The document discusses the anatomy of the pharynx. It can be summarized as follows: 1. The pharynx is a musculofascial tube that connects the oral and nasal cavities to the larynx and esophagus. It is divided into three parts - nasopharynx, oropharynx, and laryngopharynx. 2. The walls of the pharynx contain both longitudinal and circular muscles. It is lined by mucosa and surrounded by fascia. There are also potential spaces near the pharynx where abscesses can form. 3. The nasopharynx is the uppermost part behind the nose. It contains the eustachian

1. ANATOMY OF PHARYNX
Dr Harjitpal Singh
Assistant Professor(ENT),
Dr RKGMC, Hamirpur

2. PHARYNX
◆It is a musculo fascial half-cylinder that links the oral and
nasal cavities in the head to the larynx and esophagus
in the neck. It is 12–14 cm long.
◆It is attached above to the base of skull and continuous
below, approximately at the level of the sixth cervical
vertebra, with the top of esophagus.
◆The width of pharynx is 3.5 cm at its base and this narrows
to 1.5 cm at pharyngo-oesophageal junction, which is the
narrowest part of digestive tract apart from the appendix.
◆The pharyngeal cavity is a common pathway for ‘air ’and
‘food’. (common passages of respiratory systems and
digestive systems)

4. BOUNDARIES
a. Superiorly-Baseof skullincluding posterior
part of body of sphenoid and the basilar
part of the occipital bone.
b. Inferiorly-pharynx continues with oesophagus
at the level of 6th cervical vertebra/ lower
border of cricoid cartilage.
c. Posteriorly-Prevertebralfasciaseparating it from
cervical spine
d. Anteriorly-Communication with Nasal cavity,
Oralcavity, andLarynx.

5. BOUNDARIES
e.On eachside-
i) It is attached to the
Medial pterygoid plate
Pterygo mandibular raphe
Mandible
Tongue
Hyoid bone
Thyroid and cricoid cartilages
ii) Communication with middle ear via eustachiantube
iii) Styloid process and muscles attached to it
iv) Common, Internal and External CarotidArtery

6. DIVISIONS OF PHARYNX

7. DIVISIONS OF PHARYNX

8. DIVISIONS OF PHARYNX
1. NASOPHARYNX/ EPIPHARYNX
From the base of skull above to the level of
soft palate/ palatal sphincter (C2 level).
2. OROPHARYNX
From palatal sphincter to the level of tip of
epiglottis (C4 level).
3. LARYNGOPHARYNX/ HYPOPHARYNX
From tip of epiglottis to the lower border of
cricoid cartilage (lower border of C6).

9. STRUCTURE OF PHARYNX
From within outwards it consists of four layers:
1. Mucous membrane-It is ciliated columnar in the
nasopharynx and stratified squamous
elsewhere.
2. Pharyngealaponeurosis/Pharyngobasilar fascia-it is a
fibrous layer lining the muscular coat.
3. Muscularcoat-consist of-
a. OuterCircularLayerconsist of 3 muscles-
>Superiorconstrictor>Middle constrictor>Inferior constrictor
b. InnerLongitudinalLayerconsist of 3 muscles-
>Stylopharyngeus >Salpingopharyngeus >Palatopharyngeus
4. Buccopharyngealfascia-coversthe outer surface of
constrictor muscles and in the upper part, prolonged
forwards to cover the buccinator muscles.

10. STRUCTURE OF PHARYNX
Base of
skull
Eustachian
tube
a. Mucousmembrane
Sub mucosa
b. Pharyngobasilar fascia
c. Muscular coat
d. Buccopharyngeal fascia
c. Inferior
Constrictor
a. Superior
Constrictor
Venous Plexus
b. Middle Constrictor
Sinus of
Morgag
ni

