Send the link below via email or IMCopy
Present to your audienceStart remote presentation
- Invited audience members will follow you as you navigate and present
- People invited to a presentation do not need a Prezi account
- This link expires 10 minutes after you close the presentation
- A maximum of 30 users can follow your presentation
- Learn more about this feature in our knowledge base article
Chemical Senses Smell & Taste
Transcript of Chemical Senses Smell & Taste
Gustation: Tasting the World
Tastebuds are the common name for our taste receptor cells. These specialized neurons are responsible for gustation, the sense of taste.
Most are located on the tongue but we also have taste cells on the roof of the mouth, the cheeks, and under the tongue as well. An average person has around 500 taste buds. Some people however have as many as 10,000. These people are known as "supertasters"
. As a result they need far less seasoning than most.
Supertasters taste buds
Each of the bumps on your tongue contains multiple taste buds.
Each of those taste buds has around 20 chemical receptors, similar to those found in synapses. The chemicals in the food you eat react with these receptors causing the taste nerves to fire.
Why do we like certain tastes?
Generally speaking people tend to favor certain favors like sweetness, and not like some flavors like bitter. Why might this be? What influences the tastes we like?
Taste buds only last around 10 to 14 days before being replaced.
The constant use and abuse causes them to wear out quickly. Part of what you are cleaning off your tongue when you scrub it are dead cells.
The 5 Basic Tastes
In 1916 German psychologist Hans Henning proposed 4 primary tastes, salty, bitter, sweet, and sour.
However, in 1996 a 5th taste was added called Umami (A Japanese word used to describe a meaty or brothy taste) Umami is actually glutamate
. This is the reason the seasoning MSG (monosodiumglutamate) makes food taste nice.
The 5 tastes combine with the texture, temperature, smell, and "heat" of the food to create every taste we are capable of sensing
. Also despite what many people think certain tastes are not processed on specific areas of the tongue.
The Sense of Smell
Like taste, the sense of smell is based around chemicals. This ability for your nose to detect chemicals is called olfaction
. The actual part of the body responsible for smelling is located deep within the structure of the nose and is only around a square inch in each nasal cavity, but has around 10 million olfactory receptors.
The olfactory receptors look similar to hairs and trap odor molecules as they pass through the nose. Once they are trapped it triggers that neuron to fire.
From there the impulse has a direct route into the olfactory bulb, and doesn't have to follow the thalamus pathway like the other senses
. This different pathway also allows the sense of smell to bypass the selective attention filter in our brain. There are over 1000 different types of odor receptors in the nose. Like the taste buds, these cells wear out quickly they only last around 5 to 8 weeks before they must be replaced.
Why might the sense of smell have this direct route to the brain?
Some studies show that women have a superior sense of both taste and smell, why might this be?