The Chemical Senses: Smell
	Smell (Olfaction) operates much like the sense of taste.  The physical stimuli are chemical substances carried in the air that are dissolved in fluid, the mucus in the nose.
	Olfactory receptors are called olfactory cilia and are located in the upper portion of the nasal passages.
	The olfactory receptors synapse directly with cells in the olfactory bulb at the base of the brain.  Olfaction is the only sense, therefore, that is not routed through the thalamus.
	Odors are not easily classified, and primary odors have not really been delineated.  Humans can distinguish among about 10,000 odors but for some reason have a hard time attaching names to odors quite frequently.
	Females are tend to be more accurate than males on odor recognition tasks.