External Pharynx

Gross Anatomy

Prevertebral and Lateral Vertebral Regions; Interior of Pharynx


Anatomy Tables for Today's Topic


Bones
Muscles
Nerves
Arteries
Veins
Lymphatics
Viscera
Fascia

Bones

Bone/Cartilage Structure Description Notes
hyoid a "U"-shaped bone consisting of several parts: body, 2 greater horns, 2 lesser horns the hyoid bone ossifies completely in middle life; the body articulates with the greater horns via cartilage and with the lesser horns via fibrous joints prior to ossification; an important site for muscle attachments (suprahyoid and infrahyoid muscle groups)
body the middle portion of the "U"-shaped bone the body of the hyoid bone articulates with the greater horns posteriorly
greater horn (cornu) posteriorly directed limbs of the "U"-shaped bone each greater horn articulates with the body and lesser horns anteriorly; origin of middle pharyngeal constrictor m. and hyoglossus m.
lesser horn (cornu) articulates with the greater horn at its junction with the body the inferior end of the stylohyoid ligament attaches to the lesser horn
sphenoid an irregularly shaped bone forming the central portion of the skull it has many parts, including a body, greater wing, lesser wing and pterygoid plates
pterygoid process process that projects inferiorly from the junction of the body & greater wing of the sphenoid bone it has several parts: lateral & medial pterygoid plates, hamulus, pterygoid fossa, scaphoid fossa; the pterygoid plates are separated by the large pterygoid fossa throughout most of their length, and by the small scaphoid fossa superiorly
lateral pterygoid plate thin plate of bone that projects posterolaterally from the pterygoid process it is the attachment site of the lateral & medial pterygoid muscles (lateral pterygoid m. on its lateral surface, medial pterygoid m. on its medial surface)
medial pterygoid plate thin plate of bone that projects posteriorly from the pterygoid process it is the attachment of the superior pharyngeal constrictor m. & the pharygobasilar fascia
scaphoid fossa an oval depression at the superior end of the lateral pterygoid plate it is the site of origin of the tensor veli palatini m.
pterygoid hamulus hook-like projection from the inferior end of the medial pterygoid plate it acts as a pulley for the tendon of the tensor veli palatini m.
mandible the U-shaped bone forming the lower jaw contains the inferior teeth; formed from the mesenchyme of the 1st pharyngeal arch, and its muscles are innervated by the nerve of the 1st arch (mandibular division of cranial nerve V)
mylohyoid line the ridge running obliquely from posterosuperior to anteroinferior on the medial surface of the body of the mandible attachment site for the mylohyoid muscle; the submandibular gland is located inferior to this line and the sublingual gland is located superior to this line
occipital the bone forming the posterior surface of the skull it articulates superolaterally with the parietal bones through the lambdoid suture, anteroinferiorly with the temporal bone and anteriorly with the body of the sphenoid bone
pharyngeal tubercle projection located anterior to the foramen magnum attachment site for the superior pharyngeal constrictor m.
palatine the bone that forms the posterior part of the hard palate paired; failure of the perpendicular plates to fuse during development leads to a midline defect (cleft palate)
horizontal plate the portion of the palatine bone that forms the posterior 1/3 of the hard palate paired; the two horizontal plates meet at the midline
cricoid cartilage the inferior and posterior cartilage of the larynx; it forms a complete cartilaginous ring; its arch projects anteriorly and its lamina is broad and flat posteriorly connected: above to the thyroid cartilage via the inferior horn of the thyroid cartilage, to the conus elasticus, to the arytenoid cartilages which sit atop the lamina; connected below to the first tracheal ring via the cricotracheal ligament
epiglottis the superior part of the larynx epiglottic cartilage is covered by a mucous membrane
thyroid cartilage the large anterior cartilage of the larynx; it has several parts: laminae (2), superior horns (2), inferior horns (2), oblique line, superior thyroid notch, connected above to the hyoid bone via the thyrohyoid membrane; connected below to the cricoid cartilage via the inferior horn of the thyroid cartilage; connected posteriorly: to the arytenoid cartilage via the vocal ligament and thyroarytenoid m., to the epiglottic cartilage via the thyroepiglottic ligament; it tilts anteriorly to increase the length of the vocal ligament and raise the pitch of the voice

