SENSORY ORGANS

1. Presented by:- Lingaraj .V. Anawal
MPharm – 1st SEM
Department of Pharmacology
H S K College of Pharmacy Bagalkot
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2. These are the organs of the
body which responds to external stimuli
by conveying the impluses to the
sensory nervous system.
 Eyes (sense of sight)
 Nose (sense of smell)
 Ears (sense of hearing)
 Skin (sense of touch)
 Tongue (sense of tasting)
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3. TONGUE
 Voluntary muscular structure.
 Mass of striated muscle covered with mucous
membrane(pink tissue)
 Length:- 3inch
 Location:- floor of the mouth.
 Shape:- triangular
 Attachment:- with mandible and hyoid bone.
 It has apex, body, and root.
 The sensation of taste is called Gustation.
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4.  PARTS OF TONGUE
 ROOT:-
 Located between the hyoid bone and mandible.
 Dorsal portion sits in the oropharynx.
 Attaches the tongue to roof of the mouth
 BODY:-
 Makes up the anterior
2/3rd of the tongue.
 Rough surface due to
the lingual papillae.
 Surrounded by anterior and lateral teeth.
 Mobile portion of the tongue.
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5.  APEX
 Also known as the tip, is the anterior 1/3rd of the
anterior tongue surface.
 Rests against the incisor teeth.
 Highly mobile.
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6.  TONGUE
 The receptors for taste,
called taste buds, are
situated chiefly in the
tongue, they are also
located in the roof of the
mouth and near the
pharynx. They are able to
detect four basic tastes:
sweet, salty, bitter, and sour.
The tongue also detect a
sensation called ‘umami’
from the taste receptors
sensitive to amino acids.
 Umami is from japanese
word which means
‘pleasant savory taste’.
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7.  Human tongue has ‘Gluatmate receptors’ which is
the source of ‘umami flavour’
 The taste buds which are close to the tip of the
tongue are sensitive to sweet to bitter tastes.
 The taste buds on the top and on the sides are
sensitive to salty and sour tastes.
 At the base of each taste bud there is a nerve that
sends the sensation to the brain.
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8. Chemical Taste Nerves
substance receptors
(food)
Taste is Nerves Brain
Identified (interprets the message)
(dissolves in
saliva)
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9.  SURFACE
Two surfaces
:- Superior or dorsal (top) surface
:- Inferior or ventral (underside)surface
 Superior(dorsal)surface is divided into 3
parts
i. Anterior 2/3 part called as oral part
ii. Posterior 1/3 part called as pharyngeal part
iii. Base of the tongue(root)
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10. SUPERIOR (DORSAL) SURFACE
 Anterior 2/3 part called as oral part
 Made up of the apex at the tip & body.
 It comprises of a median furrow.
 Rough surface due to presence of papillae.
 It is surrounded by anterior and lateral teeth.
 Tongue is mobile part.
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11.  Posterior 1/3part called as pharyngeal part
 Made up of entirely of the root.
 Lies behind the sulcus terminalis.
 No papillae, shows nodular surface, presence
of lymphatic nodules and lingual tonsiles
 Contributes to the anterior wall of oropharynx
 Base of tongue
 The base of the tongue is far back and is bottom
of tongue.
 Contributes to the front wall of pharynx.
 Movement can affect the diameter of pharynx.
 [ when it push forward, thereby expanding the
pharynx ]
 [ when it pull backwards, thereby constricting the
pharynx ]
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12. INFERIOR (VENTRAL) SURFACE
 Made up of the body and apex.
 Covered by smooth mucous membrane.
 In the midline, a mucosal fold
called frenulum connects
the tongue with the floor
of the mouth.
 Lateral to frenulum,
deep lingual vein can be
seen through the mucosa.
 Lateral to the vein, mucosal fold called as plica
fimbriata is present.
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13. TASTE BUDS
 Taste buds are sensory organs that are found
on your tongue and allow you to experience
tastes.
LOCATION OF TASTE BUDS
 The buds contain sensory receptors found in the
papillae of tongue and widely distributed in the
epithelium of tongue, soft palate, pharynx and
epiglottis.
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14. Structure of taste buds
 Oval barrel in shape 70µm-50µm.
 Life span – 10 days
 Having a opening called taste pores.
 Composed of 5 -15 gustotary receptors cell,
40 supporting cells or subtentacular cell and
15-20 transitional cells.
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15. Electronic microscopy of structure of
taste buds.
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16. PAPILLA
 Papilla it is a small rounded protuberance on a
part or organ of the body.
 The papilla is located as a small structure around
there is a taste receptors are situated.
 Superior surface of tongue is covered by
numerous papillae.
 These papillae contain taste buds.(10,000)
 Types of papillae:-
 Fungiform papillae.
 Filiform papillae.
 Foliate papillae.
 Vallate/circumvallate
papillae.
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17. 17