11. PHARYNGEAL WALL

12. PHARYNGEAL WALL
Muscle
Posterior
Attachment
Anterior
Attachment Innervation Function
Superior
Constrictor
Pharyngea
l raphe
Pterygomandibular raphe and adjent bone
on the mandibular and pterygoid hamulus
Vagus Nerve Constriction
of pharynx
★Constrictor muscles*:
Middle
Constrictor
Pharyngea
l raphe
Upper margin of greaterbhorn of hyoid bone
and adjent margins of lesser horn and
stylohyoid ligament
Vagus Nerve Constriction
of pharynx
Inferior
Constrictor
Pharyngea
l raphe
Cricoid cartilage,oblique line of thyroid
crtilage, and a ligament that spans between
these attachments and crosses the
crocothyroid muscle
Vagus Nerve Constriction
of pharynx

13. 26

14. PHARYNGEAL WALL
★Longitudinal muscles:
Muscle Origin Insertion Innervation Function
Stylopharyngeus Middle side of base
of styloid process
Pharyngeal wall Glossopharyngea
l nerve [Ⅸ]
Elevation of the
pharynx
Salpingppharyngeus Inferior aspect of pharyn-
geal end of pharyngo-
tympanic tube
Pharyngeal wall
Vagus nerve [Ⅹ]
Elevation of
pharynx
Palatopharyngeus Upper surface of
palatine aponeurosis
Pharyngeal wall Vagus nerve [Ⅹ] Elevation of phary-
nx, and closure of
the oropharyngeal
isthmus

15. 15

16. FASCIA
• The pharyngeal fascia is separated into two
layers:
Buccopharyngeal Fascia: a thin layer, coats the
outside of the muscular part of the wall.
Pharyngobasilar Fascia: a much thicker layer,
lines the inner surface

17. PHARYNGEAL SPACES
There are two potential spaces in relation to the
pharynx where abscesses can form.
1. Retropharyngeal space, situated behind the
pharynx.
2. Parapharyngeal space, situated on the side of
pharynx.

18. RETROPHARYNGEAL SPACE
• Between the buccopharyngeal fascia and prevertebral fascia,
which extends from skull base to the upper part of
posterior mediastinum (T1,T2), the bifurcation of
trachea.
• Anteriorly by the posterior pharyngeal wall and
buccopharyngeal fascia.
• Posteriorly by the cervical vertebra their muscles and fascia.
• One on each side, and separated from parapharyngeal space.
• It contains retropharyngeal lymph nodes and connective
tissue.

19. RETROPHARYNGEAL SPACE

20. PARAPHARYNGEAL SPACE
• Situated on the side of pharynx.
• It is an inverted cone-shaped potential space
that extends from the hyoid bone to the
base of the skull.
• It’s occupied by the
carotid vessels,
Internal jugular vein,
Deep cervical lymph nodes,
The last four cranial nerves and
Cervical sympathetic trunk.

21. KILLIAN’S DEHISCENCE
• Inferior constrictor muscle has two parts:
Thyropharyngeus with oblique fibres and
Cricopharyngeus with transverse fibres.
• Between these two parts exists a potential gap
called Killian’s dehiscence.
• It is also called “gateway of tears” as perforation
can occur at this site during oesophagoscopy.
• This is also the site for herniation of pharyngeal
mucosa in cases of pharyngeal pouch-
zenker’s diverticulum.

22. KILLIAN’S DEHISCENCE

23. WALDEYER’S RING
• Scattered throughout the pharynx in its subepithelial layer
is the lymphoid tissue which is aggregated at places to
form masses, collectively called Waldeyer’s ring.
• It has no afferents and efferents drain into cervical lymph
nodes.
• The masses are:
1. Nasopharyngeal tonsil or the adenoids
2. Palatine tonsils or simply the tonsils
3. Lingual tonsil
4. Tubal tonsils (in fossa of Rosenmüller)
5. Lateral pharyngeal bands
6. Nodules (in posterior pharyngeal wall).

24. WALDEYER’S RING

25. LYMPHATIC DRAINAGE
• Nasopharyngeal tonsil and some drainage
from tubal tonsil is to Retropharyngeal
nodes
• Oropharynx- Into Upper Jugular chain
particularly Jugulodigastric (tonsillar)
node.
• Soft palate, Lateral and Posterior pharyngeal
walls and base of tongue- into
retropharyngeal and parapharyngeal
nodes.

