Pharynx is upper part of the aerodigestive tract. It has three parts nasopharynx, oropharynx and laryngopharynx. Pharynx plays an important part in respiration and swallowing. Swallowing is a very complex process. To swallow properly it is important to shut down the openings of nasopharynx, oral cavity and larynx and open the upper sphinctor of esophagus.

1. ANATOMY
OF
PHARYNX
BRIG DR ANWAR UL HAQ
ENT SPECIALIST

2. Conical fibromuscular
tube – upper part of the
air & food passages
Location:
Behind
Nasal cavity,
Oral cavity
Larynx
2
PHARYNX

3. Extend from the base of the
skull to the inferior border of
cricoid cartilage (anteriorly) &
the inferior border of C6
vertebra (posteriorly)
Dimensions:
12-14cm long
Width :
3.5 cm (at its base)
1.5 cm (pharyngo-
oesophageal junction –
narrowest part)
3

4. 4

5. 5

6. 6

7. 7

8. 8

9. 9

10. Superior
Base of the skull
• Part of body of
sphenoid
• Basilar part of
occipital bone
Anterior (Incomplete)
Nasal cavity Oral
cavity
Larynx
Posterior
Retropharyngeal
space (between the
buccopharyngeal &
prevertebral fascia)
4
Inferior
Continuous with oesophagus (at
level of C6 & lower border of
circoid cartilage

11. Superior
Base of the skull
• Part of body of
sphenoid
• Basilar part of
occipital bone
Anterior (Incomplete)
Nasal cavity Oral
cavity
Larynx
Posterior
Retropharyngeal
space (between the
buccopharyngeal &
prevertebral fascia)
4
Inferior
Continuous with oesophagus (at
level of C6 & lower border of
circoid cartilage

12. Superior
Base of the skull
• Part of body of
sphenoid
• Basilar part of
occipital bone
Anterior (Incomplete)
Nasal cavity Oral
cavity
Larynx
Posterior
Retropharyngeal
space (between the
buccopharyngeal &
prevertebral fascia)
4
Inferior
Continuous with oesophagus (at
level of C6 & lower border of
circoid cartilage

13. Structure of pharyngeal wall
PHARYNGEAL
APONEURESIS
(Pharyngobasilar fascia)
• Fibrous layer which lines
muscular coat
• Thick (base of skull) & thin (
inferiorly)
MUCOUS MEMBRANE
• Lines pharyngeal cavity &
continuous with mucous
membrane Eustachian
tubes, nasal cavities, mouth,
larynx & esophagus
• Stratified squamous except
nasopharynx (ciliated
columnar)
• Numerous mucous
glands
MUSCULAR
COAT
• External layer : superior,
middle,inferior constrictor muscle
• Internal layer :
stylopharyngeus,
salphingopharyngeus,
palatopharyngeus muscle
BUCCOPHARYNGEAL FASCIA
• Outer surface of constrictor muscle
&
buccinator muscle
• Upper border of superior
constrictor: Blend with
pharyngeal aponeurosis
1
3

14. External Layer Of Muscular Coat
Constrictor Muscles Of Pharynx
Generally:
Origins are situated
anteriorly
Fibers pass through anterior
& posterior wall of pharynx
All 3 muscles meet in
midline (in a fibrous raphe)
Arrangement:
Inferior constrictor overlaps
the middle constrictor
Middle constrictor overlaps
the superior constrictor
14

17. Superior Constrictor
Middle Constrictor
Inferior Constrictor

18. Superior constrictor muscle
Origin (from above to downwards)
• Pterygoid hamulus
• Pterygomandibular raphe
• Medial surface of mandible at posterior end of
mylohyoid line (near the attachment of
pterygomandibular raphe)
• Side of the posterior part of the tongue
18

19. Middle constrictor muscle
Origin
• Lower part of stylohyoid ligament
• Lesser cornu of hyoid bone
• Upper border of greater cornu of
hyoid bone
19

20. Inferior constrictor muscle
1. Thyropharnygeus
• Arise from thyroid
cartilage
–oblique line and inferior
tubercle
of thyroid cartilage
• A tendinous band that
crossed the cricothyroid
muscle & is attached
above to the inferior
tubercle of thyroid
cartilage
1. Cricopharyngeus
• Cricoid cartilage behind
the origin of cricothyroid
muscle
20

21. Internal layer of muscular coat [longitudinal muscles]
1. Stylopharyngeus
From styloid process,
• passes through the gap between superior
& middle constrictor
• Run downward to the inner surface of middle and
inferior constrictor
Stylopharyngeus
muscle
21

22. 2. Palatopharyngeus
• Descends from the sides of palate
• Runs longitudinally on the internal
aspect of 3 constrictors
Palatopharyngeus
muscle
22

23. 3. Salpingopharyngeus
• Descends from the auditory tube
• Merges with the palatopharyngeus
muscle
Salpingopharyngeus
muscle
23

