Tongue is a muscular structure that has the organs of taste reception. The organs for sense of taste are the taste buds. Tongue is located inside the mouth and is an important muscle. It does not have any bones. It is reddish-pink in color. The main function of tongue is taste, help in chewing food, in swallowing food and speech.

1. The
Tongue

2. Tongue is a muscular structure that
has the organs of taste reception.
The organs for sense of taste are
the taste buds. Tongue is located
inside the mouth and is an important
muscle. It does not have any bones.
It is reddish-pink in color. The main
function of tongue is taste, help in
chewing food, in swallowing food and
speech.

3. Human Tongue

4. Papillae
Papillae contains taste bud (chemo-
receptors), which helps us identify
between different tastes of food.
When we chew food, a portion of it
dissolves in the saliva. This dissolved
part of food comes in contact with the
taste buds and generates nerve impulses.
These nerve fibres are known as
microvilli. These nerve fibres carry
messages to the taste center in the
brain. Then brain perceives the taste.

5. Four Types Of Papillae
-Foliate, Vallate and
Fungiform have
taste buds which
helps in identifying
the taste
-Filiform helps in
holding the food ( to
grip the food in
place)

6. Tonsils Adenoids
The main function of They help in
tonsils is to serve as fighting infections
the first line of
defense in the immune
system.

7. Types of Tonsils
1. The palatine tonsils or simply referred to as
'the tonsil'- inbetween the anterior &
posterior pillars of oropharynx
2. The Nasopharyngeal tonsils or the
adenoids- in the nasopharynx
3. The tubal tonsils- near opening of
eustachian tubes.
4. The Lingual tonsils- in the base of the
tongue.
5. Tonsillar patches in posterior pharyngeal
wall.

8. Frenulum linguae: It secures or
holds the tongue in place inside the
mouth.
Very small fibre-like or hair-like
projections are present on the upper
side of the tongue which connect with
nerve fibres at the lower end of the
tongue which lead to the brain.

9. Taste Buds
-Are structures located on the surface
of the tongue. They are embedded in
the mucosa of the papillae of the
tongue. The papillae are projections on
the upper surface of the tongue.
-Taste buds contain the receptors for
taste

10. Structure of Taste Buds

11. There are about 3000 taste buds on the
tongue of an adult person. There are
four main tastes - sweet, salty, sour
and bitter. These four main tastes are
felt by different portion of the tongue.
The tip of our tongue senses salt and
sweet. The taste buds at the sides
detect sour taste. The rear portion of
the tongue detect bitter taste.

12. Four Main Taste

13. Taste receptor cells or
gustatory receptors
They are spindle-shaped cells that are
neurosensory. They have hairs on their
free ends and on the other end, they
have nerve fibres. They number 5-15
in each taste bud

14. Supporting cells
They are columnar cells, numbering
about 40 found between the taste
receptor cells, supporting them.

15. Human Tongue
Diseases

16. Oral Candidiasis
Candidiasis is a fungal infection, which is
mostly caused a yeast called Candida
albicans. Other less common causative
agents are Candida glabrata and
Candida tropicalis. When it occurs on
the mucous membrane of the mouth, it
is known as oral candidiasis.The
identifying symptoms are appearance
of thick white or cream-colored
deposits on the surface of tongue.

17. The infected tongue may appear red and
a bit raised from the normal level.
Oral candidiasis causes a burning
sensation and a lot of discomfort. It is
treated with antifungal drugs. The
patient is asked to use this oral
suspension to wash around the mouth
and swallow. In some severe cases, the
medicine may be administered
intravenously on the tongue.

18. Leukoplakia
Leukoplakia is a disease the involves the
formation of a white spot or patch on the
mucous membrane in the mouth. The common
mouth parts that develop leukoplakia are
tongue, gums, etc. If not treated on time,
leukoplakia may lead to cancer. The
leukoplakia patches on tongue cannot be
easily scraped off. The common causes of it
are smoking and chewing tobacco. In
majority of the cases, this tongue disease is
harmless. But seeking dental assistance is
necessary to prevent cancer.

19. Keratosis Pharyngis
It occurs when the protein of the hair
or nails, called keratin, grows at the
pharynx. This is a tongue disease
which belongs to a group of those
disease for which there is no
treatment known till date. The
identifying symptoms are pain at the
back of the throat and difficulty in
swallowing.

20. Quiz time

21. 1.) A muscular structure that has the
organs of taste reception.
2.) Its contains taste buds which helps us
identify between different tastes of
food.
3-6.) Give the four types of Papillae
7.) Serve as the first line of defense in the
immune system.
8.) Contain the receptors for taste
9.) It secures or holds the tongue in place
inside the mouth.
10.) They are spindle-shaped cells that are
neurosensory.