Gustation (Taste)
By: Elizabeth, Mary, & Emma
Gustation
● The technical terminology for taste.○ Aka. the reason why we believe cookies to be amazing
● 5 Major parts of taste + 2 bonus tastes○ Sweet○ Salty○ Bitter○ Sour○ Umami
■ Water■ Metallic
What’s Umami?~ The taste of savor/ protein.
Sweet Tastes
● Common belief is that sweeter tastes come only from fructose, glucose, or lactose.
○ Other proteins and amino acids can activate the sensory cells in reaction of a “sweet taste”
■ Ex) M
https://www.ncbi.nlm.nih.gov/books/NBK279408/
Sour Tastes
● Sour tastes are caused by H+ ions splitting off by an acid dissolved in a watery solution.
○ Ex) L J O A
Salty Tastes
● Mrs. Stanton, why are you so salty? ○ Did Roddy put some extra magnesium, potassium, or sodium-chloride in
your salad dressing?
Because when your experiencing a salty taste, your receptors are often picking up not only that table salt on your french fries from lunch, but it will also be triggered from foods/ drinks with high amounts of mineral salts (potassium and magnesium) contents.
Bitter Tastes
● Brought together through evolution○ There are about 35 different proteins found within the sensory cells
responding at once to respond to a bitter taste. ○ Evolutionary, many plants developed a bitter taste or poison, this
tactic not only keeps the bugs away, but helps save the human race from eating that leaf that definitely is NOT lettuce.
Umami
● Think of a big, juicy, sizzling, steamy, buttery, fatty, steak.
○ You not only have began drooling, but also recall the taste of Umami.■ Caused by glutamic or aspartic acid, two amino acids found in a
variety of food and plants.● Ex) R T , , , .
Basic Anatomy of Taste
A. PapillaB. TongueC. Taste Receptors D. Taste BudsE. Gustatory CellsF. Taste Pores G. EpiglottisH. Water ReceptorsI. Gustatory CortexJ. Basal Epithelial
Cells
https://www.youtube.com/watch?v=8pCSVtwAZpE
K. Saliva
Papillae
● Raised bumps that contain the taste buds○ Vallate: lie on the back of the palatine section in a V-shaped; you
have a set about 7-12, back towards the throat○ Foliate: 2 groups on each side of the tongue, in front of the V of
the vallate○ Fungiform: respond to both sweet and sour tastes, scattered around
the tongue but more at the tip and sides
Tongue
● Muscular organ attached to the
floor of the mouth
● moves food while chewing and aids in swallowing
● helps to facilitate speech
● hosts papillae for taste
Taste Receptors
● Found in taste receptor cells on tongue and in upper digestive system
● Binding of neurotransmitters to the associated sensory dendrites triggers generator potentials that evoke action potentials in the fibers
● Taste receptors completely adapt in 1-5 minutes
Taste Buds
● The Sensory organs for Taste○ Location: Tongue- more specifically Fungiform Papillae, soft plate,
inner surface of cheeks, pharynx, and epiglottis.○ Number varies amongst each Papillae
■ Contains 50- 100 Epithelial Cells
Gustatory Cells
● Also known as taste receptor cells● Cells in the taste buds that activate the vagus nerve● Stimulated by the chemical makeup of solutions and
responds to the primary tastes ● When a stimulus activates a gustatory cell, an electrical
impulse will be sent to the cerebral cortex● The brain will interpret this as taste
Taste Pores/Gustatory Pores
● Located on top of taste receptor cells ● Parts of the food dissolved in the saliva come into
contact with the taste receptors via the taste pores
Epiglottis
● A flap of cartilage located at the end of the tongue by the throat and in front of the larynx
● Keeps food from entering the windpipe and lungs● Closes during swallowing to make sure that food is not
directly inhaled● Epiglottitis: when the epiglottis is swollen and causes
severe breathing difficulty
Water Receptors
● Tongues “taste” water by sensing sour taste○ Generally cause the difference in our perceptions on waters “taste”
● https://www.sciencenewsforstudents.org/article/tongues-taste-water-sensing-sour
Gustatory Cortex
● Brain structure located in the cerebral cortex responsible for the perception of taste found on the border of the anterior insula and frontal operculum
● Works with the taste buds to create the sensation
Basal Epithelial Cells
● Taste bud cells are subject to friction and are burned by hot foods
● They are replaced every 7-10 days and are the most dynamic
● Act as stem cells● Divides and differentiates into new gustatory epithelial
cells
Saliva
● Primary external fluid in taste receptor cells● Plays a role in taste sensitivity● Transport of taste substances to the taste receptor and
protection of the taste receptor● In order for food to have taste, it must first dissolve
in saliva
Pathway of TasteFirst 2/3 of the tongue:
taste receptors in taste buds →
chorda tympani of facial nerve
(CN VII) → solitary tract in
medulla → posteromedial ventral
nucleus→ thalamus → primary
gustatory cortex (taste processed)
Throat, palate, and back 1/3 of tongue:
taste receptors in taste buds →
glossopharyngeal nerve (CN IX) &
vagus nerve (CN X) → solitary
tract in medulla → posteromedial
ventral nucleus → thalamus →
primary gustatory cortex
Ageusia
Ageusia is the total lack of sense of taste.
It can be caused by:
● tissue damage to the nerves of the tongue● damage to the taste buds
○ example: long-term tobacco use
Phantogeusia
Phantogeusia is the creation of phantom tastes, or gustatory hallucinations. People with phantogeusia experience tastes (often metallic, bitter, or salty) without a stimulus.
The cause of phantogeusia is not clear, but it is thought to maybe be a result of nerve damage, damage to the ears, medication, aging, etc.
Works Cited
https://courses.lumenlearning.com/austincc-ap1/chapter/special-senses-taste-gustation/
https://www.ncbi.nlm.nih.gov/m/pubmed/14964052/
https://www.innerbody.com/image_nerv12/nerv125.html
http://www.virtualworldlets.net/Resources/Hosted/Resource.php?Name=SensoryMalfunctionTaste
https://health.howstuffworks.com/human-body/parts/tongue2.htm
http://jcda.ca/article/d86
Works Cited
https://explorable.com/neural-pathways-of-smell-taste-and-touch https://www.neuroscientificallychallenged.com/glossary/gustatory-cortex
Activity
In this activity, we ask you to blindfold yourselves and undergo a “taste test”. Essentially everyone will get a sample of each food that evokes the response of each major taste.
Additionally, you’ll be getting 2 mini cups of water from two different sources. This will help you recieve the responses from the water receptors on your tongue.
Activity
The Goal:
Identify each of the 5 tastes, and receive a better first hand experience with each individual taste.
Materials:
● 1X sample of each food● 2 X cups filled with
different waters● 1 x paper and pen● 1 X blindfold● 1 x Partner
Activity Steps: 1. Make a table consisting of the 5 main tastes, and a
blank box. Here you will write which food that belongs to.
2. 1 Partner will blindfold the other 3. The partner who is blindfolded will taste each food 1
at a time, and tell the other partner which box it belongs in.
4. Non-blindfolded partner will recall each of the detected foods.
5. Switch Roles 6. Compare Results to Actual Results depicted by
presenters
Activity
Taste: Food:
sweet Milk chocolate nugget
salty pretzels
unami Salami and cheese
sour Sour patch kids
bitter Unsweetened chocolate