Muscles

Muscle Origin Insertion Action Innervation Artery Notes
constrictor, inferior pharyngeal oblique line of the thyroid cartilage, lateral surface of cricoid cartilage midline pharyngeal raphe constricts pharyngeal cavity vagus (X), via the pharyngeal plexus, with aid from the superior laryngeal and recurrent laryngeal nerves ascending pharyngeal a., superior thyroid a., inferior thyroid a. the most external of the three pharyngeal constructor mm.
constrictor, middle pharyngeal lesser and greater horns of the hyoid bone and the inferior part of the stylohyoid ligament midline pharyngeal raphe constricts the pharyngeal cavity vagus (X), via the pharyngeal plexus ascending pharyngeal a. of the three pharyngeal constrictors, this one is intermediate in both superior/inferior position and depth
constrictor, superior pharyngeal medial pterygoid plate, pterygoid hamulus, pterygomandibular raphe, mylohyoid line of mandible pharyngeal tubercle and midline pharyngeal raphe constricts the pharyngeal cavity vagus (X), via the pharyngeal plexus ascending pharyngeal a. the most internal of the three pharyngeal constructor mm.
palatoglossus palatine aponeurosis side of the tongue, entering it from above elevates and retracts the tongue vagus nerve (X) via the pharyngeal plexus tonsilar branch of the facial a., ascending pharyngeal a. although palatoglossus sounds like a tongue muscle (and would therefore be innervated by XII), it is a palatal muscle innervated by X
palatopharyngeus posterior margin of the bony palate and the palatine aponeurosis posterior wall of the pharynx and the posterior margin of the thyroid cartilage elevates the larynx vagus nerve (X) via pharyngeal plexus ascending pharyngeal a. palatopharyngeus is part of the inner longitudinal muscle layer of the pharynx
salpingopharyngeus inferior surface of the anteromedial end of the auditory tube cartilage pharyngeal wall and superior border of the thyroid cartilage along with the palatopharyngeus m. elevates the larynx vagus nerve (X) via the pharyngeal plexus ascending pharyngeal a. like other muscles of the pharyngeal wall, salpingopharyngeus is derived from the fourth pharyngeal arch
stylopharyngeus medial side of the styloid process superior border of the thyroid cartilage and also into the pharyngeal wall elevates the larynx glossopharyngeal nerve (IX) ascending pharyngeal a. stylopharyngeus, the only muscle innervated by IX, is the only muscle of the pharyngeal wall NOT innervated by the vagus (X) nerve; it is a derivative of the third pharyngeal arch

