DetailsSmell and taste are interconnected as senses, and they use the same type of receptors. Inputs from each sense combine in the back of your throat to create unique representations of stimulus based on both taste and smell. If smell is not functional, taste will be severely impacted as well. Humans can distinguish five primary tastes, but they can sense up to 10,000 different odors.
Smell & Taste Fact SheetCheck out the fact sheet on smell and taste on the left, provided by the Dana Foundation.
ChemoreceptorsThe chemoreceptors in the nose are called olfactory receptors, and they respond and bind specifically to each odorant's stimulus. Humans have 12 million olfactory receptors in the nasal cavity, and they send stimulus to the olfactory bulb
Chemoreceptors in the tongue, called gustatory receptors or taste cells, are arranged in groups called taste buds. Each primary taste sensation corresponds to one type of gustatory receptor, exciting specialized neurons. |
The Nose and Mouth |
Vision Pathway |
The eye is a light-detecting organ that sends signals based on visual stimulus to the brain through the optic nerve. It enables us to differentiate colors and depth, and it contains a sheet of photoreceptors in the retina. Below is a diagram of the eye.
Additional ResourcesCheck out these links for more information about smell and taste!
Boundless Biology: courses.lumenlearning.com/boundless-biology/chapter/taste-and-smell/ courses.lumenlearning.com/austincc-ap1/chapter/special-senses-taste-gustation/ |
Olfactory Pathway: When olfactory receptors detect stimulus in the mucous membrane in the nasal cavity, it sends the signal through olfactory nerve fibers to the olfactory bulb in the brain. The olfactory bulb sends signals to the cortex of the pyriform lobe near the temporal lobe, bypassing the thalamus. Extensions of the olfactory cortex also correspond to regions involving memory and emotion, which explains why memories are often triggered by smell.
Gustatory pathway: After taste sensations are picked up by gustatory receptors, they send signals through sensory nerves and cranial nerves (facial and glossopharyngeal nerves) to the medulla, thalamus, and primary gustatory cortex in the parietal lobe.
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