26. LYMPHATIC DRAINAGE

27. BLOOD SUPPLY OF PHARYNX
• Ascending pharyngeal branch of external carotid
• Ascending palatine branch of facial (branch of
external carotid)
• Greater palatine branch of maxillary.
• Venous drainage through plexus which drains to:
superiorly : pterygoid plexus in the
infratemporal fossa.
inferiorly : the facial and internal jugular
veins

28. NERVE SUPPLY OF PHARYNX
Nerve supply is by pharyngeal plexus of nerves,
which is formed by:
• Branch of vagus (X nerve): Motor supply
• Branches of glossopharyngeal (IX nerve):
Sensory supply
• Sympathetic plexus.

29. FUNCTIONS OF PHARYNX
• Pharynx helps to provide immunity and formation
of antibodies
• It protects the lower respiratory tract
• It forms plasma cells and lymphocytes
• Acts as a warning to the body against infectious
agents in air and food.

30. DIVISIONS OF PHARYNX

31. NASOPHARYNX (EPIPHARYNX)
• Nasopharynx is the uppermost part of the
pharynx and therefore, also called epipharynx.
• It is also called third chamber of nose, which lies
behind the nose and above the soft palate.
• Dimensions of nasopharynx are: 4 cm (height) × 4
cm (width) × 3 cm (length).
• Roof and posterior wall form a continuous sloping
surface, which is formed mainly by the basilar
part of occipital bone and to some extent, by
body of sphenoid and arch of altas vertebra

32. NASOPHARYNX (EPIPHARYNX)
• Floor is formed by the soft palate anteriorly but
is deficient posteriorly. It is through this
space, the nasopharyngeal isthmus, that the
nasopharynx communicates with the
oropharynx.
• Anterior wall is formed by posterior nasal
apertures or choanae, separated from each
other by the posterior border of the nasal
septum. Posterior ends of nasal turbinates
and meatuses are seen in this wall.

33. NASOPHARYNX (EPIPHARYNX)
• Lateral wall has the eustachian tube opening, 1
to 1.25 cm (equidistant from all walls), behind
and little below the posterior end of inferior
turbinate.
• The opening is triangular in shape, bounded
above and behind by tubal cartilage.
• Two folds of mucous membrane—
salpingopharyngeal and salpingopalatine
stretch from the opening of eustachian tube
to the walls of pharynx and palate.

34. NASOPHARYNX (EPIPHARYNX)
• Torus tubarius is a mucosal elevation in the
lateral aspect of the nasopharynx,
formed by the underlying pharyngeal
end of the cartilaginous portion of the
Eustachian tube.
• The opening of the Eustachian tube is
anterior to the torus tobarius.
• Above and behind the tubal elevation is a
recess called fossa of Rosenmüller, which is
the commonest site for origin of carcinoma.

35. FOSSA OF ROSENMÜLLER

36. NASOPHARYNX (EPIPHARYNX)
• Rathke’s pouch is seen as a dimple in the
roof of nasopharynx.
• It is reminiscent of the buccal mucosal
invagination, to form the anterior lobe of
pituitary.
• A craniopharyngioma may arise from it.

37. RATHKE’S POUCH

38. NASOPHARYNX (EPIPHARYNX)
• Sinus of Morgagni: It is an interval between upper
border of superior constrictor and base of skull
and many structures pass upward from the pharynx.
Structures passing through this gap-
-Levator veli palatini
-Ascending palatine artery
-Tensor veli palatini
-Eustachian tube
• Passavant ridge is an elevation formed by fibers of
superior constrictor and palatopharyngeus, which
helps in closing the nasopharynx from oropharynx
with the posterior border of soft palate. It encircles
the posterior and lateral walls of nasopharyngeal
isthmus

39. NASOPHARYNGEAL TONSIL (ADENOIDS)
• It is a subepithelial collection of lymphoid tissue at
the junction of roof and posterior wall of
nasopharynx.
• It causes the overlying mucous membrane to be
thrown into radiating folds.
• It increases in size up to the age of 6 years and then
gradually atrophies by age of 11-12 years.
• No feeding blood vessel, supplied by adjacent plexus
only.
• It has no capsule.

