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According to a document from 2019, the tongue is described as a muscular organ in the floor of the mouth, involved in taste, speech, chewing, swallowing, and oral cleansing.
It contains skeletal (voluntary) muscle, though its automatic movements may feel involuntary in daily usage.
The sagittal section shows the fan-shaped genioglossus muscle.
Dissection requires cutting buccinator, superior constrictor, and the pterygomandibular raphe to expose the lateral tongue.
The tongue consists of root, body, and tip.
Attached superiorly to styloid process and soft palate, and inferiorly to mandible and hyoid bone, making the tongue impossible to swallow accidentally.
Free anterior end, resting behind the upper incisors.
Includes dorsum and inferior surface:
Dorsum is convex; divided into:
Oral (anterior 2/3): rough, with papillae
Pharyngeal (posterior 1/3): smooth, contains lingual tonsil
Posteriormost part attached to epiglottis through median and lateral glossoepiglottic folds, spaces forming valleculae.
Based on the document:
Glossitis occurs with generalized stomatitis; filiform papillae atrophy in anaemia.
Tongue may swell enormously due to loose areolar tissue and rich lymphatics.
Undersurface is helpful for observing jaundice.
In unconscious patients, tongue may fall back and obstruct airway; prevented by positioning or pulling tongue forward.
Lingual tonsil forms part of Waldeyer's ring.
According to the document:
8–12 in number, 1–2 mm diameter
Located just anterior to sulcus terminalis
Surrounded by circular sulcus
Contain taste buds
Present near tip and margins, scattered on dorsum
Bright red, mushroom-shaped
Most numerous, smallest
Cover presulcal region; keratinized, giving velvety appearance
Apex may form filamentous processes
Leaf-shaped
Present at lateral borders anterior to vallate papillae
The tongue is divided into two halves by a midline fibrous septum; each half contains 4 intrinsic and 4 extrinsic muscles.
Modify the shape of tongue:
Superior longitudinal
Elevates tip & sides; shortens tongue
Inferior longitudinal
Curls tip down; shortens tongue
Transverse
Narrows and thickens tongue
Vertical
Broadens the tongue
Modify position of tongue:
Genioglossus
Hyoglossus
Styloglossus
Palatoglossus
According to a document from 2019, the hypoglossal nerve is described as the motor nerve of the tongue and supplies all intrinsic and 3 extrinsic muscles (except palatoglossus).
Leaves skull through hypoglossal canal.
Lies between internal jugular vein and internal carotid artery, anterior to vagus.
Curves forward crossing internal & external carotid arteries.
Crosses loop of lingual artery, then lies on hyoglossus and enters the tongue.
All intrinsic muscles.
Extrinsic: Genioglossus, Hyoglossus, Styloglossus.
Exception: Palatoglossus (via pharyngeal plexus).
The same document explains:
Common; requires removal of tongue and block dissection of cervical nodes due to lymphatic spread.
Drugs like sorbitrate act rapidly because of rich blood supply and bypassing of portal circulation.
Paralysis causes tongue to fall back, occluding the airway.
Used to test XII nerve: deviation towards paralyzed side on protrusion.
According to the 2019 document:
Bulk formed of striated skeletal muscle bundles.
Stratified squamous epithelium; thin on oral dorsum, elevated into papillae.
Posterior third contains dense lymphoid follicles.
Inferior surface: thin, smooth epithelium.
Both mucous & serous glands beneath mucosa.
Numerous around vallate papillae, foliate papillae, posterior 1/3; absent in mid-dorsal oral tongue.
Composed of supporting cells and gustatory cells.
According to the 2019 document (Fig. 17.11):
Anterior 2/3
From two lingual swellings of first arch;
Sensory supply: lingual nerve (general), chorda tympani (taste).
Posterior 1/3
From hypobranchial eminence of 3rd arch;
Supplied by glossopharyngeal nerve.
Posteriormost part
From 4th arch;
Supplied by vagus (internal laryngeal).
From occipital myotomes, explaining hypoglossal supply.
