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TONGUE
Tongue
• derived from 1st-4th branchial arches
• manipulates food for chewing and swallowing
• contains no bony supports for the muscles
– the extrinsic muscles of the tongue anchor the tongue
firmly to surrounding bones and prevent the mythical
possibility of 'swallowing' the tongue
• sensitive and kept moist by saliva, and is richly
supplied with nerves and blood vessels to help it
move
Anatomy
• made mainly of skeletal
muscle
• dorsum
– oral part (anterior twothirds of the tongue) that
lies mostly in the mouth
– pharyngeal part (posterior
third of the tongue), which
faces backward to the
oropharynx
– separated by a V-shaped
groove, which marks the
sulcus terminalis
Anatomy
Normal name
Anatomical name
Adjective
Tongue tip
Tongue blade
Apex
Lamina
Apical
Laminal
Tongue dorsum
Dorsum
Dorsal
Tongue root
Tongue body
Radix
Corpus
Radical
Corporeal
Extrinsic Muscles of the
Tongue
Muscle
From
Nerve
Function
Genioglossus
mandibl
e
hypoglossal
nerve
protrudes the tongue as well as depressing its center.
Hyoglosus
hyoid
bone
hypoglossal
nerve
depresses the tongue.
styloid
process
palatine
aponeur
osis
hypoglossal
nerve
pharyngeal
branch of
vagus nerve
Styloglossus
Palatoglossus
elevates and retracts the tongue.
depresses the soft palate, moves the palatoglossal
fold towards the midline, and elevates the back of
the tongue.
Intrinsic Muscles of the Tongue
• superior longitudinal muscle: assists in retraction of, or deviates
the tip of the tongue
– originates near the epiglottis, the hyoid bone, from the median
fibrous septum
• inferior longitudinal muscle: lines the sides of the tongue, and is
joined to the styloglossus muscle
• verticalis muscle: joins the superior and inferior longitudinal
muscles
• transversus muscle: divides the tongue at the middle
Pappilae
• The oral part of the tongue is covered with small
bumpy projections called papillae. There are four
types of papillae:
–
–
–
–
filiform (thread-shape)
fungiform (mushroom-shape)
circumvallate (ringed-circle)
foliate (leaf-shape)
• All papillae except the filiform have taste buds on
their surface
Blood Supply
• primarily from the lingual artery, a branch
of the external carotid artery.
• secondary blood supply to the tongue from
the tonsillar branch of the facial artery and
the ascending pharyngeal artery
Nerve Supply
• Motor innervation: hypoglossal nerve
– the palatoglossal muscle is innervated by the pharyngeal
branch of vagus nerve
• Sensory Innervation
– somatic sensations: lingual nerve, a major branch of the
mandibular nerve; also carries general sensation from areas
of the oral mucosa and gingiva of the lower teeth.
– taste sensation: facial nerve via the chorda tympani; also
carries parasympathetic fibers from the facial nerve to the
submandibular ganglion
– posterior one-third of the tounge: glossopharyngeal nerve
Function
• assists in forming the
sounds of speech
• it is the primary organ
of taste
– much of the surface of
the tongue is covered
in taste buds