The oral part of the tongue is also known as the anterior 2/3 of the tongue

Develops from the 2 lateral lingual swellings and tuberculum impar of the 1st pharyngeal arch—thus mucosa is innervated by the nerve of the 1st arch, which is the trigeminal nerve (lingual n.)

Has a dorsal and a ventral surface

The mucosa is keratinized stratified squamous epithelium

Is bounded posteriorly by the sulcus terminalis

A midline groove that travels anteriorly

Represents the location of the median septum that divides the tongue in halves

The septum is thicker posteriorly but thinner anteriorly

Papillae—there are 4 types of papillae on the dorsal surface of the tongue:

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  Filiform—lack taste buds

  • Most numerous type of papillae

  • Have thick keratin on epithelium, resulting in a rough surface for functional purposes

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  Fungiform—have taste buds that receive taste innervation from the facial nerve (chorda tympani branch)

  • Scattered throughout the dorsum of the oral part

  • Lack keratin on the epithelium

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  Foliate—have taste buds that receive taste innervation from the facial nerve (chorda tympani branch)

  • Are located on the sides of the tongue in 4–5 folds immediately anterior to the palatoglossal fold

  • Lack keratin on the epithelium

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  Circumvallate (vallate)—have taste buds that receive taste innervation from the glossopharyngeal nerve

  • Generally a nonkeratinized epithelium

  • Lie in a row immediately anterior to the sulcus terminalis

Papillae are raised projections that increase the surface area

5 basic types of taste are differentiated by the taste buds:

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  Bitter

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  Salt

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  Sweet

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  Sour

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  Umami

The mucosa is nonkeratinized stratified squamous epithelium

A midline fold of tissue

Connects the ventral surface of the tongue to the floor of the oral cavity

A swelling on both sides of the lingual frenulum at the tongue base

Marks the entrance of saliva from the submandibular glands into the oral cavity

Continuous with the sublingual folds overlying the sublingual glands on the floor of the oral cavity

Fimbriated folds

Lateral to the lingual frenulum

Can be observed through the mucosa between the plica fimbriata and the lingual frenulum

The pharyngeal part of the tongue is also known as the posterior 1/3 of the tongue

Develops from the hypobranchial eminence of the 3rd pharyngeal arch—thus mucosa is innervated by the nerve of the 3rd arch (the glossopharyngeal nerve)

The area immediately posterior to the palatoglossal folds (also called the anterior pillar of the fauces) is the oropharynx

Has a dorsal surface only

Does not possess any papillae

The mucosa is nonkeratinized stratified squamous epithelium

Large nodules of lymphatic tissue

Cover the pharyngeal surface of the tongue

Mucous membrane of nonkeratinized stratified squamous epithelium from the pharyngeal part and lateral wall of pharynx that reflects onto the anterior epiglottis, forming:

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  Median glossoepiglottic fold

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  2 lateral glossoepiglottic folds

The median glossoepiglottic fold is bordered by a depression on each side:

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  Vallecula

Connect the posterior portion of the pharyngeal part of the tongue with the epiglottis of the larynx

Superior fibers fan into the entire ventral surface of the tongue as they intermix with the intrinsic muscles)

Intermediate fibers fan out and rise upward as they pass posteriorly to intermingle with the dorsal, intrinisic muscle fibers of the tongue

Inferior fibers insert into the body of the hyoid via an aponeurosis

Protrusion of the tongue

Bilaterally —the 2 muscles will depress the central portion of the tongue, which makes the dorsal surface concave

Unilaterally —makes the tongue deviate to the contralateral side

The lingual n., hypoglossal n., and submandibular duct are located on the lateral surface of the hyoglossus m.

Some authors describe the chondroglossus as a separate muscle or as part of the hyoglossus

Anterolateral portion near the apex of the styloid process

Stylomandibular ligament

Longitudinal portion inserts into the dorsolateral part of the tongue to intermix with the inferior longitudinal m.

Oblique portion inserts into the dorsolateral portion of the tongue to intermix with the hyoglossus m.

Retrusion of the tongue

Elevation of the tongue, primarily lateral borders

Elevation of the root of the tongue

Narrows the oropharyngeal isthmus for deglutition