The tongue, its development and anatomy

Content
• Introduction
• Development of tongue
• Anatomy of tongue
• Parts and surfaces of the tongue
• Muscles of the tongue
• Vascular supply of the tongue
• Lymphatic drainage of the tongue
• Innervation of the tongue
• Examination of the tongue
• Clinical considerations and diseases of the tongue
• Conclusion
• References

• The word ‘tongue’ is derived from the Latin word
‘lingua’ and Greek word ‘glossa’.
• The tongue is a mobile muscular organ in the oral
cavity which bulges upwards from the floor of the
mouth and its posterior part forms the anterior wall
of the oropharynx.
• It is essentially a mass of skeletal muscle covered by
mucous membrane.
INTRODUCTION

• Tongue is separated from teeth by deep alveololingual sulcus.
• The tongue may be affected as a part of oral disease or
as signs of a systemic disease.
INTRODUCTION

⁂ The tongue performs the following functions:
 Taste
 Speech
 Mastication
 Deglutition
 Barrier function
 Jaw development
 Thermal regulation
Function

Function
⁂ The tongue performs the following functions:
 Secretion
 Defence mechanism
 Maintenanceof oral hygiene
 Sucking
 General sensitivity

Development of tongue
• Starts to develop near the end of the fourth week
 Anterior 2/3:
• from 2 lingual swellings and one tuberculum impar, i.e., from first branchial
arch
• supplied by lingual nerve (post-trematic) and chorda tympani (pre-trematic)

 Posterior 1/3:
• from the cranial half of the hypobranchial eminence, i.e., from the third arch
• supplied by glossopharyngeal nerve
☺ Muscles develop from the occipital myotomes which are supplied by
hypoglossal nerve
☺ Connective tissue develops from local mesenchyme

Terminal
sulcus
Hypobrachial
eminence

Parts and surfaces of the tongue
• Apex
• Dorsum
• Ventral

Dorsum of tongue
Posterior 1/3
Anterior 2/3
Terminal sulcus
Epiglottis
Palatine tonsil
Palatopharyngeal arch
Lingual tonsils
Foliate papillae
Palatoglossal arch
Circumvallate papillae
Midline groove of tongue
Filiform papillae
Fungiform papillae
Epiglottis
Palatine tonsil
Palatopharyngeal arch
Lingual tonsils
Foliate papillae
Palatoglossal arch

Ventral part
• The thin strip of tissue that runs vertically from the floor of
the mouth to the undersurface of the tongue is called the
lingual frenulum. It tends to limit the movement of the
tongue.
• On either side of frenulum there is a prominence produced
by deep lingual veins. more laterally there is a fold called
plica fimbriata

Glands of Blandin &Nuhn
• Anterior lingual glands (also called apical glands) are deeply
placed seromucous glands that are located near the tip of the
tongue on each side of the frenulum linguae
• They are found on the under surface of the apex of the tongue, and
are covered by a bundle of muscular fibers derived from the
Styloglossus and Longitudinalis inferior
• They are between 12 to 25 mm. in length, and approximately 8
mm. wide, and each opens by three or four ducts on the under
surface of the tongue's apex

Glands of VonEbner
• They are serous salivary glands
• Located adjacent to the moats surrounding the
circumvallate and foliate papillae
• Von Ebner's glands secrete lingual lipase
• This secretion flushes material from the moat to enable
the taste buds to respond rapidly to changing stimuli
• Von Ebner's glands are innervated by cranial nerve IX,
the glossopharyngeal nerve.

Gland of Weber
• They lie along the lateral border of the tongue
• These glands are pure mucous secreting glands.
• These open into the crypts of the lingual tonsils on the posterior tongue
dorsum.
• Abscess formed due to accumulation of pus and fluids in this gland is called
Peritonsillar Abscess
Weber
von ebner
Blandin-Nuhn

Epiglottis
Lingual
tonsil
Median
epiglotic fold
Lateral
epiglotic fold
valleculae
Palatine
tonsil
Pharyngeal or Postsulcal Part
• Lies behind the palatoglossal arches
• Forms the anterior wall of the oropharynx
• Devoid of papillae
• Underlying lymphoid nodules
embedded in the submucosa collectively
called as lingual tonsils