40. NASOPHARYNGEAL BURSA
• It is an epithelial-lined median recess found
within the adenoid mass.
• It extends from pharyngeal mucosa to the
periosteum of the basiocciput.
• It represents the attachment of notochord to the
pharyngeal endoderm during embryonic life.
• When infected, it may be the cause of persistent
postnasal discharge or crusting.
• Sometimes an abscess can form in the bursa
(Thornwaldt’s disease).

41. FUNCTIONS OF NASOPHARYNX
1. Acts as a conduit for air, which has been warmed, humidified
in the nose, towards its passage to the larynx and trachea.
2. Through the eustachian tube, it ventilates the middle ear and
equalizes air pressure on both sides of tympanic
membrane.
3. Elevation of the soft palate against posterior pharyngeal wall
and the Passavant’s ridge helps to cut off nasopharynx
from oropharynx. This function is important during
swallowing, vomiting, gagging and speech.
4. Acts as a resonating chamber during voice production. Voice
disorders are seen in nasopharyngeal obstruction and
velopharyngeal incompetence
5. Acts as a drainage channel for the mucus secreted by nasal
and nasopharyngeal glands.

42. OROPHARYNX

43. OROPHARYNX

44. OROPHARYNX

45. OROPHARYNX
Anterior wall:
• upper part- deficient, communicates with oral cavity
through Oropharyngeal isthmus/ Isthmus of Fauces.
• lower part - Base of tongue
- Lingual tonsils
- Valleculae
• Oropharyngeal isthmus: It is bounded by following
structures:
i. Above: Soft palate
ii. Inferior: Dorsal surface of tongue
iii. Lateral: On either side, by palatoglossal arch (anterior
tonsillar pillar)

46. OROPHARYNX
• Base of tongue: It lies posterior to circumvallate papillae
and insertion of palatoglossal muscle.
• Lingual tonsils: They are situated in the base of tongue.
• Valleculae: These cup-shaped spaces, one on each side, lie
between the base of tongue and anterior surface of
epiglottis.
• The median glossoepiglottic fold separates the two
valleculae.
• Laterally they are bounded by the pharyngoepiglottic fold
that is the upper limit of pyriform sinus of
laryngopharynx.

47. OROPHARYNX
• Posterior wall:
Body of second cervical and upper part of 3rd cervical
vertebra.
• Lateral wall:
- Palatine/Faucial tonsil
- Anterior pillar (Palatoglossus muscle)
- Posterior pillar(Palatopharyngeus muscle)
Both anterior and posterior pillars diverge from the soft
palate and enclose a triangular depression called tonsillar
fossa in which is situated the palatine tonsil

48. OROPHARYNX
• Superior:
Anteriorly soft palate makes the roof of
oropharynx.
Posteriorly it communicates with
nasopharynx through nasopharyngeal
isthmus at the plane of hard palate
and atlas vertebra.
• Inferior:
It communicates with laryngopharynx at
the plane of upper border of epiglottis
and the pharyngoepiglottic folds and
third cervical vertebra.

49. OROPHARYNX
Lymphatic Drainage:
• Upper jugular chain particularly the
jugulodigastric (tonsillar) node. „
• The soft palate, lateral and posterior pharyngeal
walls and the base of tongue also drain into
retropharyngeal and parapharyngeal nodes
and from there to the jugulodigastric and
posterior cervical group.
• The base of tongue may drain bilaterally

50. OROPHARYNX
Functions of Oropharynx:
• „
A common conduit for the passage of both air
and food.
• Oropharyngeal phase of deglutition.
• Vocal tract for certain speech sounds.
• Taste: The base of tongue, soft palate, anterior
pillars and posterior pharyngeal wall contain
taste buds. „
• Local defence and immunity.

