The pharynx is divided into 3 parts - nasopharynx, oropharynx, and laryngopharynx. It has relationships superiorly, inferiorly, posteriorly, and laterally. The muscles of the pharynx include the 3 constrictor muscles and 3 levator muscles. Key structures in the pharynx include the tonsils, palatoglossal and palatopharyngeal arches, and pyriform sinuses. The pharynx is innervated by branches of the glossopharyngeal and vagus nerves and drains lymphatically into deep cervical lymph nodes.

1. Pharynx
Dr. A. Aktar

2. Learning Objectives
• What are the boundaries, contents, muscles, fascia, vasculature, and
innervation of the pharynx
• What are the relationships of the pharynx
• What are the origins and insertions of the muscles
• What is the retropharyngeal and lateropharyngeal space
• What are the functions of the glossopharyngeal n. (CN IX) and vagus n. (CN X) in
this region?

3. Pharynx
• Behind the oral & nasal cavities
• Superior to the esophagus
• Superior & posterior to the larynx
• Part of digestive system + transmission zone for the respiratory systme
➔ Respiration can be from mouth & from nose
• Has a role in vocalisation
• Has 2 sets of muscles which determine
shape of lumen
• Muscle arrangmenet:
• Inner layer longitudinal
• Outer layer circular

4. • 13-15 cm
• Base of cranium
to
• 6th cervical vertebra

5. Superior Relations
- Corpus of sphenoid bone
- Basilar part of occipital
bone

6. Inferior Relations
Oesophagus

7. POSTERIOR RELATIONS
• Retropharyngeal space
• Cervical vertebra
• Prevertebral muscles
• Deep cervical fasia

9. LATERAL
RELATIONS
• Medial pterygoid m.
• Interior border of parotid
gland
• Parapharyngeal space
➢ a. carotis interna
➢ v. jugularis interna
➢ n. glossopharyngeus
➢ n. vagus
➢ n. accessorius
➢ n. hypoglossus
➢ truncus sympathicus

10. LATERAL RELATIONS
• Ext. carotid a.
• Sup. thyroid a.
• Lingual a.
• Lateral lobes of
thyrooid gland
• Thyroid cartilage

11. ANTERIOR RELATIONS
Choana
Isthmus fauces
Laryngeal inlet

12. Parts of Pharynx
• Conventionally described in 3 parts:
Nasopharynx - behind nasal cavity
Oropharynx - behind oral cavity
Laringopharyx - behind larynx
A.k.a. Hypopharynx

13. Nasopharynx
• Posterior to nasal cavity
• Widest part of pharynx
• Level: Base of skull – C2
(Above level of soft palate)
• Choana – singular
• Choanae – plural
• Posterior nasal aperture -
posterior (choanae) opens to the
nasopharynx

15. Pharyngotympanic Tube
A.k.a. Eustachian tube
• Links nasopharynx to middle ear
• Opens on lat. wall of
nasopharynx, app. at level of
inf. nasal concha
• Adults app. 35 mm long
& 3 mm in diameter
• Filled with air
• Not in direct contact
w/ atmosphere
• Normally collapsed.
Gapes open w/ swallowing & w/ positive pressure

16. Mucosal Folds on Latera Wall: Torus of the Auditory Tube
• A.k.a. Tubal Elevation, a.k.a. Torus Tubarius
• Base of cartilaginous part of auditory tube lies directly under mucous
membrane of nasal part of pharynx
• Forms an elevation, torus tubarius -- cushion -- behind pharyngeal opening of
the auditory tube

17. Nasopharynx – Mucosal Folds on Lateral Wall:
Salpingopharyngeal Fold
• Vertical fold of mucous membrane
• Extends from inf. end of torus tubarius along wall of pharynx
• Contains salpingopharyngeus m.
• Salpingopharyngeus m. arises from inf. part of cartilage of auditory tube in nasal
cavity and passes downward into post. pharyngeal wall
Salpingopalatine fold
• A smaller fold, in front of salpingopharyngeal fold
• Stretches from superior part of torus to the palate

20. Nasopharynx: Mucosal Folds
Torus Levatorius a.k.a. Levator Elevation
• Mucous membrane elevation produced by levator veli palatini m.

22. NASOPHARYNX
Pharyngeal isthmus
• Passageway from nasopharynx to
oropharynx
• Closed during swallowing -
elevation of soft palate +
contraction of palatopharyngeus m.
• Passavant cushion
• Small prominence in post. pharynx,
formed from a focal bulge of
superior pharyngeal constrictor
m.m. during swallowing.
• «Cushion" opposes the soft palate
during swallowing & is part of
seal btwn soft palate & pharynx
• Prevents nasopharyngeal reflux
• What happens when you laugh during
drinking (swallowing) ?