Muscles of the tongue
II. INTRINSIC MUSCLES
• Superior longitudinal
• Inferior longitudinal
• Transverse
• Vertical
I. EXTRINSIC MUSCLES
• Styloglossus
• Hyoglossus
• Genioglossus
• Palatoglossus

I. Extrinsic muscles

1. Genioglossus
Origin: Arises from superior genial tubercle above the origin of geniohyoid
Insertion: the fibres radiate widely to be inserted into the mucous membrane of
the tongue; the lowest fibres passing down to the hyoid body
Action: . Protrusion
• Bilaterally –Central part depression
• Unilaterally – Diverges to the Opposite side

2. Hyoglossus
Origin: greater cornu, front of body of hyoid bone
Insertion: side of the tongue between styloglossus and inferior longitudinal
Actions
• Depresses the tongue

3. Styloglossus
Origin: styloid process near its apex
Insertion: longitudinal part into the inferior longitudinal muscles Oblique part
into hyoglossus
Actions
• Draws the tongue upwards and backward

4. Palatoglossus
Origin: palatine aponeurosis of soft palate
Insertion: side of the tongue “more a part of soft palate than the tongue”
Actions:
• elevates the posterior part of the tongue
• Bilaterally- approximates the palatoglossal folds to constrict the
isthmus of the fauces

MUSCLES ORIGIN INSERTION ACTION(S)
Genioglossus Upper genial
tubercle of
mandible
Upper fibres: tip
of the tongue
Middle fibres:
dorsum Lower
fibres: hyoid bone
Upper fibres:
retract the tip
Middle fibres:
depress the tongue
Lower fibres: pull the
posterior part
forward (thus
protrusion of the
tongue from the
mouth)
Hyoglossus
Greater cornu, front
of lateral part of
body of hyoid bone
Side of
tongue
Depress the
tongue Retracting
the protruded
tongue
Styloglossus Tip, anterior
surface of styloid
process
Side of
tongue
Pulls the tongue
upwards and
backwards during
swallowing
Palatoglossus Oral surface of
palatine
aponeurosis
Side of tongue
(junction of oral and
pharygeal part)
Pulls up root of
tongue,
approximates
palatoglossal
arches, closes
oropharyngeal
isthmus

II. Intrinsic muscles
transverse
Vertical
longtudinal

1. Superiorlongitudinal
Origin: : submucous fibrous layer below the dorsum of the tongue and lingual
Insertion: extends to the lingual margin
Actions:
• Turns the apex and sides of the tongue upward to make the dorsum
concave

2. Inferior longitudinal
Narrow band close to the inferior surface of the tongue
Origin: root of tongue and body of hyoid bone
Insertion: apex of tongue
Actions:
• Curls the tip inferiorly and shortens the tongue

3. Transverse
Origin: median fibrous septum
Insertion: fibrous tissue at the margins of tongue
Actions:
• Narrows and elongates the tongue

3. Vertical
Origin: dorsum surface of the borders of the tongue
Insertion: ventral surface of the borders of the tongue
Actions:
• Flattens and broadens the tongue

Vascular Supply of the tongue
I. Arterial blood Supply
® Lingual artery
• A branch of external carotid artery(after passing
deep to the hyoglossus muscles)
Divides into :
•Dorsal lingual arteries:
supply posterior part
•Deep lingual artery :
supplies the anterior part
•Sublingual artery :
supplies the sublingual
gland and floor of the
mouth

I. Arterial blood Supply

I. Venous blood Supply
• Dorsal lingual vein
drains the dorsum and sides of the tongue
• Deep lingual veins (Ranine veins)
drains the tip of the tongue and join
sublingual veins from sublingual salivary
gland
All these veins terminate directly or indirectly into
internal jugular vein

I. Venous blood Supply

Lymphatic drainage of the tongue
 Lymph from one side (esp. of the posterior side), may
reach the nodes of the both sides of the neck (in contrast
to the blood supply which remains unilateral)
 Tip - drain to submental nodes or directly to deep
cervical nodes
 Marginal lymphatics from the anterior part tend to
drain to ipsilateral submandibular nodes or directly to
inferior deep cervical nodes

 Central lymphatics - drain to deep cervical nodes of either side
 Posterior part - drains directly and bilaterally to deep cervical nodes
The deep cervical nodes usually involved: jugulodigastric and jugulo-omohyoid
nodes
All lymph from the tongue is believed to eventually drain through the jugulo-
omohyoid node before reaching the thoracic duct or right lymphatic duct
Lymphatic drainage of the tongue

