For medical, nursing, and physiotherapy undergraduates, and postgraduates

1. PHARYNX
DR. SUNDIP CHARMODE
ASSISTANT PROFESSOR

2. OBJECTIVES
1. Structure, boundaries and features of various parts of pharynx
2. Muscles of pharynx with their attachments, action, nerve and blood
supply
3. Presenting parts, blood and nerve supply of Palatine tonsils
4. Structure, Parts, function of auditory tube
5. Clinical correlation

3. INTRODUCTION
• Musculo-membranous tube lined
internally by mucus membrane, that links
the oral and nasal cavities in the head to
the larynx and esophagus in neck.
• Extends from base of skull to the level of
6th cervical vertebra, where it becomes
continuous with the esophagus

4. PARTS OF PHARYNX
1. Nasopharynx
2. Oropharynx
3. Laryngopharynx

5. MEASUREMENTS
• Length – 12 – 14
• Width:
• Maximum of 3.5 cm at naso-pharynx
• Minimum at 1.5 cm at pharyngo-esophageal junction

6. SKELETAL FRAMEWORK
• The superior and anterior margins of the pharyngeal wall are attached to
bone and cartilage, and to ligaments.
• The two sides of the pharyngeal wall are welded together posterior in the
midline by a vertically oriented cord-like ligament - Pharyngeal raphe.
• Extends from pharyngeal tubercle (base of the skull) to level of 6th cervical
vertebra where it blends with connective tissue in the posterior wall of
oesophagus.

7. SKELETAL FRAMEWORK
• There is an irregular C -shaped line of pharyngeal wall attachment on
the base of the skull. The open part of the C faces the nasal cavities.

9. ATTACHMENT OF LATERAL PHARYNGEAL WALL
1. First part
2. Second part
3. Third part

10. RELATIONS OF PHARYNX
• Above: Supported by the body of sphenoid and basilar part of occipital
bone
• Below: Continuous with esophagus opposite C6 vertebra
• In front: Continuous with nasal cavity, oral cavity, and with larynx
• Behind:
• Upper six cervical vertebra and intervertebral disc
• Pre and para-vertebral muscles covered by prevertebral fascia
• Retro-pharyngeal space and its contents

11. RELATIONS OF PHARYNX
• On each side:
• Styloid process and styloid group of muscles
• Carotid sheath and its contents
• Lateral lobe of thyroid gland
• Lateral wall of nasopharynx communicates with tympanic cavity
through auditory tube

12. NASOPHARYNX/
EPIPHARYNX

13. INTERIOR OF NASO-PHARYNX
• Nasopharynx is situated behind the nasal cavity and above soft
palate.
• Boundaries are:
• Anterior wall
• Posterior wall
• Lateral walls
• Floor
• Roof

14. BOUNDARIES AND FEATURES
• Anterior wall: deficient and communicates with nasal cavity through
choanae
• Roof and posterior wall:
• Forms continuous surface, slopes backward and downward
• Supported by body of sphenoid, basilar part of occipital bone and
anterior arch of atlas

15. FEATURES
Roof and Posterior wall
1. Naso-pharyngeal tonsil
2. Pharyngeal bursa (pouch of
Luschka)
3. Pharyngeal hypophysis – roof,
cell are derived from
extension of Rathke’s pouch
Lateral wall
• Presents on each side following
features:
1. Pharyngeal opening of auditory
tube
2. Tubal elevation, Tubal tonsils, Two
mucous folds:
1. Salpingo-pharyngeal fold
2. Salpingo-palatine fold
3. Pharyngeal recess (Fossa of
Rosenmuller)

16. BOUNDARIES AND FEATURES
• Floor: Communicates with oropharynx through Pharyngeal Isthmus
• In front: Posterior surface and free margin of soft palate
• Behind: Passavant ridge formed by the palato-pharyngeal sphincter
and on each side by palato-pharyngeal arch containing muscle of
same name.