According to the 2019 document:
Except vallate papillae
Via chorda tympani → geniculate ganglion → tractus solitarius (medulla).
Via glossopharyngeal nerve → inferior ganglion → tractus solitarius.
Via vagus nerve → inferior ganglion → tractus solitarius.
From tractus solitarius → solitario-thalamic tract
Joins trigeminal lemniscus
Projects to VPM nucleus of thalamus (opposite side)
Then to primary gustatory cortex (inferior postcentral gyrus).
According to the 2019 document:
Taste loss can occur with lesions of facial, glossopharyngeal, or vagus pathways (implied through pathway description).
Taste buds absent in mid-dorsal anterior tongue explains sparing of taste in that region during disease.
All four intrinsic muscles of the tongue are supplied by the hypoglossal nerve (XII).
Of the four extrinsic muscles, three (genioglossus, hyoglossus, styloglossus) are supplied by the hypoglossal nerve; palatoglossus is supplied by the pharyngeal plexus.
The lingual artery is tortuous because it moves with the pharynx during swallowing.
The tongue maintains its position through the attachments of four pairs of extrinsic muscles.
Circumvallate papillae are few (10–12) but contain the maximum number of taste buds; their taste sensation is carried by the glossopharyngeal nerve (IX).
Nerve supply follows embryological development:
Anterior two-thirds → First pharyngeal arch, supplied by the lingual nerve (general sensation) and chorda tympani (taste).
Posterior one-third → Third arch, supplied by the glossopharyngeal nerve.
Posteriormost part → Fourth arch, supplied by the internal laryngeal branch of the vagus nerve.
Sublingual drug administration works rapidly because venous drainage bypasses the portal circulation.
Genioglossus is considered the life-saving muscle, as its action of protruding the tongue prevents airway obstruction.
A patient is diagnosed with right-sided medial medullary syndrome.
What happens to the tongue?
Which nuclear column does the hypoglossal nerve belong to?
What are the muscles of the tongue?
In medial medullary syndrome, the lesion involves the hypoglossal nerve, pyramidal tract, and medial lemniscus due to obstruction of the anterior spinal artery.
Tongue deviation:
The tongue deviates to the right side (side of the lesion) on protrusion because of paralysis of ipsilateral tongue muscles.
Nuclear column:
The hypoglossal nerve belongs to the General Somatic Efferent (GSE) column.
Muscles of the tongue:
Intrinsic muscles:
Superior longitudinal
Inferior longitudinal
Transverse
Vertical
Extrinsic muscles:
Genioglossus
Hyoglossus
Styloglossus
Palatoglossus
A patient undergoes surgery for a carotid endarterectomy. After the procedure, he develops slurred speech and difficulty protruding the tongue.
The hypoglossal nerve may have been injured during dissection around the carotid arteries.
On protrusion, the tongue deviates toward the injured side.
Loss of genioglossus action can allow the tongue to fall backward, risking airway obstruction.
A patient undergoing third molar (wisdom tooth) extraction experiences loss of general sensation and taste in the anterior two-thirds of the tongue.
The lingual nerve (general sensation) and fibres of chorda tympani (taste, parasympathetic) are vulnerable during mandibular molar surgery.
Injury leads to:
Loss of touch, pain, temperature
Loss of taste
Reduced salivary secretion from submandibular and sublingual glands
A patient with a tumour in the posterior tongue presents with loss of taste and sensation in the posterior one-third.
The glossopharyngeal nerve supplies both taste and sensation to this region.
Loss causes impaired gag reflex (afferent limb) and difficulty swallowing.
A chronic smoker presents with a non-healing ulcer on the lateral border of the tongue.
Lateral tongue drains to deep cervical lymph nodes; hence early metastasis is common.
This is why cancers on the posterior or lateral tongue behave more aggressively than those near the tip.
A child presents with an abnormally large tongue causing speech difficulty and airway obstruction.
Conditions like hypothyroidism or lymphangioma cause massive enlargement.
The clinical danger arises because the tongue’s loose areolar tissue allows rapid swelling and obstructs the airway.
