1. Physiology of Taste
Buds
PRESENTED BY: TALHA ZAKRIA
ARID #: 18-ARID-4665

2. Introduction:
• Taste buds are sensory organs that are found on your tongue and allow you to
experience tastes that are sweet, salty, sour, and bitter.
Activity:
• How exactly do your taste buds work? Well, stick out your tongue and look in the
mirror.
• You will see all those bumps? Those are called papillae, and most of them contain
taste buds. Taste buds have very sensitive microscopic hairs called microvilli. Those
tiny hairs send messages to the brain about how something tastes, so we know if it's
sweet, sour, bitter, or salty.

3. Structure: (Papillae)

4. Structure and Location of Taste Buds:

5. Number of Taste Buds:
• The average person has about 10,000 taste buds and they're replaced every 2
weeks or so. But as a person ages, some of those taste cells don't get replaced.
• An older person may only have 5,000 working taste buds. That's why certain
foods may taste stronger to you than they do to adults.
• Smoking also can reduce the number of taste buds a person has.

6. Working of Taste Buds and Role of Nose:
• While you're chewing, the food releases chemicals that immediately travel up
into your nose.
• These chemicals trigger the olfactory receptors inside the nose.
• They work together with your taste buds to create the true flavor of that yummy
slice of pizza by telling the brain all about it.

7. Contd…
• When you have a cold or allergies, and your nose is stuffy, you might notice that
your food doesn't seem to have much flavor.
• That's because the upper part of your nose isn't clear to receive the chemicals
that trigger the olfactory receptors (that inform the brain and create the sensation
of flavor).

9. Types of taste:
• There are five universally accepted basic tastes that stimulate and are perceived
by our taste buds:
1. Sweet
2. Salty
3. Sour
4. Bitter
5. Umami.

10. Taste modalities over tongue

11. Dissolution to Saliva
Attachment to Receptors
Generator Potential
Action Potential
General Pathway of Taste

12. Factors affecting Taste (buds)
• Temperature:
Maximum taste obtained at 30-40oC
• Age:
Decrease in taste sensitivity in older people
• Sex:
Women are more sensitive to sweet and salt and less sensitive to sour
than man.

13. Disorders:
• Ageusia
Loss of sense of taste.
Loss of sense of taste is also a possible symptom of COVID-19
• Hypogeusia
Reduced ability to taste sweet, sour, bitter, or salty things
Heavy smoking, dehydration, radiation therapy administered to the neck or
head, or burns to the tongue that damage the taste buds can all cause a
diminished sense of taste.

14. Your tongue can actually provide clues about your overall health.
A bright red tongue may be a sign of folic acid or B12 deficiency, scarlet fever, or
Kawasaki disease (a serious condition seen in children)
White spots or a white coating on the tongue could indicate oral thrush (a type of yeast
infection), or leukoplakia (which can be a precursor to cancer)
A black, hairy tongue can be a sign of bacterial overgrowth, and can also occur in
people with diabetes or those on antibiotics or chemotherapy
Painful bumps on the tongue may be canker sores (mouth ulcers), or oral cancer

15. Loss of Taste and Covid-19:
• COVID-19 typically produces a range of flu-like symptoms, including a cough
and fatigue, but it can also cause the loss of taste and smell. Taste and smell
can return or get better within 4 weeks of the virus clearing the body, but it may
sometimes take months for them to improve
• A 2020 meta-analysis observed that 53% of people who contracted COVID-19
had problems with taste and smell.

16. Problems with Taste buds:
• There are several diseases in which usually taste buds are affected:
1. Obesity
2. Covid-19
3. Diabetes
4. High blood pressure
5. Poor nutrition
6. Nervous system diseases

17. References
• Schiffman SS, Gatlin CA. Clinical physiology of taste and smell. Annu Rev Nutr. 1993;13:405-36.
• Hadley K, Orlandi RR, Fong KJ. Basic anatomy and physiology of olfaction and taste. Otolaryngol Clin North Am. 2004 Dec;37(6):1115-
26. [PubMed].
• Arvidson K. Location and variation in number of taste buds in human fungiform papillae. Scand J Dent Res. 1979 Dec;87(6):435-42. [PubMed].
• Kakutani Y, Narumi T, Kobayakawa T, Kawai T, Kusakabe Y, Kunieda S, Wada Y. Taste of breath: the temporal order of taste and smell
synchronized with breathing as a determinant for taste and olfactory integration. Sci Rep. 2017 Aug 21;7(1):8922. [PMC free article]
• .NACHMAN M. Taste preferences for sodium salts by adrenalectomized rats. J Comp Physiol Psychol. 1962 Dec;55:1124-9. [PubMed].
• Uneyama H, Kawai M, Sekine-Hayakawa Y, Torii K. Contribution of umami taste substances in human salivation during meal. J Med
Invest. 2009;56 Suppl:197-204. .
• Gilbertson TA. The physiology of vertebrate taste reception. Curr Opin Neurobiol. 1993 Aug;3(4):532-9. [PubMed].
• Ramos Da Conceicao Neta ER, Johanningsmeier SD, McFeeters RF. The chemistry and physiology of sour taste--a review. J Food Sci. 2007
Mar;72(2):R33-.