23. Oropharynx
• Level: C2 - C3 vertebra
• Includes base of tongue & soft palate

24. Oropharynx
- Anteriorly communicates
w/ oral cavity thru
oropharyngeal isthmus
(palatoglossal arch)
-Lat wall: Palatoglossal &
palatopharyngeal
arches
-Palatine tonsil btwn
palatoglossal &
palatopharyngeal
arches
-Isthmus of fauces: Cavity
located btwn palatoglossal
& palatopharyngeal
arches
Sup.: soft palate
Inf: root of tongue.

25. Oropharynx
Palatoglossal arches:
Lat wall of oropharynx
A.k.a. Anterior pillar of the fauces
• Runs downward, lateral, and forward to the side of the base of the tongue
• Formed by projection of palatoglossus muscle w/ its mucous membrane
• Is the anterior border of the isthmus faucium
• Marks border btwn mouth & pharynx

26. Oropharynx
Palatopharyngeal
Arches:
A.k.a. Posterior pillar of
fauces
• Larger & projects farther
toward middle line than
palatoglossal arch
• Runs downward, lateral-
ward & backward to side
of pharynx
• Formed by projection of
Palatopharyngeal m. & its
mucous membrane

27. Oropharynx
Isthmus of the fauces a.k.a. Oropharyngeal Isthmus
• Bounded superiorly by soft palate, laterally by palatoglossal &
palatopharyngal arches, & inferiorly by root of tongue

28. Oropharynx
Palatoglossal & Palatopharyngeal Arches:
➔ The two pillars 
• Approximation of the arches due to the contraction of the palatoglossal
muscles constricts the isthmus
→ Essential to swallowing
• Deglutition

29. Waldeyer's Tonsillar Ring
• An arrangement of lymphoid tissue in the pharynx
• Surrounds naso-and oropharynx
• Some located above & some below the soft palate & to the back of
the oral cavity
Consists of (from top to bottom):
– 1 pharyngeal tonsil (a.k.a. adenoid)
– 2 tubal tonsils
– 2 palatine tonsils
– 1 lingual tonsil

30. Nasopharynx – Features on Lateral Wall
Tubal Tonsils
A.k.a. Eustachian tonsils, a.k.a. Gerlach’s tonsils
• Bilateral. Immediately posterior to the torus tubarius
• In the fossa of Rosenmüller (pharyngeal recess)
• Due to their closeness, sometimes also called the tonsil of (the) torus tubarius
• Located posterior
to the opening
of the Eustachian tube
• Lined by respiratory
epithelium

31. NASOPHARYNX
Roof & Posterior Wall
Pharyngeal Tonsil (Adenoid)
• Situated superior-posteriorly to the torus tubaris, in the roof of nasopharynx
• ‘Screens’ the air that enters through the nostrils
• Lined by pseudo-stratified ciliated columnar epithelium(respiratory epithelium).
• Unlike the other tonsils, there are no crypts
(invaginations in the surface of the tonsil)

32. PALATINE TONSIL
• On lateral wall of oropharynx
• Btwn palatoglossal &
palatopharyngeal arches - area
called tonsillar bed
• Has capsule which is laterally
related to sup. constrictor m. +
styloglossus m.
Arteries:
• Tonsillar artery (br. of facial a.)
• Lingual a + asc. palatine a
• Asc. pharyngeal a.
• Paratonsillar vein - may cause
excessive hemorrhage during
tonsillectomy
Nerves:
• Maxillary n., glossopharyngeal n.

34. LARYNGOPHARYNX
• Level: C3-C6 vert.
• Piriform recess
(fossa)
• Int. branch of
superior laryngeal n.
located under
mucosa

35. Laryngopharynx
Pyriform Recess
• On either side of laryngeal opening
• A.k.a. piriform sinus, piriform fossa, or smuggler's fossa
• "piriform," means "pear-shaped
• Bounded medially by aryepiglottic fold, laterally by thyroid cartilage & thyrohyoid
membrane
• Internal laryngeal nerve: Branch of
superior laryngeal n. Lies under mucosa
• The internal laryngeal nerve supplies
sensation to the area. May be damaged
if the mucosa is inadvertently punctured.

