A detailed presentation on anatomy , embryology , functions , clinical considerations , diseases and examination of tongue
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Anatomy of Tongue
And Its Applied Aspects
Presented by:
Niti Sarawgi
Contents
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
Introduction
Pharyngeal part
Development of tongue
Starts to develop near the end of the fourth week
Epithelium:
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
Posterior most:
from the fourth arch
supplied by vagus 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
Oral Part
•Apex
•Dorsum part
•Ventral part
Ventral surface
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 BlandinNuhn
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 circumvalate and
foliate pappilae
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
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
Pharyngeal or Postsulcal Part
Epiglottis
Lingual
tonsil
Median
epiglotic fold
Lateral
epiglotic fold
valleculae
Palatine tonsil
Muscles of the tongue
Intrinsic muscles
Superior longitudinal
Inferior longitudinal
Transverse
Vertical
Extrinsic muscles
Styloglossus
Hyoglossus
Genioglossus
Palatoglossus
Intrinsic muscles
GenioglossusGenioglossus
Arises from superior genial tubercle above the origin
of geniohyoid
Hyoid bone
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
HyoglossusHyoglossus
•Origin: greater cornu, front of body of hyoid bone
•Insertion: side of the tongue between styloglossus and inferior
longitudinal
ActionsActions
•Depresses the tongue
Chondroglossus
A part of hyoglossus
Separated from it by genioglossus
Origin: medial side and base of lesser cornua
Insertion: intrinsic musculature between hyoglossus and
genioglossus
StyloglossusStyloglossus
•Origin :
styloid process
near its apex
•Insertion :
longitudinal part
into the inferior
longitudinal
muscles
Oblique part into
hyoglossus
•ActionAction
•Draws the
tongue
upwards and
backward
hyoglossushyoglossus
styloglossus
Inferior longitudinal
muscles
Styloid process
PalatoglossusPalatoglossus
Origin: palatine
aponeurosis of soft palate
Insertion: side of the tongue
““more a part of soft palate than more a part of soft palate than
the tonguethe tongue””
ActionAction: 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
Intrinsic muscles
Superior longitudinalSuperior longitudinal
•Origin: submucous fibrous
layer below the dorsum of
the tongue and lingual
septum
•Insertion: extends to the
lingual margin
•ActionAction
•Turns the apex and sides of
the tongue upward to make
the dorsum concave
Inferior longitudinalInferior longitudinal
•Narrow band close to the
inferior surface of the
tongue
•Origin: root of tongue and
body of hyoid bone
•Insertion: apex of tongue
•ActionAction
•Curls the tip inferiorly and
shortens the tongue
TransverseTransverse
•Origin: median fibrous
septum
•Insertion: fibrous tissue at
the margins of tongue
•ActionAction
•Narrows and elongates the
tongue
VerticalVertical
•Origin: dorsum surface of
the borders of the tongue
•Insertion: ventral surface
of the borders of the
tongue
•Action Action
•Flattens and broadens the
tongue
Vascular supply of the tongue
Lingual arteryLingual artery
•A branch of external carotid
artery(after passing deep to the
hyoglossus muscles)
•Divides into :
•Dorsal lingual arteriesDorsal lingual arteries: supply
posterior part
•Deep lingual arteryDeep lingual artery : supplies
the anterior part
•Sublingual arterySublingual artery : supplies the
sublingual gland and floor of
the mouth
•Dorsal lingual vein-Dorsal lingual vein-
drains the dorsum and
sides of the tongue
•Deep lingual veinsDeep lingual veins
(Ranine veins) - drains
the tip of the tongue
and join sublingual sublingual
veinsveins from sublingual
salivary gland
•All these veins
terminate directly or
indirectly into internal internal
jugular veinsjugular veins
Lymphatic drainageLymphatic drainage
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
Innervation of the tongue
Nerve Supply
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)
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)
HISTOLOGY OF TONGUE
Mucous Membrane on Ventral 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.
.
Mucous Membrane On Dorsal Surface
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 2/3
ra
of tongue).
The stratified squamous
epithelium covering the dorsal
surface of the tongue is mostly
keratinized
Papillae of tongue
They are 4 varieties
Filiform
Fungiform
Foliate
Circumvallate
Filiform papillaFiliform papilla
•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 papillaFungiform papilla
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 papillaFoliate papilla
Red leaf-like mucosal
ridges
Bilaterally at the sides
of the tongue near
sulcus terminalis
Bear numerous taste
buds
Circumvallate papillaCircumvallate papilla
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
Special sensory innervation of the tongueSpecial sensory innervation of the tongue
Taste budsTaste buds
•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
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.
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.