Nerves

Nerve Source Branches Motor Sensory Notes
glossopharyngeal n. medulla: spinal trigeminal nucleus from the superior ganglion (GVA); nucleus solitarius from the inferior ganglion (SVA); nucleus ambiguus (SVE); inferior salivatory nucleus (GVE - preganglionic parasympathetic) tympanic nerve to the tympanic plexus and lesser petrosal n., carotid sinus n., stylopharyngeus brs., pharyngeal brs. SVE: stylopharyngeus; GVE: secretomotor to the parotid gland (preganglionic parasympathetic via the tympanic n. to the lesser petrosal n. to the otic ganglion; postganglionic parasympathetic via the auriculotemporal n.) GVA: carotid body, carotid sinus, pharynx, middle ear; GSA: skin of the external ear; SVA: taste from the posterior 1/3 of the tongue also known as: CN IX, 9th cranial nerve; the glossopharyngeal n. exits the posterior cranial fossa by passing through the jugular foramen;it may penetrate the stylopharyngeus m.
pharyngeal plexus motor contributed by the vagus n. (X); sensory contributed by the glossopharyngeal n. (IX), vasomotor contributed by the superior cervical sympathetic ganglion no named branches vagus: all muscles of the pharynx except stylopharyngeus; sympathetic: smooth muscle in the pharyngeal vasculature glossopharyngeal: mucous membrane lining the pharynx the muscles of the pharyngeal wall are skeletal m. derived from the mesenchyme of the 4th pharyngeal arch
of the pterygoid canal formed by the union of the greater petrosal n. (preganglionic parasympathetic) and the deep petrosal n.(postganglionic sympathetic) ends in the pterygopalatine ganglion (parasympathetic) secretomotor (parasympathetic) to: lacrimal gland and mucous glands of nasal cavity and maxillary sinus; sympathetic innervation to vascular smooth muscle in the same region none contains: preganglionic axons of the greater petrosal n. bound for pterygopalatine ganglion where they will synapse; postganglionic sympathetic axons of the deep petrosal n. which will pass through the pterygopalatine ganglion without synapsing
sympathetic chain ganglia, cervical preganglionic sympathetic fibers arrive via white rami communicantes of ventral primary rami of spinal nerves T1-T5 postganglionic sympathetic depart via gray rami communicans to cervical spinal nn.; internal and external carotid nn.; cervical cardiac brs. dilator pupillae m.; vascular smooth muscle; arrector pili muscles and sweat glands of head and neck; heart and lungs pain from viscera located parallel to the vertebral bodies in the neck; there are no white rami communicantes at cervical levels
vagus n. medulla: dorsal motor nucleus (GVE preganglionic parasympathetic); inferior ganglion (GVA); nucleus ambiguus (SVE); superior ganglion (GSA); inferior ganglion(SVA) auricular br., pharyngeal br., superior laryngeal, superior and inferior cervical cardiac brs., recurrent laryngeal n., thoracic cardiac brs., brs. to the pulmonary plexus, brs. to the esophageal plexus, anterior and posterior vagal trunks SVE: intrinsic muscles of the larynx, pharynx (except stylopharyngeus), and palate (except tensor veli palatini); GVE: smooth muscle of the respiratory tree & gut (proximal to the left colic flexure), heart; secretomotor: mucous glands of the larynx, respiratory tree, pharynx and gut; secretomotor to digestive glands GSA: skin of the external auditory meatus; GVA: viscera of head, neck, thorax & abdomen proximal to the left colic flexure; SVA: taste from the epiglottis also known as: CN X, 10th cranial nerve; the vagus n. passes through the jugular foramen to exit the posterior cranial fossa; vagus means "wanderer" in reference to its extensive distribution to the body cavities

Arteries

Artery Source Branches Supply to Notes
ethmoidal, anterior ophthalmic a. anterior meningeal a., anterior septal br., anterior lateral nasal br. anterior ethmoidal air cells, frontal paranasal sinus, dura mater in the anterior cranial fossa, nasal mucosa, olfactory nerves anterior ethmoidal a. leaves the orbit through the anterior ethmoidal foramen, then runs forward on the cribriform plate
ethmoidal, posterior ophthalmic a. no named branches posterior ethmoidal air cells; olfactory nerves posterior ethmoidal a. leaves the orbit through the posterior ethmoidal foramen
palatine, ascending facial a. no named branches superior pharyngeal constrictor, soft palate, palatine tonsil ascending palatine a. shares supply of the tonsil bed with 4 other aa. (see also: tonsillar br. of the facial a., palatine br. of the ascending pharyngeal a., tonsillar br. of the dorsal lingual a., tonsillar br. of the descending palatine a.)
pharyngeal, ascending external carotid pharyngeal brs., inferior tympanic, posterior meningeal pharynx arises from the medial side of the external carotid a. close to the birfurcation
posterior septal sphenopalatine a. (several small brs.) no named branches posterior aspect of the nasal septum posterior septal a. supplies the mucous membrane of the nasal septum
sphenopalatine maxillary a. posterior lateral nasal brs., posterior septal brs. posterolateral nasal wall, posteroinferior nasal septum, hard palate behind the maxillary incisor teeth sphenopalatine a. accompanies the nasopalatine n.

Veins

Vein Tributaries Drains Into Regions Drained Notes
plexus, pharyngeal venous unnamed tributaries that drain the pharyngeal wall internal jugular pharynx connects with the pterygoid venous plexus
plexus, pterygoid venous descending palatine v., sphenopalatine v., infraorbital v., posterior superior alveolar v., anterior deep temporal v., posterior deep temporal v., middle meningeal v., masseteric v., inferior alveolar v. maxillary v. meninges, nasal cavity, infratemporal fossa valveless; the pterygoid plexus is connected with the cavernous sinus and the pharyngeal venous plexus

