Intro to Chemical Senses Taste & Food Choice

1. Explain why it is only partly true to say the tongue is a muscle. The tongue is made up of GROUPS of muscles. Some tongue muscles are inside the tongue, make up most of the mass of the tongue, and shape and move the tongue. Other tongue muscles begin outside the tongue with only terminal (ending) fibers inside it, and control its movement.

2. What does the tongue do when you chew? Moves food around in your mouth Pushes food to the back to be grinded by teeth

Directs small amounts of food into the esophagus 3. What’s the tongue’s job once the food is chewed and mixed with saliva? Directs small amounts of food into the esophagus

4. Can you really “swallow” your tongue? Explain. No, the entire tongue is anchored firmly to the bottom of your mouth. What really happens? The muscles that control the tongue relax and the tongue can fall back, blocking your airway.

5. When you look at your tongue in the mirror you can see raised areas or “bumps”. What are these raised areas called? Papillae

6. Name and describe the 3 types of papillae. Fungiform: mushroom shaped Foliate: leaf shaped Circumvallate: shaped in a V

7. Describe the two functions of papillae Help grip and move food around House taste buds

8. So, can you actually see taste buds with the naked eye? Explain. Taste buds are collections of cells on papillae and can not be seen with the naked eye.

As a person ages, the number of taste buds decreases 9. What is the difference in the structure between a younger person’s tongue and an older person’s tongue? How does this affect the sense of taste? As a person ages, the number of taste buds decreases As a result, sensitivity to taste decreases

10. Name the 5 types of taste. Sweet Salty Bitter Sour Umami (savory, meaty)

11. Explain the relationship between microvilli and taste buds. Taste buds are made of taste receptor cells Taste receptor cells have microvilli Sensitive, microscopic hairs on taste buds Send chemical signals to brain The brain interprets the signals and identifies the taste

12. Where do you actually determine the “taste” of a food? Brain

13. How can the sense of taste protect you from harm? Your brain recognizes the taste as a “bad” one and will reject Long believed that bitter taste evolved as a defense mechanism to detect harmful toxins in plants

14. What can make your taste bud receptors less sensitive? Cold food or drinks Repeated exposure

15. What does saliva do to help you taste? Breaks down, mixes and lubricates foods Ability to be swallowed Transports broken down products to the taste pores It is difficult to taste anything if the mouth is dry

16. Does your tongue ever stop working? Explain. No, even when you are sleeping it is directing saliva to be swallowed.

Taste and Nutrition? People with taste disorders might not be able to enjoy the fun of eating (lower quality of life) and are at risk for other health problems, such as poorly balanced nutrition. Some taste bud research deals with people who have lost their sense of taste, who typically lose weight and become malnourished.

Taste Disorders Ageusia (complete taste loss), hypogeusia (partial taste loss), and dysgeusia (persistent abnormal taste). Nerve damage, and mineral deficiencies can cause this

Can smoking affect the structure of a person’s tongue? Can dull and reduce the number of taste buds Quitting smoking and weight gain?

Acquired Taste Repeated exposure may make a disliked food less disliked

Taste Facts February 2005 was the first time scientists were able to grow taste buds outside the body and keep them alive for months. Just missing breakfast makes you more sensitive to sweet and salty tastes. “Things taste better when you’re hungry” Taste sensitivity is genetic. Bitter taste is extensively studied.

1. What substance is detected by the taste called “umami”? The amino acid glutamate and glutamate compounds Monosodium Glutamate (MSG) Common in Asian dishes, especially Japanese Example: Soy sauce

2. When you look at your tongue you see_____________, and they are made up of __________ ____________ which are made up of even smaller structures called___________ ___________.

2. When you look at your tongue you see PAPILLAE, and they are made up of TASTE BUDS which are made up of even smaller structures called MICROVILLI.

Approximately every 10-15 days 3. How often does your body replace receptor cells? What happens to this replacement schedule as a person ages? Approximately every 10-15 days This turnover rate decreases with age, and therefore taste sensitivity or “sharpness” decreases

5. Besides your tongue, where else are taste buds found? Epiglottis, Esophagus Places where there is contact with food

6. What are olfactory receptors and how do they affect your ability to taste? Area inside of the nose that contain special cells that detect odors and send signals to the brain to identify the smell

7. Explain the difference between a taste and a flavor? Taste: the detection and identification of sweet, salty, bitter, sour Flavor: Flavor is determined by the aroma (smell), taste (sweet, sour, salty or bitter quality), texture, temperature and spiciness (or irritation) of food and beverages. All of these sensory experiences together form "flavor.”

Smell Facts Scientists have found that the sense of smell is most accurate between the ages of 30 and 60 years. Women of all ages are generally more accurate than men in identifying odors. Seventy to seventy-five percent of what we perceive as taste actually comes from our sense of smell. The average person can discriminate between 4,000 to 10,000 different odor molecules. To identify the smell of a rose, the brain analyzes over 300 odor molecules. 1 in 1,000 people are insensitive to butyl mercaptan, the stinky smell of skunks.