and mouth. An object will have no odor unless its
molecules can break free from the object and enter the air. Rocks
have little smell.why? Awaiting the molecules is the olfactory
apparatus, which includes all the parts of the nose involved in
smelling.
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How you smell: the big picture. http://www.exploratorium.edu/
cooking/seasoning/taste/smell. html
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Once in the nasal cavity Odor molecules first dissolve in nasal
mucus. The molecules then connect to hairs on olfactory receptor
cells in the olfactory membrane. Receptor cells work with certain
smell types. About forty of these cells must detect odor molecules
before a smell can be identified by your brain. Receptor cells send
nerve signals to the olfactory bulb, a large nerve extension from
the brain. Signal moves from bulb to brain by olfactory nerve.
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Some vocabulary terms you ought to know... The olfactory
membrane is equivalent to the retina. The olfactory receptor cells
are equivalent to the rods and cones, or the hair cells in the
cochlea of your inner ear. Olfactory Bulb Olfactory membrane
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Smell, emotion, memory, and brain. The olfactory nerve carries
the smell signal to the limbic region of the brain, where emotion
and emotional memory are processed. The signal then goes to the
cortex for perception and interpretation. Smell has a sort of
privileged access to our subconscious.
http://www.cf.ac.uk/biosi/staffinfo/jacob/teaching/sensory/olfact1.html#Limbic%20system
http://www.cf.ac.uk/biosi/staffinfo/jacob/teaching/sensory/olfact1.html#Limbic%20system
Smell is our most ancient of senses.
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Dogs: they can smell well, but.
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How come dogs have a better sense of smell than humans? Dogs
have much larger olfactory membrane. Postage stamp size vs. size of
a small plate Dogs have way more receptor cells. 12 million cells
vs. 200 million cells Dogs have more types of receptor cells. 500
types vs. thousands of types Dogs are able to distinguish more
odors 10,000 odors vs. millions of odors
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A dogs nose The wet snout catches and dissolves odor
molecules.
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Taste and Tongues Watch out for this! Five tastes, not four.
You can taste all flavors all over your tongue. Sweet, salt, sour,
bitter, umami
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This old tongue map is out of date now.
http://www.livescience.com/health/06082 9_bad_tongue.html
A little on taste Molecules of food stimulate taste receptor
cells to send messages to your brain. The sweet, salty, and umami
buds are the least sensitive and the bitter and sour ones are the
most sensitive. Taste bud
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Taste apparatus parts The tongue is covered with visible bumps
called papillae. These bumps are covered with microscopic taste
buds. Taste buds are covered with receptor cells. Receptor cells
are covered with sensory fibers that interact with taste molecules.
Molecule shape determines what tastes the fibers interact with.
Sort of like a key (taste molecule ) fitting in a lock
(fiber).
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The taste process The tongue has Papillae (bumps) which have
Taste buds which have Taste receptor cells that have Sensory fibers
(hairs) that send Signals along a nerve to the Brain which
perceives and interprets information.
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Snakes and smell Snakes use their Jacobson's Organ. located in
front of the roof of the snake's mouth, functions as an odor
receptor. The forked tongue snares molecules in the air, which
dissolve in the moisture of the snake's tongue. (like a dogs snout)
it inserts the tips of the forked tongue into the two awaiting
openings of the Jacobson's organ where the particles are identified
and analyzed.
