by Lily Maltz, Olivia Kennis, Emma Loeb, Lindsey Walters, and Dana Kapeller-Libermann

Purpose of taste is to motivate us to eat some substances and avoid eating others

Parts of Taste• Apex: tip of the tongue • Filiform Papillae: coating that gives the tongue a cleaning

and rasping action o supported with help of the antibacterial parts of salivao sensitive to sour taste

• Foliate Papillae: 2 groups on either side of the tongueo taste buds on their surfaces

http://www.doctorspiller.com/images/OralAnatomy/Tongue2.jpg

Parts of Taste Continued• Fungiform Papillae: involved in taste sensation

taste buds on their surfaces respond to sweet and sour tastes concentrated at tip of tongue and sides of tongue spherical body with flattened top and narrow base

• Vallate Papillae: have taste buds on their surfaceso taste buds are on outer walls of "keep" and inner and

outer banks of "dike"o secretory glands produce watery mucus that surrounds

taste budso sensitive to bitter tastes

Taste Buds• Each bud contains between 50-150 receptor

cells• 2,000-10,000 taste buds• allow us to enjoy food and warn us of danger 

http://www.eatologies.com/wp-content/uploads/2009/02/709px-taste_budsvg-300x253.png

http://www.vivo.colostate.edu/hbooks/pathphys/digestion/pregastric/taste.html

Sweet•Humans have evolved to enjoy the "sweet" taste.•Sugars from fruits are needed because they are a valuable source of energy and growth.•Sweet receptors recognize hydroxyl groups (OH).•"Honey is sweet because we like it, not we like it because honey is sweet“•Dan Dennett•Look for the answers in your brain, not in the glucose.•Cake is a supernormal stimulus

http://holidays.thefuntimesguide.com/2008/11/leftover_halloween_candy.php

http://howmanycaloriesshouldieatadayinfo.com/how-many-calories-in-fruit/

Salty

•"salty" taste occurs when saliva breaks down sodium (Na+)•salt tastes pleasant to humans•necessary to maintain a balance of salt in bodily fluids

http://www.nytix.com/Blog/newyorkcity/uploaded_images/Salty_Snacks-788280.jpg

http://wellnessrounds.org/wp-content/uploads/2011/10/SaltShaker.jpg

Sour

http://www.bangstyle.com/wp-content/uploads/2011/09/lemons.jpg

http://teachinggoodthings.com/blog/teaching-gratitude-and-a-challenge/

• Sour molecules permeate taste cells directly through channels in the walls

• Evoked by acids in dilute solutions• Hydrogen ions activate taste receptors and

lead to a sour sensation• Unpleasant experience through natural

selection

Bitter• Things taste bitter because

chemical substances are able to bind to one or another of the 50 to 80 different types of receptor sites located on bitter receptor cells  

• Toxic substances often times bitter

• People with more taste buds are more sensitive to taste-- especially bitter

• Young children are more sensitive to bitter tastes than adults

http://www.publicdomainpictures.net/pictures/2000/nahled/1-1226265697kzA8.jpg

http://seanrobsville.blogspot.com/2009/10/three-poisons-of-mind-in-buddhism.html

Umami

• Controversial, and still debated • Taste of L-Glutamate• Receptor is a heteromeric

complex of 2 class C g-protein receptors, T1R receptors, similar to the taste of sweet

• Strong sense of synergism• MSG is used as a

taste enhancer

http://gcnaturalfamilyhealth.com/wp-content/uploads/2011/04/msg.png

Activity

Instructions:1) Touch toothpick to the tip of your tongue.2) Record on a sheet of paper:        a) which taste you are tasting (sweet, salty, sour, bitter)        b) how strongly you tasted it on a scale of 1-5

Objective: See which taste you feel is the most sensitive on the tip of your tongue!

The Tongue Map

http://www.dampier.wa.edu.au/Room13/taste.htm

• Different parts of the tongue have more sensitivity to tasteso Bitter- back of tongueo Salty- sides of tongueo Sour- behind salt sensorso Sweet- front of tongue

Transduction• Taste cells have different transduction methods depending

on the cell• Taste cells respond to chemical stimuli --> depolarization of

membrane at receptor site• Ionic imbalance between inside and outside of receptor cell

creates an electrical potential• Potential causes movement of calcium ions into the cell• Excess of calcium + release of neurotransmitter =

conversion of receptor signal to electrical signal• Electrical signal conveyed to brain

http://www.colorado.edu/intphys/Class/IPHY3430-200/image/10-16.jpg

Transduction continued

•Taste sensory neurons are connected to the limbic system and cerebral cortex.•The primary taste area is located in the rear part of the underside of the frontal lobe.•Taste can connect to several other areas in the cortex including the orbitofrontal cortex.  This is where taste and smell meet, which creates the sensation of flavor.