24. 24

25. 25

26. Killian’s Dehiscence
Potential gap between thyropharyngeus with oblique fibers and
the cricopharyngeus with transverse fibers
“Gateway of tears”  Perforation can occur at this site during
oesophagoscopy
Site for herniation of pharyngeal mucosa in condition of pharyngeal
pouch
26

27. Waldeyer’s Ring *inner
• Several aggregations of lymphoid tissue
near the relation of oropharyngeal isthmus
• Composed of:
1. Right & left palatine tonsil (tonsil only)
2. Pharyngeal tonsil (posteriorly & above)
3. Tubal tonsil (laterally & above) –in fossa
Rosenmuller
4. Lingual tonsil (posterior part of the
dorsum of the tongue)
27

28. Pharyngeal Spaces
1. Retropharyngeal space
• Situated behind the pharynx & extending
from the base of skull to the bifurcation
of trachea
• Divided into 2 lateral compartments [spaces
of Gillette]
by a fibrous raphe
• Has retropharyngeal nodes –disappear at
3-4
years
• Infection can pass down behind the
oesophagus into
the mediastinum
28

29. 2. Parapharyngeal space
• Situated on the side of pharynx
• Contains carotid vessels, jugular vein,
last four cranial nerves & cervical
sympathetic chain
29

31. Parts of
pharynx
Laryngopharynx
• Plane of hyoid bone  lower
border of cricoid cartilage
2
0
Nasopharynx
• Base of skull  nasopharyngeal
isthmus
Oropharynx
• Nasopharyngeal isthmus  plane
of hyoid
bone

32. Parts of pharynx
1. Nasopharynx
Floor
• Soft palate anteriorly &
is deficient posteriorly
• Oropharynx via
nasopharyngeal
isthmus
Anterior
Nasal cavity via posterior
nasal apertures (choanae)
Lateral
Pharyngeal openings of the eustachian tube
In contact with anterior part of middle ear cavity
(opens at the level of inferior nasal conchae)
Roof
Basisphenoid & Basiocciput
Posterior
Prevertebral
muscles & fascia
2
1
• Uppermost part of
pharynx
(epipharynx)
• Lies behind the
nasal cavity
• Base of skull  Soft
palate/Level of the
horizontal plane
passing thru the
hard palate
• Lined by
respiratory
epithelium
(pseudostratified
ciliated columnar
epithelium)
• Rigid and non-
collapsible wall

33. Pharyngeal/ Nasopharyngeal
Tonsil/ Adenoids
Sub-epithelial collection of lymphoid
tissue at the junction of roof and
posterior wall of nasopharynx –
increases in size up to 6 years
& gradually atrophies.
Tubal tonsil
Collection of sub-epithelial
lymphoid tissue situated at the
tubal elevation.
Rathke’s pouch
Dimple above adenoids reminiscent of
buccal mucosal invagination, to form
anterior lobe of pituitary.
(*craniopharyngioma may arise from it)
Nasopharyngeal Bursa
• Epithelial lined median recess within adenoid
mass & extends from pharyngeal mucosa to
the periosteum of the basiocciput
• Attachment of notochord to the pharyngeal
endoderm24

34. Sinus of Morgagni
• Space between skull and
upper free border of superior
constrictor muscle.
• Structures passing through this
gap:
 Levator veli palatini
 Ascending palatine artery
 Tensor veli palatini
 Eustachian tube
Passavant’s Ridge
• Mucosal ridge raised by
fibres of
palatopharyngeus
• Encircles posterior and lateral
walls of
nasopharyngeal isthmus
• Soft palate, during its contraction
makes firm contact with this
ridge to cut off nasopharynx25

35. Lymphatic drainage
• Upper deep cervical nodes through:
 Retropharyngeal nodes
 Parapharyngeal nodes
• Spinal accessory chain of nodes in the posterior
triangle of the neck
Functions
1. Acts as a conduit for air;
nose and larynx.
2. Ventilates middle ear
through eustachian tube
and equalises air pressure
on both sides of TM.
3. Cuts off nasopharynx
from oropharynx with
the help of
Passavant’s ridge.
4. Acts as a resonating
chamber for voice
production26

36. 2. Oropharynx
Middle part of the pharynx behind oral cavity Communicates with:
•Nasopharynx
through nasopharyngeal (pharyngeal)
isthmus
•Oral cavity through the
oropharyngeal isthmus (isthmus of fauces)
•Laryngopharynx
at the level of upper border of epiglottis
2
7