Motor:
 All muscles of the tongue (intrinsic and extrinsic) are supplied by hypoglossal nerve except
palatoglossus which is supplied by pharyngeal plexus
Sensory:
Anterior 2/3 of the tongue:
• general sensation: lingual nerve - branch of the mandibular
nerve (with cell bodies in the trigeminal ganglion)
• taste: chorda tympani (with cell bodies in the geniculate
ganglion of facial nerve)
Innervation of the tongue

• parasympathetic secretomotor fibres to the anterior lingual gland run in the
chorda tympani from the superior salivary nucleus, and relay in the
submandibular genglion
Posterior 1/3 of the tongue:
• innervated by the glossopharyngeal nerve (both general sensation and taste),
with cell bodies in the glossopharyngeal ganglia in the jugular foramen
• posterior most part of the tongue: innervated by the vagus nerve through the
internal laryngeal branch (with cell bodies in the inferior vagal ganglion)
Innervation of the tongue

MucousMembraneonVentral Surface
• It is thin, smooth and loosely attached to the
underlying Connective Tissue
• It is freely mobile and not raised into papillae because
epithelium is closely adherent to underlying muscle
by a thin lamina propria.
• It is covered with non- keratinized stratified squamous
epithelium.

 The dorsal surface Of the tongue is covered
with a mucous membrane, which is firmly
adherent to the underlying C.T.
 It is raised into small projections similar to the
villi, but known as papillae (limited only to
anterior 2/3raof tongue).
 The stratified squamous epithelium covering the
dorsal surface of the tongue is mostly keratinized
MucousMembraneonDorsal Surface

PapilleOfTongue
Filiform
Fungiform
Foliate
Circumvallate
Filiform papillae
Fungiform papillae
Foliate papillae

Filiform
• Minute, conical, cylindrical projections which
cover most of the presulcul dorsal area.
• Increase the friction between the tongue and food
• They bear many secondary papillae which are
more pointed than those of vallate and fungiform
papillae and covered with keratin

Fungiform
• Located mainly on the lingual margin
• Differ from filiform because are larger, rounded
and deep red in colour
• Bears one or more taste buds on its apical surface
These are mushroom shaped, more numerous
near tip & margins of tongue but some of them
scattered over the dorsum

Foliate
• Red leaf-like mucosal ridges
• Bilaterally at the sides of the tongue near sulcus
terminalis Bear numerous taste buds

circumvallate
• Large cylindrical structures
• 8 to 12 in number
• Form a ‘V’ shaped row in front of sulcus terminalis
on the dorsal surface of the tongue
• The entire structure is covered with squamous
epithelium, in both sulcal walls & taste buds
around

• Present in relation to cirumvallate papilla,
fungiform papillae and foliate papilla
• Also present on the soft palate, the epiglottis, the
palatoglossal arches, and the posterior wall of
the oropharynx
TasteBuds

Neuroepithelial taste cells or gustatory cells in taste buds
They are modified columnar elongated cells which act as
receptors. They have darkly-stained' elongated central nuclei.
The superficial part of these cells is provided with short hairs
(hairlets or microvilli). These hairlets project into the taste
pore. The base of the taste cells is surrounded by sensory
nerve fibres, carry the impulses of taste sensation to the
brain.
TasteBuds

 Supporting cells in taste buds They are elongated columnar cells with dark
cytoplasm but lightly-stained nuclei.
• They form the outer wall of the taste bud. They have
• long microvilli that extend from their surfaces into the taste pore.
 Basal cells are present at the base of the taste bud.
• They act as stem cells for renewal of taste cells and supporting cells.
TasteBuds

Gustatory receptors detect four main types of taste
sensation
 Sweet: tip
 Sour: middle
 Salty: anterolateral
 Bitter: base
However recent evidence indicates that all areas of
tongue are responsive to all taste stimuli
TasteDiscrimination

Inherited, congenital, and
developmental anomalies
 VARIATIONS IN MORPHOLOGY
 ANKYLOGLOSSIA
 FISSURED TONGUE
 MACROGLOSSIA
 HYPOGLOSSIA
 LINGUAL THYROID AND THYROGLOSSAL DUCT

PartialAnkyloglossia(Tonguetie)

