Found in the nose and mouth,papilla ie bumps on the tongue contain taste buds down between sweet sour salty and bitter.some act directly by ion channels others indirectly .other taste sensations really smell
smell received in the nasopharynx ,airborne molecules go into solution on moist epithelial surfaces of the nasal passage approximately 1000 gene codes for sensory receptor fried onions odor not one receptor but a mixture of many odors registered in our mind as one,very sensitive habituates rapidly dont smell after a bit hence odor sensation has relatively unfiltered root to higher brain centers,snakes are more chemo sensitive than us
