oral cavity. gross anatomy and histology of the tongue and

Oral cavity. Gross anatomy and histology

of the tongue and salivary glands.

Sándor Katz M.D.,Ph.D.

Oral cavity

Boundaries:

• Anterior wall: lips

• Superior wall: hard and soft palates

• Inferior wall: mylohyoid muscle

• Lateral wall: cheeks (buccinator muscles)

Parts:

• vestibule• oral cavity proper• isthmus of fauces

Vestibule and oral cavity proper

hard palate

soft palate

Isthmus of fauces

palatine tonsil

Isthmus of fauces

Tongue

1: dorsum

4: apex

2: root

3: body

Tongue

Foramen cecum: Developmental remnant of the thyroglossal duct (for the descensus of the thyroid gland).

Tongue

Tongue

epiglottic valleculae

Tongue - muscles (visceral striated)

Tongue - muscles

Tongue - muscles

Tongue - muscles

hyoglossus

styloglossus

Tongue - muscles

Tongue - muscles

Tongue - muscles

Tongue - muscles

Tongue - motor innervation

Tongue - sensory innervation

General sensation:• Anterior two-thirds: lingual

nerve• Posterior one-third:

glossopharyngeal nerve

Taste sensation:• Anterior two-thirds: chorda

tympani (from facial nerve)• Posterior one-third:

glossopharyngeal nerve

Tongue - blood supply

Lingual artery:• Deep lingual

artery• Sublingual

artery

Lingual vein deep lingual veinretromandibular veininternal jugular vein

Pirogov’s triangle(perfect place to ligate the lingual artery)

Boundaries:

• posterior edge of mylohyoid

• posterior belly of digastric

• hypoglossal nerve

Content: lingual artery

Histology of the tongue

Covering epithelium:

• stratified non-keratinized squamous epithelium

Papillae:

• filiform• fungiform• foliate• circumvallate

Histology of the tongue

Filiform papillae:

• conical, elongated projections

• covered by the highly keratinized stratified epithelium

• do not reprsent taste buds

• they have mechanical role

Histology of the tongue

Fungiform papillae:

• mushroom-shaped projections

• taste buds are presented in the stratified squamous epithelium on the dorsal surface of papillae

Histology of the tongue

Foliate papillae:

• consist of parallel low ridges separated by deep mucosal clefts

• taste buds are presented on the lateral sides

• small serous glands empty into the the clefts

Histology of the tongue

Circumvallate papillae:

• 8 to 12 papillae locate in front of the terminal sulcus

• taste buds are presented on the lateral sides

• each papilla surrounded by a moatlike invagination lined with stratified squamous epithelium

• von Ebner’s glands empty their serous secretion into the base of the moatlike invaginations

Histology of the tongue

• glands• striated visceral

muscle fibers• stratified non-

keratinized squamous epithelium

Taste buds

Sensory cells:• the most numerous cells• they show microvilli• at their base they form a synapse with the

processes of afferent sensory neurons• turnover time is about 10 days

Supporting cells: • they represent microvilli and tight junctions• turnover time is about 10 days

Basal cells: • small cells located in the basal portion, near

to the basal lamina• they are the stem cells for the two other cell

types

Salivary glands

Major salivary glands:

• Parotid

• Submandibular

• Sublingual

Minor salivary glands:They are 800-1000 glands located throughout the oral cavity within the submucosa.

Submandibular gland

• located in the submandibular trigone

• the facial artery is embedded to its medial/internal side

• the facial vein attaches to its external side

• the lingual nerve is presented at its superior side

• it is supplied by the lingual artery and innervated by the submandibular ganglion via lingual nerve

Submandibular gland

• the submandibular duct arises from its medial side and enters to the lateral lingual groove

Submandibular gland

• the submandibular ducts open onto the surface of the sublingual caruncles on either side of the lingual frenulum

Submandibular gland - lateral lingual sulcus

• V-shaped groove

• medial wall: hyoglossus

• lateral wall: mylohyoid

• contents from superior to inferior: lingual nerve, submandibular duct, hypoglossal nerve

Submandibular gland - histology

• mixed gland

• mostly serous acini

• Gianuzzi’s demilunes

Submandibular gland - histology

intercalatedduct

striated duct

Submandibular gland - histology

interlobular duct

Sublingual gland

• located on the upper side of the mylohyoid anterior to the submandibular gland

• their multiple small ducts empty into the submandibular duct as well as directly onto the floor of the mouth

• it is supplied by the sublingual artery and innervated by the submandibular ganglion via lingual nerve

Sublingual gland

• located on the upper side of the mylohyoid anterior to the submandibular gland

• their multiple small ducts empty into the submandibular gland as well as directly onto the floor of the mouth

• it is supplied by the sublingual artery and innervated by the submandibular ganglion via lingual nerve

Sublingual gland - histology

• mixed gland

• mostly mucous acini

• Gianuzzi’s demilunes

Parotid gland

• it is located in the parotid nest

• covered by the parotid fascia

• parotid duct travels underneath the zygomatic arch and at the anterior edge of the masseter turns to medial and pierces the buccinator than enters to the vestibule of the oral cavity at the level of second molar tooth

Parotid gland

• supplied by the external carotid artery and drained by the external jugular vein

• the facial and auriculotemporal nerves run through the gland

• the auriculotemporal nerve provides secretomotor (parasymathetic) innervation for it

Parotid gland - histology

• completely serous gland

Thank you for your attention.

References: Drake: Gray’s Anatomy for Students, 2nd ed.Standring: Gray’s Anatomy, 39th ed.Radiopaedia.orgThieme Atlas of Anatomy, Head and Neuroanatomy, 2nd ed.

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