22. OROPHARYNX/
MESOPHARYNX

23. INTERIOR OF ORO-PHARYNX
• Oropharynx is situated behind the oral cavity and supported dorsally
by bodies of C2, C3 vertebra and contents of retro-pharyngeal space.

24. BOUNDARIES AND FEATURES
• In front: communicates with oral cavity through oro-pharyngeal
isthmus
• Below: communicates with laryngo-pharynx at the level of upper
border of epiglottis
• Lateral wall: presents on each side, palatine tonsil lodged in tonsillar
fossa

25. ORO-PHARYNGEAL ISTHMUS
• Boundaries:
• Above: soft palate
• Below: dorsal surface of
posterior third of tongue
• Each side: palato-glossal arch
with corresponding muscle

26. TONSILLAR FOSSA
• Boundaries:
• In front: palato-glossal arch with corresponding muscle
• Behind: palato-pharyngeal arch with corresponding muscle
• Apex: soft palate where both arches meet
• Base: dorsal surface of posterior third of tongue
• Lateral wall/floor of fossa- superior constrictor and styloglossus
covered by pharyngo-basilar fascia

29. LARYNGO-
PHARYNX/
HYPOPHARYNX

30. INTERIOR OF LARYNGO-PHARYNX
• Laryngo-pharynx extends from
upper border of epiglottis to lower
border of cricoid cartilage
• Supported from behind by bodies of
C4 to C6 vertebra, prevertebral
fascia and retropharyngeal space

31. BOUNDARIES AND FEATURES
• In front:
• Upper part: Presents laryngeal inlet, through which it
communicates with laryngeal cavity through oro-pharyngeal
isthmus
• Lower part: formed by posterior surface of arytenoids and lamina
of cricoid cartilages, covered by mucous membrane

32. LARYNGEAL INLET
• Above and in front: upper
margin of epiglottis
• Below and behind: inter-
arytenoid fold of mucous
membrane
• On each side: aryepiglottic fold

34. BOUNDARIES AND FEATURES
• Lateral wall: On each side of laryngeal inlet, presents piriform fossa –
mucous membrane covered depression
Boundaries of Piriform fossa
• Medially: Aryepiglottic fold
• Laterally: mucous membrane covering the medial surface of lamina
of thyroid cartilage and thyrohyoid membrane
• Above: It is separated from epiglottic vallecula by the pharyngo-
epiglottic fold (lateral glosso-epiglottic fold)

35. IMPORTANCE OF PIRIFORM FOSSA
1. More deep in ruminating animals and act as lateral food channels to
convey the bolus of food
2. Acts as catch point for foreign body
3. Sometimes, fossa is artificially deepened by smugglers

36. WALDEYER’S RING
• They are composed of rings of lymphoid tissue which encircles the
cephalic part of air and food passages, provide defensive mechanism:
1. Lingual tonsils -ventrally
2. Palatine tonsils - laterally
3. Tubal tonsils - laterally
4. Naso-pharyngeal tonsils - dorsally

38. STRUCTURE OF PHARYNX
• Wall of pharynx presents following coats from outside inside:
1. Areolar coat/Bucco-pharyngeal fascia
2. Muscular
3. Submucosa
4. Mucosa

39. AREOLAR TISSUE LAYER
• Known as Bucco-pharyngeal fascia
• Not well defined, attached above to base of skull
• Represents epimysium of pharyngeal muscles
• Covers outer surface of constrictor muscles of pharynx as a loose
membrane. It extends forwards over buccinator .

40. MUSCLES OF PHARYNX
• The muscles of the pharynx are organized into two groups based on
the orientation of muscle fibres.
• The constrictor muscles have fibres oriented in a circular direction
relative to the pharyngeal wall and
• The longitudinal muscles have fibres oriented vertically.