51. PALATINE (FAUCIAL) TONSILS
• These are two masses of lymphoid tissue situated in the lateral
wall of oropharynx.
• Each tonsil is placed between palatoglossal (anterior pillar) and
palatopharyngeal fold (posterior pillar).
• Its medial surface is free and projects into the pharynx.
• Inferiorly, it extends into dorsum of tongue.
• Superiorly, it invades the soft palate.
• Plica triangularis is a free fold of mucous membrane extending
from palatoglossal arch to the anteroinferior part of tonsil.
• Upper part of tonsil contains a deep cleft called crypta magna
or intratonsillar cleft.
• Medial surface presents 12 to 15 orifices termed tonsillar crypts
or pits, which extend into the whole substance of tonsil,
branching inside the tonsil. These help in increasing the
surface area.

52. PALATINE (FAUCIAL) TONSILS
• Lateral surface is covered by fibrous capsule separated
from muscular wall formed by superior constrictor
with styloglossus muscle on its lateral side.
• At antero inferior part, the capsule is firmly attached in the
side of tongue.
• Tonsillar branch of facial artery with two veins enters the
tonsil at this point.
• Paratonsillar veins descend from the soft palate onto the
lateral aspect of capsule of tonsil and it is this vessel,
which is responsible for massive bleeding, if injured
during operation.
• Internal carotid artery lies 2.5 cm behind and lateral to the
tonsil.

53. PALATINE (FAUCIAL) TONSILS
• The tonsillolingual sulcus, which separates the tonsil
from tongue, is a common site for carcinoma.
• Supratonsillar fossa: The medial surface of tonsillar
upper pole has a semi-lunar fold, which extends
between anterior and posterior pillars. This pole
encloses a potential space called supratonsillar
fossa.
• Anterior tonsillar space: At the lower pole, which is
attached to the tongue, a triangular fold of
mucous membrane extends from anterior pillar
to the anteroinferior part of tonsil and encloses a
space called anterior tonsillar space.

54. PALATINE (FAUCIAL) TONSILS
Tonsillar Crypts:
• The nonkeratinizing stratified squamous epithelium on medial
surface of tonsil dips into the tonsillar mass and forms
crypts (12–15).
• Openings of crypts can be seen on the medial surface of the
tonsil. „
• Crypta magna or intratonsillar cleft: It is situated near the upper
part of tonsil. It is very large and deep and represents the
ventral part of second pharyngeal pouch.
• Secondary crypts: They arise from the main crypts within the
substance of tonsil. „
• Content: Crypts may be filled with cheesy material, which
consists of epithelial cells, bacteria and food debris and can
be expressed out with pressure over the anterior tonsillar
pillar.

55. PALATINE (FAUCIAL) TONSILS
Capsule:
• Lateral surface of tonsil is covered by a well-
defined fibrous capsule, which is separated
from the bed of tonsil by loose areolar tissue
that allows easy dissection in this plane during
tonsillectomy.
• In this same plane occurs the peritonsillar
abscess.
• Some fibers of palatoglossus and
palatopharyngeus muscles are attached to
tonsillar capsule.

56. PALATINE (FAUCIAL) TONSILS
Blood Supply:
• Arterial supply: The main artery of tonsil is
tonsillar branch of facial artery, which arises
from external carotid artery.
• The other vessels, which supply the tonsil include:
-Ascending pharyngeal artery from external carotid.
-Ascending palatine, a branch of facial artery.
-Dorsal lingual branch of lingual artery.
-Descending palatine branch of maxillary artery.

57. PALATINE (FAUCIAL) TONSILS
Blood Supply:
• The ascending pharyngeal, facial, lingual and maxillary
arteries are all branches of external carotid artery
that may need to be ligated in cases of refractory
bleeding after tonsillectomy.
• Venous drainage: Veins from the tonsils drain into
paratonsillar veins, which are present on lateral
surface of tonsil and drain into the common facial
vein and pharyngeal venous plexus.