Lymphatics

Structure Location Afferents from Efferents to Regions drained Notes
tonsil, pharyngeal roof and posterior wall of the nasopharynx lymphatic vessels of the wall of the pharynx superior deep cervical nodes "guards" the entrance to the nasopharynx pharyngeal tonsil is part of the tonsillar ring  eyer); also known as: adenoids
tonsil, tubal pharyngeal recess lymphatic vessels of the torus tubarius and auditory tube superior deep cervical nodes "guards" the entrance to the nasopharynx tubal tonsil is located at the pharyngeal orifice of the auditory tube

Viscera

Organ Location/Description Notes
esophagus the portion of the gastrointestinal tract between the pharynx and the stomach connects: superiorly with laryngopharynx at lower border of cricoid cartilage; inferiorly it passes through diaphragm at the T10 vertebral level to reach the stomach; the upper 1/3 is skeletal muscle innervated by the recurrent laryngeal, the lower 2/3rds is smooth muscle innervated by the vagus nn. via the esophageal plexus
laryngopharynx the portion of the pharynx located posterior to the laryngeal inlet and the posterior wall of the larynx connects: superiorly with oropharynx at the superior border of epiglottis, anteriorly with the larynx through laryngeal inlet, inferiorly with the esophagus at the lower border of the cricoid cartilage; laryngopharynx contains the piriform recesses which are lateral to the aryepiglottic folds
nasopharynx the portion of the pharynx located posterior to the posterior nasal apertures and superior to the soft palate nasopharynx communicates; anteriorly with the nasal cavity through the choanae and inferiorly with the oropharynx; it contains the torus tubarius, pharyngeal recess and pharyngeal tonsil
oropharynx the portion of the pharynx located posterior to the palatoglossal arches of the oral cavity and inferior to the soft palate oropharynx communicates: anteriorly with oral cavity thr  oropharyngeal isthmus (palatoglossal arch), superiorly with the nasopharynx through pharyngeal isthmus (posterior margin of soft palat inferiorly with the laryngopharynx at the superior margin of epiglottis; it contains the palatine tonsil which is located in the tonsilar bed (between the palatoglossal arch and the palatopharyngeal arch)
palatoglossal fold fold of mucosa covering the palatoglossus m. palatoglossal fold marks the anterior boundary of the bed of the palatine tonsil
palatopharyngeal fold fold of mucosa covering the palatopharyngeus m. palatoglossal fold marks the posterior boundary of the bed of the palatine tonsil
pharyngeal recess space located posterior to the torus tubarius in nasopharynx the pharyngeal tonsil is located in this region
pharynx the space posterior to the nasal cavity, oral cavity and larynx divided into 3 parts: nasopharynx, oropharynx and laryngopharynx; the airway and the pathway of ingested foods and liquids cross at this location
piriform recess shallow depression located lateral to the aryepiglottic fold in the laryngopharynx the internal branch of the superior laryngeal n. is located immediately deep to the mucosa in this region; also known as: piriform fossa
salpingopharyngeal fold mucosal fold descending from the posterior margin of the torus tubarius salpingopharyngeal fold contains the salpingopharyngeus m.
torus tubarius mucosal fold covering the anteromedial end of the auditory tube cartilage torus tubarius projects toward the midline from the lateral wall of the nasopharynx

Fascia

fascia, alar anterior lamina of the prevertebral fascia, attaching anteriorly to visceral fascia behind esophagus in the superior thorax alar fascia separates the retropharyngeal space above from the posterior mediastinum below
fascia, buccopharyngeal posterior part of the visceral fascia of the neck buccopharyngeal fascia lies behind the pharynx and esophagus
fascia, pharyngobasilar submucosa of the pharynx pharyngobasilar fascia is attached to the base of skull and is best seen above the superior edge of the superior pharyngeal constrictor m.
fascia, prevertebral deep fascia surrounding vertebral column and associated muscles prevertebral fascia covers the scalene mm. where it is called scalene fascia

Other Tables of Interest:

All Anatomy Tables

Tables Organized by System Tables Organized by Region


Some of the material presented in these tables is contained in the book:
MedCharts Anatomy by Thomas R. Gest and Jaye Schlesinger
Published by ILOC, Inc., New York. Copyright 1995.

Content of these tables has been edited for use in this course by Patrick W. Tank, Ph.D.
Copyright 2007, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences.

Unauthorized use is prohibited.