41. MUSCLES OF PHARYNX
1. Outer circular layer: 3 paired muscles
1. Superior constrictor
2. Middle constrictor
3. Inferior constrictor – Thyro-pharyngeus, Crico-pharyngeus
2. Inner longitudinal layer: 3 paired muscles
1. Stylopharyngeus
2. Palato-pharyngeus
3. Salpingo-pharyngeus

44. ACTIONS OF CONSTRICTOR MUSCLES
• All the constrictors contract reflexly during deglutition and induce a
wave of peristalsis which passes in caudal direction.
• Thyro-pharyngeus acts propulsive in nature
• Crico-pharyngeus acts as a sphincter, normally kept closed except
during deglutition.
• When the Thyro-pharyngeus contracts, the Crico-pharyngeus relaxes
and vice versa.

48. ACTIONS OF LONGITUDINAL MUSCLES
• They elevate the larynx and shorten the pharynx during swallowing
and at the same time, the palato-pharyngeus sphincter closes the
pharyngeal isthmus.

49. STRUCTURES PASSING BETWEEN CONSTRICTORS
Gap Structures passing
Through the sinus of Morgagni
(the interval between the base of
skull and superior constrictor)
Auditory tube, Levator veli palitini,
Ascending palatine artery, palatine
branch of ascending pharyngeal
artery
Between superior and middle
constrictor
Stylopharyngeus,
glossopharyngeal nerve
Between middle and inferior
constrictor
Internal laryngeal nerve, superior
laryngeal vessels
Below the inferior constrictor Recurrent laryngeal nerve, inferior
laryngeal vessels

51. SUBMUCOSA
• This is thickened in the upper
part to form the
pharyngo-basilar fascia which
closes the sinus of Morgagni and
is attached to base of skull.
MUCOUS MEMBRANE
• Naso-pharynx- ciliated columnar
epithelium
• Oro-pharyx and Larygo-pharynx :
non-keratinized stratified squamous
epithelium

52. NERVE SUPPLY - MOTOR
• Motor: All pharyngeal muscles are
supplied by cranial part of accessory
nerve via the pharyngeal plexus except
stylopharyngeus
• Inferior constrictor is supplied additionally
by recurrent laryngeal nerve and external
laryngeal nerve

53. NERVE SUPPLY - SENSORY
• Nasopharynx- by pharyngeal branch of pterygopalatine ganglion,
conveying fibers of the Maxillary nerve
• Oro-pharynx- Glossopharyngeal nerve
• Laryngo-pharynx- Internal laryngeal nerve

55. PHARYNGEAL PLEXUS
• Formed by
1. Pharyngeal branch of vagus carrying fibers from cranial part of
accessory nerve
2. Pharyngeal branch of glossopharyngeal nerve
3. A branch from superior cervical ganglion of sympathetic trunk
4. Sometime, a branch from external laryngeal nerve

56. PHARYNGEAL PLEXUS
• The plexus lies on Bucco-pharyngeal fascia which covers middle
constrictor.
• Vagal fibers – motor
• Glossopharyngeal fibers – sensory
• Sympathetic fibers - vasomotor

57. ARTERIAL SUPPLY
• Ascending pharyngeal artery
• Ascending palatine and tonsillar
branches of facial artery
• Greater palatine, pharyngeal
and pterygoid branches of
maxillary artery
• Dorsal lingual branches of
lingual artery

58. VENOUS DRAINAGE
• The veins accompany the
arteries, form plexus which
joins the pterygoid venous
plexus which finally drain
into Internal jugular vein

59. CLINICAL CORRELATION
• Dysphagia – difficulty in swallowing
• Odynophagia – painful deglutition
• Pharyngeal diverticulum – in neuromuscular incoordination, when
both parts contract simultaneously, intra-pharyngeal pressure rises,
mucus membrane bulges through dehiscence forming diverticulum.

60. CLINICAL CORRELATION
• Zenker’s diverticulum- outpouching in
posterior pharyngeal wall through Killan’s
triangle – point of least resistance, located
superior to cricopharyngeal and inferior to
thyro-pharyngeus parts of inferior constrictor.
• May present with dysphagia, rarely pain.

61. THANK YOU