36. Laryngopharynx
Pyriform Recess
• Common place for food to become trapped
• Debris initiates throat clearing response

38. Laryngopharynx
Vallecula
• Depression just behind the root of the tongue between the medial and lateral
glosso-epiglottic folds
• Serve as "spit traps"; saliva is temporarily held in the valleculae to prevent
initiation of the swallowing reflex.
Clinical Correlate
• Important reference landmark used during intubation of the trachea. The
procedure requires the blade-tip of a laryngoscope to be placed as far as
possible into the vallecula in order to facilitate directly visualizing the glottis
https://www.youtube.com/watch?v=h_rWqf-Y8tc

39. Internal
branch of
superior
laryngeal n.

40. Layers of Pharynx
1- Mucosa
2- Fibrous layer
-Deficient at base of skull. Here called pharyngobasilar fascia
- Posteriorly forms: Pharyngeal Raphe
- Pharyn. tubercle of occipital bone)
3- Muscular layer (3 constrictors+ 3 levators)
4-Buccopharyngeal fascia
• Retropharyngeal space
• Prevertebral fascia

41. Raphe - Meaning
• The Greek word for a seam
• A groove, ridge, or seam in an organ or tissue,
typically marking the line where two halves fused in the embryo
• Pharyngeal Raphe

42. Pharyngobasilar Fascia
• Forms above superior pharyngeal constrictor m.
• Attaches to basilar part of occipital bone, petrous part of temporal bone (medial to
the pharyngotympanic tube), posterior border of medial pterygoid plate, and
the pterygomandibular raphe
• Diminishes in thickness inferiorly
• Posteriorly, it is reinforced by the pharyngeal raphe
• Reinforces the pharyngeal wall where muscle is deficient
• https://doctorlib.info/anatomy/lasts-anatomy-regional-and-
applied/74.html

44. Muscles of Pharynx
1- CONSTRICTORS (3)
2- LEVATORS (3)
CONSTRICTORS - circular
• Superior Constrictor m:
Level of nose & oral cavity
• Middle Constrictor m:
Level of hyoid bone
• Inferior Constrictor m:
Level of cricoid & thyroid cartilages
• Ridge of Passavant:
Palatopharyngeal sphincter
Part of sup. constrictor m.

45. Constrictor Muscles
• constrictor pharyngis superior
• constrictor pharyngis medius
• constrictor pharyngis Inferior
Raphe pharyngis –
tuberculum pharyngeum

46. Muscles of Pharynx
LEVATORS - longitudinal
• Stylo-pharyngeus m.
• Palato-pharyngeus m.
• Salpingo-pharyngeus m.
• Innervation: Pharyngeal plexus of nn
• Except:
Stylopharyngeus m. : CN IX
Glossopharyngeal n.

47. Levator Muscles

49. Sensory Nerves of Pharynx
• Nasopharynx: Maxillary n.
• Oroph + Laryngopharynx:
Glossopharyngeal n. & vagus n.

50. Arteries & Veins of Pharynx
• Ascending. Pharyngeal a. (Ext. Carotid.a.)
• Asc. palatine a. (Facial a.)
• Tonsillar a. (Facial a.)
• Greater palatine a. (Maxillary. a)
• Pharyngeal br. (Maxillary a.)
• The artery of pterygoid canal (Maxillary a.)
• Veins: Pharyngeal plexus ➔ Int. Jugular v. + Facial v.

51. Pharyngeal Plexus
• Network of nerve fibers
innervating most of palate &
pharynx
• Located on surface of middle
pharyngeal constrictor muscle
Sources:
• Glossopharyngeal n. CN IX & CN
X vagus pharyngeal branches -
sensory
• Vagus n. CN X - pharyngeal
branches - motor
• Cranial part of Accessory
nerve (CN XI) - motor
• Except stylopharyngeus : CN IX
• Superior cervical
ganglion sympathetic fibers -
vasomotor

52. Pharyngeal Plexus - EXCEPTIONS
• Nasopharynx above pharyngotympanic tube & torus tubarius - sensory: CN V2
• Motor : Stylopharyngeus by a branch of CN IX
Pharyngeal Glands’ Innervation
• Pterygopalatine ganglion (PS ganglion in pterygopalatine fossa)

53. Lymphatic Drainage
of Pharynx
-Retropharyngeal
-Paratracheal
-Infrahyoid
Deep cervical lymph nodes
Palatine tonsil:
Jugulodigastric node
(Angle of mandible-stclm m.
Deep cervical lymph nodes

57. Major Compartments of the Head

58. Pharynx
Major Compartments of the Head

59. References
• Standring S (2020) Gray's Anatomy: The Anatomical Basis of Clinical Practice, 42nd Edition
• Dalley A. F. (2022) Moore's Clinically Oriented Anatomy. 9th Edition
• Drake R.L. (2019) Gray's Anatomy for Students: 4th Edition
• Paulsen F. (2109) Sobotta Clinical Atlas of Human Anatomy, one volume, English 1st Edition
• Scheunke M. (2020) Atlas of Anatomy, Head, Neck, and Neuroanatomy 3rd Edition. Thieme
• Gilroy M., (2020) Atlas of Anatomy 4th Edition, Thieme