 Milder form:
do not influence jaw
development, tooth
position or phonation
 Severe form:
exhibit Midline mandibular
diastema, periodontal
defects
 Extreme form:
Complete attachment of
tongue to the floor of the
mouth or alveolar gingiva
PartialAnkyloglossia(Tonguetie)

 Uncommon developmental condition of unknown origin characterized by
abnormally small tongue
 Entire tongue may be missing (aglossia)
 length of the mandibular arch will be smaller due to the smaller size of the
tongue.
Microglossia(Hypoglossia)

Fissured,plicated,ORscrotaltongue

Proliferation of floor of pharyngeal wall 4th week
Descends
the neck anterior to trachea and larynx 7th week
Pathophysiology of lingual thyroid

 Geographic tongue
 Hairy tongue
 Nonkeratotic and keratotic white lesions
 Candidiasis
Leukoplakia, hairy leukoplakia
Nutritional defficiencies and hematologic abnormalities
• Vitamin B12 deficiency
• Iron deficiency anemia
 Infections
• Tertiary syphilis
DisordersOfLingualMucosa

• Psoriasiform mucositis of the dorsum of the tongue
• Prevalence is 1% to 2%
• Irregular reddish areas of depapillation
• thinning of the dorsal tongue epithelium usually
surrounded by a narrow zone of regenerating papillae
• whiter than the surrounding tongue surface
GeographicTongue

 Most common intraoral oppertunistic fungal
infection
 Causative agent: Candida albicans
 Factors determining the clinical evidence of
candidiasis:
• Immune status of the host
• Oral mucosal enviroment
• Strains of Candida
Candidiasis(Moniliasis)

• Most common forms of vitamin B12 deficiency
• Clinical features
• Beefy red tongue
• Erythematous areas on tip and margins
• De-papilation
• Candidal infection
Perniciousanemia

 Most common form of anemia found in 50% females
 Clinical features
• Pallor of Oral mucosa
• Depapillation of tongue
• Angular chelitis
 Other Symptoms
• Fatigue
• Easy tiring
• Palpitations
• Lightheadedness
• Lack of energy
IronDeficiencyanemia

 Also known as PatersonKelly Syndrome
 Clinical features
• Microcytic hypochromic anemia
• Smooth and sore tongue
• Angular chelitis
• Spoon shaped nails
PlummerVinsonSyndrome

• Tongue may be affected by gumma formation
• Non-ulcerating, irregular indurations
• Asymmetric pattern of grooves
• Leukoplakia
TertiarySyphilisandinterstitialglossitis

The Blandin and Nuhn mucocele occurs exclusively on the
anterior ventral surface of the tongue at the midline.
 Although the lesions may have clinical features similar to
those of the mucocele, which is found elsewhere they tend
to be more polypoid with a pedunculated base
Because of repeated trauma against the lower teeth, the
surface may be red and granular or white and keratotic.
BlandinandNuhnmucocele

 Most common intraoral site
 60% of lesions arise from the anterior 2/3rdof the tongue. The affected side of the tongue is
removed surgically.
 All the deep cervical lymph nodes are also removed, i.e. block dissection of neck.
 Unilateral block dissection of the neck should be efficacious for early carcinoma of the lateral border
of the tongue but because of the bilateral lymphatic drainage bilateral dissection should be
performed if the tip of the tongue, the frenulum ,or the dorsum of the tongue is involved.
SquamousCellCarcinomaOfTheTongue

√ B.D Chaurasia(2006) Human Anatomy,Regional and Applied,Dissection.
√ Henry Gray(2004),Gray's Anatomy .
√ Neelima Anil Malik, Textbook of Oral and Maxillofacial Surgery.
√ Frank H.Netter,MD. Atlas of human anatomy.
√ William Henry Hollinshead. Anatomy for Surgeons: The head and neck
√ T.W. Sadler ,Langman’s Medical Embryology
√ Internet source.
References

The tongue, its development and anatomy

The tongue, its development and anatomy

Empfohlen

Empfohlen

Weitere ähnliche Inhalte

Was ist angesagt?

Was ist angesagt? (20)

Ähnlich wie The tongue, its development and anatomy

Ähnlich wie The tongue, its development and anatomy (20)

Kürzlich hochgeladen

Kürzlich hochgeladen (20)

The tongue, its development and anatomy