Taste Is Mostly Smell
Taste and smell are closely linked. The tongue can only differentiate five flavors: sweet, salty, bitter, sour, and umami. But as you eat, odor molecules from the food move through your nasal passages to the olfactory receptor neurons. Each of these is only activated by a specific type of odor, but together, they can convey deeply complex scents and tastes to the brain.
from Crash Course
Key Facts In This Video
All of our senses involve sensory cells that translate stimuli into action potentials, a process called transduction. (0:56)
Scientists estimate that humans can identify about 10,000 different smells. (4:39)
All tastes register on all parts of the tongue—there are no specialized areas for specific flavors. (7:06)