Ask A Scientist© Veterinary Topics Archive

name         Brett L.
age          12


Question -   What percent of a dogs brain is used
 for smelling... And how much better is it than a humans?
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Hi Brett!
Quite a nice question and i will try to answer
even i am not an specialist.
The brain of our dogs is very similar in design and
action as other mammals.
The higher vertebrate brain consists of different
parts as the cerebrum and the cerebro-spinal system.
The changes in the development of the brain reflect
the evolution of organisms, for ex. in fishes the
optic lobes are highly developed. In primates and
mostly in man, the cerebrum is greatly expanded and
much more convoluted (wrinkled) leading  to greater
power of reasoning, concentration and appreciation.
The brain consists of billions of cells called
neurons, that communicate through neurotransmitters.
The cerebrum  is the  control center  of the brain, it
controls learning, emotions, behavior.
The cerebro-spinal system allows for the functions of
senses: touch, taste, smell, hearing, sight.
The two senses more developed in the dog are smell and
hearing.
The dogs brain in large part is dedicated to smell.
Dog´s world is a world of scents. Its nasal passages
are arranged to allow a greater volume  of air to be
drawn over the sensitive lining than in the case of
men.
Besides that dogs have sensory cells in their noses
that respond to chemicals in the air.
Rapid sniffs carry messages to the enlarged olfactory
centre in the brain where the scents are analyzed and
cataloged.
Most breeds have over 200 million scent receptors in
comparison to humans which have 5 million.

From a practical point of view, there are some great
advantages of dogs over other animals for odor tasks
like landmine detection. Dogs take instructions
readily from humans, they learn very quickly, and they
are quite adaptable to different situations and
environments.
 Hope that answers in a way your question.
Come back when you need!
And thanks for asking NEWTON!

(Dr.) Mabel Rodrigues
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