58. BLOOD SUPPLY OF TONSIL

59. PALATINE (FAUCIAL) TONSILS
Nerve Supply:
• Lesser palatine branches from sphenopalatine
ganglion of maxillary division of trigeminal
nerve (CN V2). „
• Glossopharyngeal nerve (CN IX).

60. BED OF TONSIL

61. BED OF TONSIL
• The pharyngobasilar fascia, superior constrictor,
buccopharyngeal fascia, glossopharyngeal nerve
and styloglossus muscle form the bed of tonsil.
• Lateral to the superior constrictor muscles lies facial
artery, submandibular salivary gland, posterior
belly of digastric muscle, medial pterygoid muscle
and the angle of mandible.
• Styloid process: The styloid process when enlarged
may be palpated intraorally in the lower part of
tonsillar fossa. The glossopharyngeal nerve and
styloid process can be approached through the
tonsil bed after tonsillectomy.

62. HYPOPHARYNX
• Hypopharynx extends from the tip of epiglottis or
plane of hyoid bone to the lower border of
cricoid cartilage, from 3rd to 6th cervical
vertebrae.
• Clinically, it is subdivided into three regions:
Pyriform sinus,
Post cricoid region and
Posterior pharyngeal wall.

63. HYPOPHARYNX

64. HYPOPHARYNX
• Inferior: It becomes continuous with esophagus at
the level of lower border of cricoid cartilage and
6th cervical vertebra.
• Anterior: It communicates with larynx through the
laryngeal inlet, which is bounded by the
epiglottis, aryepiglottic folds and arytenoids.
• Inlet of larynx:
i. Posterior surface of arytenoid cartilage
ii. Posterior aspect of cricoid cartilage.
• Pyriform sinus lies on each side of laryngeal orifice.

65. HYPOPHARYNX
Pyriform sinus (Fossa):
• Each pyriform fossa, which lies on either side of the larynx,
forms the lateral channel for food.
• Foreign bodies may lodge in the pyriform fossa.
• Boundaries:
Lateral: Thyrohyoid membrane and the thyroid
cartilage.
Medial: Aryepiglottic fold, posterolateral surface
of arytenoid and cricoid cartilages.
Superior: Pharyngoepiglottic fold separates it
from vallecula.
Inferior: It opens into the esophagus at the level
of lower border of cricoid cartilage.

66. HYPOPHARYNX
Pyriform sinus (Fossa):
• Internal laryngeal nerve runs submucosally in the
lateral wall of the sinus and thus is easily
accessible for local anaesthesia.
• It is also through this nerve that pain is referred
to the ear in carcinoma of the pyriform sinus.
• It is most richly supplied by lymphatics, which
come out of thyrohyoid membrane to end in
upper deep cervical group of lymph nodes.

67. HYPOPHARYNX
Post cricoid region:
• This anterior wall of laryngopharynx
(pharyngoesophageal junction) extends
between the level of arytenoids and lower
border of cricoid lamina.
• Post cricoid region is a common site for
carcinoma, which usually develops from
Plummer-Vinson syndrome especially in
females.
• The sensory supply is the internal laryngeal nerve,
a branch of the superior laryngeal nerve„
.

68. HYPOPHARYNX
Post cricoid region:
• A rich venous plexus in this region drains into
superior laryngeal veins.
• It is more prominent in infants and engorges
during crying, known as the "postcricoid
cushion" on laryngoscopy, perhaps as
protection against emesis.

69. HYPOPHARYNX
Posterior pharyngeal wall:
• Posterior pharyngeal wall extends from hyoid
bone to the cricoarytenoid joint, between the
apices of pyriform fosse.

70. FUNCTIONS OF HYPOPHARYNX
• Common pathway for air and food. „
• Provides a vocal tract for resonance of certain speech
sounds. „
• Helps in deglutition.
• There is coordination between contraction of
pharyngeal muscles and relaxation of
cricopharyngeal sphincter at the upper end of
oesophagus.
• Lack of this coordination, i.e. failure of
cricopharyngeal sphincter to relax when
pharyngeal muscles are contracting causes
hypopharyngeal diverticulum.