Pharynx – description, divisions, muscles, syntopy, vascular supply, innervation

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The pharynx is a muscular tube that connects the nasal cavity, middle ear, oral cavity, larynx and oesophagus; and is mainly used to transport air and food, immune defence (involved in Waldeyer’s tonsillar ring and perceive taste (contain taste buds) The pharynx is lined by stratified, non-keratinised squamous epithelium. It is divided into three sections (upper to lower level): nasophaynx, oropharynx and laryngopharynx.

  • The Pharynx

    The Pharynx

Nasopharynx (upper part)[edit | edit source]

  • Base to C2
  • Respiratory function
  • Superior to the soft palate; posterior expansion of the nasal cavity
  • Connected to the nasal cavity via choanae
  • Connected to middle ear via Eustachian tube
  • Connected to oral cavity via faucial isthmus
  • On the back wall of nasopharynx, lymphatic tissue known as pharyngeal tonsil can be found and lies superior to the opening of the Eustachian tube
  • Another lymphatic tissue known as Tubal Tonsil can be found close to the opening of Eustachian tube, on the lateral wall of nasopharynx
  • lined with respiratory epithelium (ciliates pseudostratified columnar epithelium, interspersed with mucous-secreting globes cells)

Oropharynx (middle part)[edit | edit source]

  • C2 to C4
  • Digestive function
  • Superior to the soft palate; inferior to the tongue (contains posterior 1/3 of tongue)
  • at the base of the tongue, lingual tonsils can be found
  • Within the tonsillar fossa, palatine tonsil can be found
  • Lateral to it are the palatoglossal and palatopharyngeal arches
  • involved in voluntary and involuntary reflex of swallowing (details see below)

Laryngopharynx (lower part)[edit | edit source]

  • C4 to C6 (connected inferiorly to oesophagus; communicated to larynx via laryngeal inlet)
  • Superior border is epiglottis
  • Inferior border is cricoid cartilage

Pharyngeal muscles[edit | edit source]

Superior pharyngeal constriction

  • Innervated by vagus nerve (CN10)
  • to propel food downward, separates nasopharynx and oropharynx
  • Origin: Pterygoid harmful us, Pterygomandibular raphe, Myloyoid line
  • Insertion: pharyngobasilar membrane and pharyngeal raphe

Middle pharyngeal constriction

  • Innervated by vagus nerve (CN10)
  • to propel food downward into oesophagus
  • Origin: greater and lesser horn of hyoid bone
  • Insertion: pharyngeal raphe

Inferior pharyngeal constriction

  • Innervated by vagus nerve (CN10)
  • to propel food downward, closes laryngeal inlet by elevating larynx
  • Origin: thyroid cartilage and lateral side of cricoid cartilage
  • Insertion: pharyngeal raphe

Stylopharyngeus

  • Innervated by glossopharyngeal nerve (CN9)
  • Elevates pharynx
  • Origin: styloid process of temporal bone
  • Insertion: thyroid cartilage

Palatopharyngeus

  • Innervated by vagus nerve (CN10)
  • narrows isthmus of faucets, depresses the soft palate, elevates pharyngeal wall towards the soft palate
  • Origin: palatine aponeurosis
  • Insertion: thyroid cartilage

Salpingopharyngeus

  • Innervated by vagus nerve (CN10)
  • elevates pharynx
  • Origin: cartilage of tube
  • Insertion: lateral wall of pharynx

Blood Supply[edit | edit source]

Arteries[edit | edit source]

  • Ascending pharyngeal artery , external carotid artery medial group
  • Ascending palatine artery , from facial artery of external carotid artery
  • Tonsillar artery (or tonsillar branch of facial artery)
  • Maxillary artery (branches of external carotid artery)
  • Lingual artery (branches of external carotid artery)

Veins[edit | edit source]

  • Pterygoid venous plexus
  • Facial vein
  • Internal Jugular Vein

Innervation[edit | edit source]

  • Motor and most sensory innervation is done by glossopharyngeal nerve

Muscular Innervation

  • Pharyngeal branches of vagus nerve (CN 10) except for stylopharyngeus
  • Stylopharyngeus - glossopharyngeal nerve (CN 9)

Sensory

  • Glossopharyngeal nerve (CN 9)
  • Anterior and superior of nasopharynx innervated by maxillary nerve (CN 2)

Swallowing Reflex[edit | edit source]

  • It is the voluntary initiation of swallowing
  1. Reflex closure of the airway
  2. Reflex transport of food bolus down the oesophagus; through the pharynx


Links[edit | edit source]

Bibliography[edit | edit source]

SNELL, Richard S. Clinical Anatomy by Regions. 8th Edition edition. 2004. ISBN 978-0-7817-6404-9.


Thieme, Atlas of Anatomy. Markus Voll et al. 4th edition. ISBN 978-1-68420-203-4

Sobotta, Atlas of Human Anatomy, Tables of Muscles, Joints, and Nerves. F. Paulsen and J. Waschke. 1st edition. ISBN 978-0-7020-5254-5

Sobotta, Anatomy Textbook. Jens Waschke et al. English Edition with Latin Nomenclature. ISBN 978-0-7020-6760-0

Atlas of Human Anatomy. Frank H. Netter. 7th Edition. ISBN 978-0-323-39322-5

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