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Name: Brett L
Status: Student
Age: 12
Date: 10/1/2003


Question:
What percent of a dogs brain is used for smelling... And how much better is it than a humans?



Replies:
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. DogĀ“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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