A patient with chronic otitis media reports loss of taste in anterior 2/3 of tongue.
The chorda tympani passes through the middle ear and is vulnerable during infection.
Damage causes loss of taste, though general sensation remains intact (lingual nerve is normal).
A patient with dental infection develops floor-of-mouth swelling, fever, and difficulty breathing.
Infection spreads to the sublingual and submandibular spaces.
Tongue is pushed upward and backward, risking fatal airway obstruction.
Emergency airway management is crucial.
A patient cannot curl or shape the tongue properly to whistle.
Damage to intrinsic muscles of the tongue affects tongue shape control.
Hypoglossal nerve lesions impair both intrinsic and extrinsic functions.
A patient loses the gag reflex on the right side.
Afferent limb: Glossopharyngeal nerve (posterior tongue + pharynx)
Efferent limb: Vagus nerve
Loss of sensation on the posterior tongue is an important clue.
A young woman complains of burning sensation, smooth tongue, and taste disturbances.
Likely due to atrophy of filiform papillae in iron-deficiency anaemia.
The tongue appears glossy and smooth
Anterior two-thirds (oral part)
Posterior one-third (pharyngeal part)
Small posteriormost part near epiglottis
Oral (papillary) part
Pharyngeal (lymphoid) part
Separated by sulcus terminalis
There are four types of papillae:
Vallate
Fungiform
Filiform
Foliate
Vallate papillae contain the maximum taste buds.
Genioglossus — Hypoglossal nerve
Hyoglossus — Hypoglossal nerve
Styloglossus — Hypoglossal nerve
Palatoglossus — Pharyngeal plexus
Superior longitudinal
Inferior longitudinal
Transverse
Vertical
All supplied by hypoglossal nerve.
Deep cervical lymph nodes (especially jugulodigastric & jugulo-omohyoid)
Protrudes the tongue forward
Prevents airway obstruction
Also called the "life-saving muscle"
Anterior two-thirds from first pharyngeal arch
Posterior one-third from third arch
Posteriormost part from fourth arch
Anterior 2/3:
General: Lingual nerve
Taste: Chorda tympani
Posterior 1/3:
Both general & taste: Glossopharyngeal nerve
Posteriormost part + epiglottis:
Taste: Internal laryngeal branch of vagus
Deviates to the right side
Because the right genioglossus is paralysed
Circumvallate → Glossopharyngeal nerve
→ Inferior ganglion
→ Tractus solitarius
→ Solitario-thalamic tract
→ VPM nucleus of thalamus
→ Lower part of postcentral gyrus
Sorbitrate
Rapid absorption due to rich vascularity and bypassing portal circulation
Colour helps detect diseases such as jaundice
Roughness depends on papillae; loss (e.g., iron deficiency) makes tongue smooth
a. Lingual nerve
b. Chorda tympani
c. Glossopharyngeal nerve
d. Internal laryngeal nerve
Correct answer: c. Glossopharyngeal nerve
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a. Vagus nerve
b. Glossopharyngeal nerve
c. Hypoglossal nerve
d. Facial nerve
Correct answer: c. Hypoglossal nerve
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a. Hypoglossal nerve
b. Facial nerve
c. Pharyngeal plexus
d. Glossopharyngeal nerve
Correct answer: c. Pharyngeal plexus
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a. Second
b. First
c. Third
d. Fourth
Correct answer: b. First
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a. Glossopharyngeal nerve
b. Hypoglossal nerve
c. Lingual nerve
d. Internal laryngeal nerve
Correct answer: b. Hypoglossal nerve
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a. Filiform
b. Fungiform
c. Foliate
d. Vallate
Correct answer: d. Vallate
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a. Jugulo-omohyoid node
b. Jugulodigastric node
c. Submental node
d. Parotid node
Correct answer: c. Submental node
(From anatomical correlation, consistent with text where tongue lymphatics are discussed.)