Threshold• Taste receptors have a very low threshold (the

concentration at which a substance can be distinguished from water)

• The intensity of taste sensation seems to be related to the number of taste cells that respond to the presence of the particular chemical.

http://rutgersday.files.wordpress.com/2010/03/mouth_open.jpg

Taste and Smell Connection

Smell plays a prominent role in how we taste. The taste receptors are almost secondary to smell. Food gives off vapors on the way to your mouth, and more once in your mouth, which travel up the retronasal route. The tighter together one's taste buds are, the stronger the taste he or she experiences. 

http://images.sciencedaily.com/2009/02/090212141149-large.jpg

Disorder

Ageusia - Loss of the sense of taste

Many things can cause aguesia such as:• Upper respiratory and middle ear infections• Radiation therapy for cancers of the head and neck• Exposure to certain chemicals, such as insecticides and some

medications, including some common antibiotics and antihistamines• Head injury• Some surgeries to the ear, nose, and throat • Poor oral hygiene and dental problems• Burning of the tongue - Can heal• Colds

Disorder cont.Burning Mouth Syndrome• Burning sensation on tongue, lips, and throughout the mouth• More occurrent in middle-aged women

Some causes include: • anxiety and depression• damage to nerves that control pain and taste• hormonal changes• dry mouth, which can be caused by many medicines and disorders such

as Sjögren’s syndrome or diabetes• nutritional deficiencies• oral candidiasis, a fungal infection in the mouth• acid reflux• poorly-fitting dentures or allergies to denture materials

Fun Facts•We have almost 10,000 taste buds inside our mouths, even on the roofs of our mouths. •Insects have the most highly developed sense of taste. They have taste organs on their feet, antennae, and mouthparts. •Fish can taste with their fins and tail as well as their mouth. They can taste their prey before they even see it.  Fish use their taste receptors to find and hunt prey.  •In general, girls have more tastebuds than boys. •Taste is the weakest of the five senses.•It is believed that the color red can make someone hungry•You need saliva to be able to taste.•Whether or not someone likes the taste of cilantro is believed to be because of a gene.

http://jssgallery.org/other_artists/andy_warhol/campbells_soup_can.htm

Berry, Michael. "PHYSIOLOGY OF TASTE." SFF Net. 1994. Web. 19 Oct. 2011. http://www.sff.net/people/mberry/taste.htm. "Burning Mouth Syndrome." NIDCR. May 2011. Web. 19 Oct. 2011. http://www.nidcr.nih.gov/OralHealth/Topics/Burning/BurningMouthSyndrome.htm.

"Chapter 10 - Taste and Smell." UNMC | Home.  Web. 25 Oct. 2011. http://www.unmc.edu/physiology/Mann/mann10.html  Dennett, Dan. "Dan Dennett: Cute, Sexy, Sweet, Funny | Video on TED.com." TED: Ideas worth Spreading. Feb. 2009. Web. 20 Oct. 2011. http://www.ted.com/talks/dan_dennett_cute_sexy_sweet_funny.html. Gray, Peter. Psychology. 5th ed. New York, NY: Worth, 2007. Print. Krulwich, Robert. "Sweet, Sour, Salty, Bitter ... and Umami : Krulwich Wonders... : NPR." NPR : National Public Radio : News & Analysis, World, US, Music & Arts : NPR. NPR, 5 Nov. 2007. Web. 19 Oct. 2011. http://www.npr.org/templates/story/story.php?storyId=15819485. "Neuroscience for Kids - Taste." Neuroscience for Kids. Web. 18 Oct. 2011. http://faculty.washington.edu/chudler/tasty.html. "Taste Receptors and the Transduction of Taste Signals - Neuroscience - NCBI Bookshelf." U.S. National Library of Medicine. 2001. Web. 21 Oct. 2011. http://www.ncbi.nlm.nih.gov/books/NBK11148/. "Taste, Physiology of Gustatory Strucures." World of Anatomy and Physiology. 1 ed. 2002. Print.  Wanjek, Christopher. "The Tongue Map: Tasteless Myth Debunked | LiveScience." Current News on Space, Animals, Technology, Health, Environment, Culture and History | LiveScience. 29 Aug. 2006. Web. 19 Oct. 2011. http://www.livescience.com/7113-tongue-map-tasteless-myth-debunked.html. "Your Sense of Taste." ThinkQuest. ORACLE. Web. 19 Oct. 2011. http://library.thinkquest.org/3750/taste/taste.html. Zhang, Feng. "Molecular Mechanism for the Umami Taste Syngerism." JSTOR. 30 Dec. 2008. Web. 20 Oct. 2011. http://www.jstor.org/stable/25465010?&Search=yes&searchText=umami&list=hide&searchUri=%2Faction%2FdoBasicSearch%3FQuery%3Dumami%26acc%3Don%26wc%3Don&prevSearch=&item=1&ttl=108&returnArticleService=showFullText. 

Bibliography