Come Smell The Roses...

Chemoreception
Chemoreception is the ability to distinguish between specific molecules. It includes the gustatory receptors or the sense of taste and the olfactory receptors or the sense of smell. Chemoreception is most developed in certain insects and animals. Humans, however, have less developed sense of smell and taste. For example, dogs have an excellent sense of smell while male moths have very sensitive and complex chermoreceptors on their antennae to pick up scents produced by the females.

The sense of smell
Olfaction in primates, including us, is poorly developed. Chimpanzees have almost the same sense of smell as us humans. The receptors are found in the olfactory epithelium with olfactory hairs, modified cilia, sticking out from the epithelium. Some specialized olfactory receptors synapse with neurones of the olfactory bulb, which is an extension from the brain. Hence the stimuli in the form of smells are picked up and transmitted directly to the brain via the olfactory bulb.

On to the other senses:
touch
taste
hearing
sight