18.  Fungiform papilae
 Shape:-slightly mushroom-shaped if looked at in
longitudinal section.
 Taste buds on their surface.
 Location:-apex of the tongue as well as the
margins(sides)
 Larger than filiform papillae.
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19.  Filiform papillae
 Shape:- thin, long papillae having pointed ends.
 V shaped cones
 Only this papillae having no taste buds.
 Number:- numerous
 These papillae are mechanical and not involved in
gustation.
 Location :-present at pre-sulcal area of the tongue
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20.  Foliate pappilae
 Shape:-short vertical folds.
 Location:-present lateral to terminal sulcus and
at margins.
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21.  Vallate / Circumvallate papillae.
 It is largest amoung papillae.
 Shape:- Blunt ended cylindrical
 Number:- 8 to12
 Location:- infront of sulcus terminalis
 Arrangement :-occur in v shape line
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22. PHYSIOLOGY OF GUSTATION/TASTE
Food(chemical)+saliva
contact
Plasma membrane
(gustatory hairs)
enters
Gustatory receptor cell
receptor potential
Exocytosis of
Synaptic vesicles
release of neurotransmitter molecules
(chemical)
Nerve impluses to Salty
sensory neurons Sour 22

23. Sweet, Bitter, umami (food)
binds to receptors on the
plasama membrane
G proteins coupled - Receptors
activate of chemicals
(secondary messengers)
Gustatory receptor cell
receptor
potential
Exocytosis of synaptic vesicles
release of neurotransmitter
molecules (chemical)
Nerve impluses to sensory neurons
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24. DISORDER OF TONGUE
 Microglossia
 Macroglossia
 Ankylglossia
 Cleft tongue
 Fissured tongue
 Median rhomboid glossitis
 Begin migratory glossitis
 Hairy tongue
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25. MICROGOSSIA
 This is a condition where the size of the tongue
is abnormally small.
 Some case also give a complete absence of
tongue have been reported(it is in rare condition)
 A tiny tongue will pose
many difficulties relate
to speech and
swallowing.
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26. MACROGLOSSIA
 This is much more comman condition than
microglossia, where the tongue is highly
enlarged.
 Causes the functional
difficulties in speaking,
eating, swallowing, &
sleeping.
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27. ANKYLOGLOSSIA / ‘TONGUE TIE’
 It is condition in which result in the fusion of
lingual frenum to the floor the mouth.
 Complete fusion is rarely occurs.
 Partial ankyloglossia or ‘tongue-tie’ is more
comman condition.
 This lead to speech
problems such as
lisping and stuttering.
 The treatment is to
surgically sever the connection
between the frenulum and the floor of the mouth.27

28. CLEFT TONGUE/BIFIED TONGUE
 Cleft tongue is condition where the tongue has a
cleft running right across it horizontally or
vertically.
 Many cases have reported has vertically cleft.
 But complete clefting is extremely rare.
 Cleft tongue is little importance other than
causing difficulty in eating as food gets stuck in
the cleft.
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29. FISSURED TONGUE
 This condition is also referred to as scortal
tongue since the tongue often resembles the
scortum in this state.
 Presence of grooves on the tongue from which
smaller grooves are radiate all over the surface
of the tongue.
 This condition is painless and the problem is
with that suck of food in the grooves.
 These are cleaned by toothbrush.
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30. FISSURED TONGUE
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31. MEDIAN RHOMBOID GLOSSITIS
 It is a the smooth, red, flat or raised nodular
area on the top Part of the middle of the tongue.
 The affected area of tongue is missing of
papilla.
 Median rhomboid glossitis refers to:-
 Median =affected area located near the centre
of tongue
 Rhomboid =shape of affected area
 Glossitis =inflammation
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32. MEDIAN RHOMBOID GLOSSITIS
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33. BENGIN MIGRATORY GLOSSITIS
 This is condition is called a geographic tongue
due to the behaviour of the lesions, which tend
to migrate from one area of the tongue to
another.
 Exact cause is still not known.
 Female are twice as affected as males,
 These are yellowish-white or deep red in colour
depending on the papillae that are affected.
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34. HAIRY TONGUE
 This is a condition charaterized by the
hypertropy of the filiform papillae of the tongue.
 If the papillae become stained with tobacco,
they appear black in colour and look like hair on
the tongue.
 The tounge appers yellowish-white if foodstuff is
trapped within the papillae.
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35. FUNCTION OF TONGUE
 Mastication (act of chewing)
 Deglutition (act of swallowing)
 Taste (general sensation)
 Speech (essential)
 Secretion (mucus & fluids that keep mouth
moist)
 Bolus (mixed food with saliva)
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36. INTRESTING FACTS
 Women have shorter tongue than men.
 Tongue heals faster than any part of
the body.
 If your tongue is pink in colour then it
is germ free. but it is white there is thin
film of bacteria on it.
 The longest human tongue to be ever
recorded was 3.97(10.1 cm) inches from
back to tip.
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37. REFERENCE:-
 HUMAN ANATOMY AND PHYSIOLOGY- l =
S.S. RANDHAWA & ATUL KABRA.
 BASICS OF HUMAN ANATOMY AND
PHYSIOLOGY = Dr.Ramesh .K. Goyal
B.S. SHAH PRAKASHAN.
 HUMAN ANATOMY AND PHYSIOLOGY =
S.Chaudhary & A. Chaudhary.
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38. THANK YOU
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