A dog has hundreds of millions of olfactory cells to help him analyze smells

airflow enters a regionfilled with highly specialized olfactory receptor cells,several hundred millions of them,compaired to our five million.And unlike our clumsy way of breathing in and out through the same passage,dogs exhale through slits at the side of their nose,creating swirls of air that help draw in new odor molecules and allow odor concentration to build up over mulitple sniffs.But all that impressive nasal architecture wouldn't be much help without something to process the loads of information the nose scoops up.And it turns out that the olfactory system dedicated to proessing smells takes up many times more relative brain area in dogs than in humans.