a. It has slow absorption
b. It is digested by salivary enzymes
c. It bypasses the portal circulation
d. It requires lymphatic transport
Correct answer: c. It bypasses the portal circulation
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a. Lingual nerve
b. Chorda tympani
c. Glossopharyngeal nerve
d. Vagus nerve
Correct answer: d. Vagus nerve
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a. Styloglossus
b. Hyoglossus
c. Genioglossus
d. Palatoglossus
Correct answer: c. Genioglossus
a. Chorda tympani
b. Glossopharyngeal nerve
c. Lingual nerve
d. Vagus nerve
Correct answer: c. Lingual nerve
a. Lingual nerve → Geniculate ganglion
b. Lingual nerve → Trigeminal ganglion
c. Chorda tympani → Otic ganglion
d. Chorda tympani → Inferior ganglion of IX
Correct answer: a. Lingual nerve → Geniculate ganglion (via chorda tympani)
a. Facial
b. Glossopharyngeal
c. Trigeminal
d. Vagus
Correct answer: d. Vagus (internal laryngeal branch)
a. Fungiform
b. Vallate
c. Filiform
d. Foliate
Correct answer: c. Filiform
a. Lingual nerve before joining chorda tympani
b. Chorda tympani
c. Glossopharyngeal nerve
d. Vagus nerve
Correct answer: b. Chorda tympani
a. Styloglossus
b. Palatoglossus
c. Genioglossus
d. Hyoglossus
Correct answer: c. Genioglossus
a. Lateral lingual swellings
b. Hypobranchial eminence
c. Tuberculum impar
d. Epiglottic swelling
Correct answer: b. Hypobranchial eminence
a. Motor nucleus of V
b. Nucleus ambiguus
c. Nucleus tractus solitarius
d. Chief sensory nucleus
Correct answer: c. Nucleus tractus solitarius
a. Left
b. Right
c. Both sides
d. Cannot determine
Correct answer: a. Left
a. Hyoglossus
b. Genioglossus
c. Styloglossus
d. Palatoglossus
Correct answer: c. Styloglossus
a. Palatoglossal arch
b. Palatopharyngeal arch
c. Faucial isthmus
d. Sulcus terminalis
Correct answer: a. Palatoglossal arch
a. Fungiform
b. Filiform
c. Foliate
d. Vallate
Correct answer: c. Foliate
a. Facial nerve
b. Glossopharyngeal nerve
c. Trigeminal nerve
d. Vagus nerve
Correct answer: b. Glossopharyngeal nerve
a. Anterior two-thirds
b. Posterior one-third
c. Tip of tongue
d. Inferior surface
Correct answer: b. Posterior one-third
a. Lingual artery is straight and fixed
b. Lingual artery is tortuous and moves during swallowing
c. Venous drainage is mainly to subclavian vein
d. Arterial supply is via facial artery alone
Correct answer: b. Lingual artery is tortuous and moves with pharyngeal movements
Tip
Body (anterior two-thirds)
Posterior one-third
Posteriormost part near epiglottis
A V-shaped groove separating anterior two-thirds from posterior one-third.
Vallate
Fungiform
Filiform
Foliate
Vallate papillae
Filiform papillae
Lingual nerve
Chorda tympani (via lingual nerve)
Glossopharyngeal nerve
Internal laryngeal branch of vagus
Superior longitudinal
Inferior longitudinal
Transverse
Vertical
Genioglossus
Hyoglossus
Styloglossus
Palatoglossus
Pharyngeal plexus (not hypoglossal)
Tongue deviates toward the affected side on protrusion.
Genioglossus — called the life-saving muscle.
Lymphoid follicles in the posterior one-third of the tongue.
Rich vascularity
Direct entry into systemic circulation
Bypasses portal system
Styloglossus
Hyoglossus
Genioglossus
Presence of loose areolar tissue
Rich lymphatic drainage
(Not exactly tongue, but commonly asked with it)
Lesion of the vagus nerve, uvula deviates away from the lesion.
Anterior 2/3 → First arch
Posterior 1/3 → Third arch
Posteriormost part → Fourth arch
Mucosal fold attaching the epiglottis to the tongue.
Small depressions between the median and lateral glossoepiglottic folds.
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