37. 2. OropharynxMiddle part of
the pharynx
behind oral
cavity
Communicates
with:
• Nasopharynx
through
nasopharyng
eal
(pharyngeal)
isthmus
• Oral cavity
through the
oropharyngeal
isthmus
(isthmus of
fauces)
• Laryngopharyn
x at the level
of upper
Lateral wall -Anterior pillar
Palatoglossal arch Lateral wall -
Posterior pillar
Palatopharyngeal
arch
Posterior wall
Retropharyngeal space
Opposite to C2 and upper C3
vertebrae
Anterior wall
• Deficient above (communicates
with oral cavity)
• Below:
1. Base of the tongue –posterior
to circumvallate papilla
2. Lingual tonsil
3. Valleculae –cup shaped
depressions lying between the
base of the tongue & anterior
surface of epiglottis
2
7
“Isthmus of fauces = limit between the mouth cavity proper with
the pharynx marked by constricted aperture 

38. Anterior wall of oropharynx
38
• Deficient above
(communicates with oral
cavity)
• Below:
1. Base of the tongue –
posterior to circumvallate
papilla
2. Lingual tonsil
3. Valleculae –cup shaped
depressions lying between
the base of the tongue &
anterior surface of epiglottis

39. 39

40. Lateral wall of oropharynx
Pharyngeal wall
• Forms the lateral boundaries
of tonsillar fossa
• Composed of (from within
to outward):
1. Pharyngobasilar fascia
2. Superior constrictor &
palatopharyngeus
muscles
3. Buccopharyngeal fascia
4. Styloglossus muscle &
glossopharyngeal nerve
(lower part)
40

41. Tonsillar fossa
A triangular depression b/w
the anterior and the
posterior pillars,
contain palatine tonsils
41

42. Lymphatic drainage
• Upper jugular chain: jugulo-digastric nodes (tonsillar)
• Soft palate, lateral & posterior pharyngeal walls & base of the tongue
Retropharyngeal and parapharyngeal nodes  jugulo-digastric & posterior
cervical group
Functions
1. Conduit passage for air and food
2. Helps in pharyngeal phase of
deglutition
3. Forms part of vocal tract for speech
sounds
4. Helps in appreciation of taste (taste
buds)
5. Provide local immunity and defense
against harmful intruders
42

43. 3. Laryngopharynx
(Hypopharynx)
• Lowest part
• Situated behind the larynx
• Extend from upper border of
epiglottis to lower border of cricoid
cartilage
Mucosa membrane covering
the lamina of cricoid cartilage
43
Anterior (Post-cricoid region)
• Laryngeal inlet
• Posterior surface of cricoid and arytenoid cartilage
*common site for carcinoma in females with Plummer
Vinson syndrome

44. 3
4
Lateral wall
[Piriform fossa]
• On each side of laryngeal inlet
• Pharyngoepiglottic fold  upper end
of oesophagus
• Boundaries:
 Medially: aryepiglottic fold,
posterolateral surfaces of
aryteniud & circoid
cartilages
 Laterally: thyroid cartilage &
thyrohyoid membrane
 Covered by mucous membrane.
Beneath the membrane is
internal laryngeal nerve
• Smuggler’s fossa -Foreign bodies
may get lodged here
• Removal of foreign body from the
piriform fossa may damage the nerve
anesthesia to the supraglottic part
Posterior
• Level of hyoid bone
to the level of
cricoarytenoid joint

45. Lymphatic drainage
• Pyriform sinus  upper jugular chain
• Rich lymphatics  high frequency of nodal
metastasis in carcinoma of this region
• Post cricoid  parapharyngeal LN
/ nodes of supraclavicular and
paratracheal chain
• Post wall parapharyngeal LN or lateral
pharyngeal LN
 deep cervical LN
Function
s1. Common pathway for air and
food
2. Help in deglutition
3. Provides a vocal tract for
resonance of
certain speech sounds
4. Co-ordination between the
contraction of pharyngeal ms
and relaxation of
cricopharyngeal sphincter at
the upper end of oesophagus
35

46. Autonomic innervation
Parasympathetic (secretomotor)
1.Greater petrosal nerve (branch of
facial nerve)
2.Lesser palatine branches of
pterygopalatine ganglion
Sensory nnervation
Afferent fibers travel through:
1.Glossopharyngeal nerve (mostly)
2.Vagus nerve (partly)
3.Maxillary nerve through pterygopalatine ganglion
(nasopharynx
only)
4.Lesser palatine and glossopharyngeal nerve (soft
palate & tonsil)
Motor innervation
• All muscles of pharynx are supplied by the cranial accesory nerve through
branches of
vagus except stylopharyngeus muscle[ pharyngeal branches of glossopharyngeal
nerve]
• Inferior constrictor muscle has additional supply from the external and recurrent
laryngeal nerves
3
6

47. 3
6
Generally, all the nerves supplying the pharynx form a plexus (pharyngeal plexus) which
chiefly lies on the middle constrictor muscle:
1.Pharyngeal branch of vagus carrying cranial accesory nerve fibers
2.Pharyngeal branch of glossopharyngeal nerve
3.Pharyngeal branch of the superior sympathetic ganglion
Fibers from pharyngeal plexus also supplies the muscles of soft palate except tensor veli
palatini (by Mandibular nerve)

49. BARIUM
SWALLOW