Taste discrimination
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
Clinical examination of tongue
•InspectionInspection
•The tongue is examined for:The tongue is examined for:
ColourColour
Swelling
Ulcer
Coating
Size variation
Distribution of filiform and fungiform papilla
Crenations
Fissures
Atrophy or hypertrophy of papilla
Frenal attachment and deviations as patient moves
out the tongue
Palpation
Gently palpate the muscles of the tongue
Clinical considerations
Injury to hypoglossal nerveInjury to hypoglossal nerve
•Trauma like fractured mandible may injure hypoglossal nerve
•Paralysis ,atrophy of one side of tongue
•Tongue deviates to paralyzed side during protrusion due to action
of unaffected genioglossus muscles
• Others
infranuclear lesion (i.e., in motor neuron disease and in
syringobulbia): gradual atrophy and muscular twitchings of
the affected half of the tongue observed
supranuclear lesion (i.e., in pesudobulbar palsy): produce
paralysis without palsy (tongue is stiff, small and moves
sluggishly)
Paralysis of genioglossus muscleParalysis of genioglossus muscle
•Muscle tends to fall backward, obstructing airway
•Total relaxation of genioglossus occur during general
anaesthesia so airway is inserted to prevent tongue
from relapsing
Sublingual absorption of drugsSublingual absorption of drugs
•For quick absorption, pill or spray is put under the
tongue where it dissolves and enter the lingual veins
(nirtroglycerin in angina pectoris)
The presence of rich network of lymphatics and loose areolar
tissue in the substance of tongue is responsible for enormous
swelling of tongue in acute glossitis
The undersurface of the tongue is a good site for observation
of jaundice
Carcinoma of Tongue is quite common. The affected side of
the tongue is removed along with all the deep cervical lymph
nodes
Carcinoma of posterior 1/3 of the tongue is more dangerous
due to bilateral lymphatic spread
In unconscious patients , the tongue may fall and obstruct
the airway.
In grand mal epilepsy, the tongue is commonly bitten by the
front incisors during the attack
Diseases of the tongue
Inherited, congenital, and developmental anomalies
Disorders of the lingual mucosa
Diseases affecting the body of the tongue
Malignant tumors of the tongue
Inherited, congenital, and
developmental anomalies
Variation in morphology
Ankyloglossia
Fissured tongue
Macroglossia
Hypoglossia
Lingual thyroid and thyroglossal duct
•Tongue tie can be classified
as:
•Milder formMilder form: do not influence
jaw development, tooth
position or phonation
•Severe formSevere form: exhibit
Midline mandibular
diastema,
periodontal defects
•Extreme formExtreme form: complete
attachment of tongue to the
floor of the mouth or alveolar
gingiva
Microglossia (hypoglossia)Microglossia (hypoglossia)
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.
MacroglossiaMacroglossia
Fissured, plicated, or scrotal tongueFissured, plicated, or scrotal tongue
Lingual thyroid Lingual thyroid
Proliferation of floor of pharyngeal wall4
th
week
Descends
the neck anterior to trachea and larynx
7
th
week
Pathophysiology of lingual thyroid
Disorders of lingual mucosa
•Geographic tongueGeographic tongue
•Hairy tongueHairy tongue
•Nonkeratotic and keratotic white lesionsNonkeratotic and keratotic white lesions
–Candidiasis
–Leukoplakia, hairy leukoplakia
•Nutritional defficiencies and hematologic Nutritional defficiencies and hematologic
abnormalitiesabnormalities
–Vitamin B12 deficiency
–Iron deficiency anemia
•InfectionsInfections
–Tertiary syphilis
Geographic tongueGeographic tongue::
•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
Hairy tongueHairy tongue
CandidiasisCandidiasis (Moniliasis)
•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
LeukoplakiaLeukoplakia
Pernicious anemiaPernicious anemia
•Most common forms of vitamin
B12 deficiency
Clinical featuresClinical features
•Beefy red tongueBeefy red tongue
•Erythematous areas on tip and
margins
•De-papilation
•Candidal infection
Iron deficiency anemiaIron deficiency anemia
•Most common form of anemia found in 50% females
PlummerVinson syndromePlummerVinson syndrome
Also known as Paterson Kelly
Syndrome
•Clinical featuresClinical features
•Microcytic hypochromic
anemia
•Smooth and sore tongue
•Angular chelitis
•Spoon shaped nails
Disorders of lingual mucosaDisorders of lingual mucosa
Tertiary syphilis and Tertiary syphilis and
interstitial glossitisinterstitial glossitis
•Tongue may be affected by gumma
formation
•Non-ulcerating, irregular
•indurations
•Asymmetric pattern of grooves
•Leukoplakia
Blandin and Nuhn mucocele
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.
Malignant tumors Of Tongue Malignant tumors Of Tongue
Squamous cell carcinoma
Squamous cell carcinoma of the tongueSquamous cell carcinoma of the tongue
Most common intraoral site
60% of lesions arise from the anterior 2/3
rd
of 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.
CONCLUSIO
N
•ReferencesReferences
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.