The Tongue

  • Overview:

    • The tongue is a mass of muscle that is almost completely covered by a mucous membrane:

      • It occupies most of the oral cavity and oropharynx.

    • It is known for its role in taste:

      • But it also assists with mastication (chewing), deglutition (swallowing), articulation (speech), and oral cleansing.

    • Five cranial nerves contribute to the complex innervation of this multifunctional organ.

    • The embryologic origins of the tongue first appear at 4 weeks’ gestation:

      • The body of the tongue forms from derivatives of the first branchial arch:

        • This gives rise to two lateral lingual swellings and one median swelling (known as the tuberculum impar):

          • The lateral lingual swellings slowly grow over the tuberculum impar and merge:

            • Forming the anterior two thirds of the tongue.

      • Parts of the second, third, and fourth branchial arches give rise to the base of the tongue.

    • Occipital somites give rise to myoblasts:

      • Which form the intrinsic tongue musculature.



  • Gross Anatomy:

    • From anterior to posterior:

      • The tongue has three surfaces:

        • Tip

        • Body

        • Base

    • The tip:

      • Is the highly mobile, pointed anterior portion of the tongue.

    • Posterior to the tip lies the body of the tongue:

      • Which has dorsal (superior) and ventral (inferior) surfaces.

    • The median sulcus of the tongue:

      • Separates the body into left and right halves.

    • The terminal sulcus, or groove:

      • Is a V-shaped furrow that separates the body from the base of the tongue:

      • At the tip of this sulcus is the foramen cecum, a remnant of the proximal thryoglosal duct.

    • The base of tongue contains the lingual tonsils:

      • The inferior most portion of Waldeyer’s ring.

  • Lingual papillae:

    • The surface of the body of the tongue derives its characteristic appearance from the presence of lingual papillae:

      • Which are projections of lamina propria covered with epithelium.

    • The four types of lingual papillae are as follows:

      • Vallate (circumvallate)

      • Foliate

      • Filiform

      • Fungiform

    • The vallate papillae (circumvallate) are flat, prominent papillae that are surrounded by troughs:

      • In humans, there are 8 to 12 vallate papillae, located directly anterior to the terminal sulcus:

        • The ducts of the lingual glands of von Ebner secrete lingual lipase into the surrounding troughs:

          • To begin the process of lipolysis.

    • The foliate papillae are small folds of mucosa (short vertical folds) located along the lateral surface of the tongue:

      • They are located on the sides at the back of the tongue:

      • There are four or five vertical folds, and their size and shape is variable.

      • They are covered with epithelium, lack keratin and so are softer, and bear many taste buds:

        • Approximately 1000 taste buds:

      • They are usually bilaterally symmetrical.

      • Sometimes they appear small and inconspicuous, and at other times they are prominent.

      • Because their location is a high risk site for oral cancer, and their tendency to occasionally swell, they may be mistaken as tumors or inflammatory disease.

      • Serous glands drain into the folds and clean the taste buds.

      • Lingual tonsils are found immediately behind the foliate papillae and, when hyperplastic, cause a prominence of the papillae.

    • The filiform papillae:

      • Are the most numerous of the lingual papillae.

      • They are fine, small, cone-shaped papillae covering most of the dorsum of the tongue.

      • They cover most of the front two-thirds of the tongue’s surface.

      • They appear as very small, conical or cylindrical surface projections, and are arranged in rows which lie parallel to the sulcus terminalis:

        • At the tip of the tongue, these rows become more transverse.

      • They are responsible for giving the tongue its texture and are responsible for the sensation of touch.

      • Unlike the other kinds of papillae, filiform papillae do not contain taste buds.

    • The fungiform papillae are mushroom shaped (generally red in color) and are dispersed most densely along the tip and lateral surfaces of the tongue:

      • Humans have approximately 200 to 300 fungiform papillae.

    • Each vallate, foliate, and fungiform papilla contains taste buds (250, 1000, and 1600 taste buds, respectively):

      • Each taste bud is innervated by several nerve fibers.

      • In humans:

        • All taste buds can perceive the five different tastequalities:

          • Salt

          • Sweet

          • Bitter

          • Acid

          • Umami.


  • Each taste bud consists of:

    • Taste receptor

    • Basal cell

    • Edge cell

  • When a taste molecule binds to a taste receptor, the receptor cell depolarizes:

    • Causing an influx of Ca++, which results in the release of an unknown neurotransmitter.

    • Following depolarization, the afferent neural pathway depends on the location of the taste bud that was stimulated:

      • In the anterior two thirds of the tongue:

        • The chorda tympani branch of the facial nerve (cranial nerve VII) is stimulated.

      • The lingual-tonsillar branch of the glossopharyngeal nerve (cranial nerve IX) relays taste information:

        • From the posterior third of the tongue (base of the tongue).

  • Taste fibers from the anterior two thirds of the tongue first travel with the lingual nerve and then are relayed to the chorda tympani nerve:

    • This nerve enters the temporal bone from the infratemporal fossa:

      • Where it joins the facial nerve and travels to the geniculate ganglion:

        • Where its pseudounipolar cell bodies are located.

    • From the geniculate ganglion:

      • The taste fibers travel in the nervus intermedius to the nucleus of the solitary tract located in the medulla oblongata.

  • Similarly:

    • Taste fibers from the posterior one third of the tongue travel with the lingual-tonsillar nerve:

      • To the inferior glossopharyngeal ganglion and then to the nucleus of the solitary tract located in the medulla oblongata.

  • Second-order neurons then project taste fibers to the parabrachial nucleus of the pons.

  • The central tegmental tract carries taste sensation from the pons to the thalamus.

  • The pathway ends in the:

    • Frontal operculum and insular cortex.




Rodrigo Arrangoiz MS, MD, FACS a head and neck surgeon and is amember of Center for Advanced Surgical:


He is first author on some publications on oral cavity cancer:


• General surgery:

• Michigan State University:

• 2004 al 2010

• Surgical Oncology / Head and Neck Surgery / Endocrine Surgery:

• Fox Chase Cancer Center (Filadelfia):

• 2010 al 2012

• Masters in Science (Clinical research for health professionals):

• Drexel University (Filadelfia):

• 2010 al 2012

• Surgical Oncology / Head and Neck Surgery / Endocrine Surgery:

• IFHNOS / Memorial Sloan Kettering Cancer Center:

• 2014 al 2016





























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