anatomy

1. ANATOMY &
PHYSIOLOGY OF
PHARYNX

2. ANATOMY-PHARYNX
12-14 cm.long conical
fibromuscular tube extending
from base of skull to lower
border of cricoid cartilage.
 Width 3.5cm at base , & 1.5cm at
pharyngo-esophageal junction.

3. Structure of pharyngeal
wall
from within outwards :
 Mucous membrane.
 Pharyngeal aponeurosis
(pharyngobasilar fascia).
 Muscular coat.
 Buccopharyngeal fascia..

4. DIVISIONS OF PHARYNX:
1. Nasopharynx
2. Oropharynx
3. Hypo or laryngopharynx.

6. NASOPHARYNX
• Upper most part of pharynx.
• Extends from base of skull to the
soft palate or a horizontal plane
passing through hard palate.
• Epipharynx.

7. OROPHARYNX
• Extends from the plane of hard palate above to
the plane of hyoid bone below.

8. HYPO OR
LARYNGOPHARYNX
• Lowest part of the pharynx.
• Lies opposite 3rd,4th,5th& 6th cervical vertebrae
• Superiorly from the plane passing from the
body of hyoid bone to posterior pharyngeal
wall, to inferiorly the lower border of cricoid
cartilage.

11. SINUS OF MORGAGNI
 Space between the base of the skull & upper
free border of superior constrictor muscle.
 Following pass through it
 Eustachian tube
 Levator veli palatini
 Tensor veli palatini.
 Ascending palatine branch of facial

12. KILLIAN’S DEHISCENCE
 Between two parts of inferior constrictor muscle.
 Potential gap between thyropharyngeus(oblique)
& cricopharyngeal(transverse) muscle fibres.
 ‘ Gateway of Tears ’
 Pharyngeal pouch.

13. WALDEYER’S RING
Scattered through out the pharynx is its sub-
epithelial layer is the lymphoid tissue which is
aggregated at places to form masses
collectively called Waldeyer’s Ring
The masses are :
 Nasopharyngeal tonsil or the adenoids
 Palatine tonsils
 Lingual tonsils
 Tubal tonsils
 Lateral pharyngeal bands
 Nodules is posterior pharyngeal wall

14. NASOPHARYNX
• Upper most part of pharynx.
• Extends from base of skull to the
soft palate or a horizontal plane
passing through hard palate.
• Epipharynx.

15. ANATOMY:
• Roof – basisphenoid & basiocciput
• Anterior wall – Choanae, Septum, Turb & Meati
• Posterior wall – Arch of Atlas, Prevertebral
muscles & fascia
• Lateral wall – ET, Torus, R. Fossa, & Fold
• Floor – Soft pal., N P Isthmus

17. ADENOIDS ANATOMY
 Site – Roof & Post wall NPX
 Vertical ridges & clefts
 Sub epithelial collection of lymphoid tissue.
 Ciliated columnar epithelium
 No crypts & no capsule
 Increases in size up to 6yrs & then gradually
atrophies.
 Directly to Upper Jugular N. & Post. Triangle nodes
or through Retropharyngeal N., Parapharyngeal N.,

18. NASOPHARYNGEAL
BURSA
 Epithelial-lined median recess within adenoid
mass.
 Extends from pharyngeal mucosa to periosteum
of basiocciput.
 Represents attachment of notochord to
pharyngeal endoderm.
 Thornwald’s disease.

19. THORNWALD’S DISEASE
 This is an abscess that develops in
nasopharyngeal bursa. Infected bursa usually
presents with persistent postnasal discharge or
crusting.

20. RATHKE’S POUCH
 Represented by a dimple just above the adenoids.
 Reminiscent of the buccal mucosal invagination
to form the anterior lobe of pituitary.
 Craniopharyngioma.

21. TUBAL TONSIL
 Collection of subepithelial lymphoid tissue
situated at the tubal elevation.
 Part of waldeyer’s ring.
 If enlarged – can cause eustachian tube occlusion.

22. PASSAVANT’S RIDGE
Mucosal ridge raised by fibers of
palatopharyngeus muscle.
Encircles the posterior & lateral
wall of nasopharyngeal isthmus.
In deglutition & denasal speech –
soft palate contracts touches this
ridge

23. LYMPHATIC DRAINAGE
OF NASOPHARYNX
 Directly to Upper Jugular
Nodes.
 Posterior Triangle nodes
 Or Through Retropharyngeal
Nodes, & Parapharyngeal Nodes

24. FUNCTIONS OF NASOPHARYNX
 Acts as conduit for air.
 Through Eustachian tube ventilates middle ear.
 Acts as resonating chamber during voice
production.
 Elevating soft palate against posterior
pharyngeal wall in swallowing , vomiting,
gagging & speech
 Acts as a drainage channel for mucus.

25. OROPHARYNX
• Extends from the plane of hard palate above to
the plane of hyoid bone below.
• anatomically,
anterior wall,posterior wall & lateral wall.

26. OROPHARYNX SITE
 Posterior to the oral cavity -Oro
Pharyngeal Isthmus
 Inferior to the level of the soft
palate and
 Superior to the upper margin of the
epiglottis
 Sides by Palatoglossal Arches

27. OROPHARYNX- WALLS
 Lateral wall of the oro-pharynx presents on each side
the palatine tonsil which lodges in a triangular tonsillar
fossa.
 Boundaries of the tonsillar fossa
 Front : Palato-glossal arch containing the
corresponding muscle.
 Behind : Palato-pharyngeal arch containing the
corresponding muscle.
 Apex : Soft palate while both arches meet.
 Base : Dorsal surface of posterior third of tongue,
(vallecula, & folds)
 Floor : Superior constrictor and stylo-glossus
muscles covered internally by pharyngo-basilar
fascia.

29. OROPHARYNX MECHANISM
 The oro-pharyngeal isthmus in closed deglutition
 This is to prevent regurgitation of food from the
pharynx to the mouth.
 This is achieved by :
 Depression of the soft palate
 Elevation by back of tongue and movement
towards the midline of palatoglossal and
palatopharyngeal folds.
 This allows a person to breath while chewing or
manipulating material in oral cavity.

30. FUNCTIONS OF
OROPHARYNX:
As a conduit for passage of air &
food.
Helps in pharyngeal stage of
deglutition.
Provides local defence &
immunity Sentinels - Waldeyers
ring – Ig A, M, & D
Appreciation of taste.
Vocal tract for Sounds

31. HYPO OR
LARYNGOPHARYNX
• Lowest part of the pharynx.
• Lies opposite 3rd,4th,5th& 6th cervical vertebrae
• Superiorly from the plane passing from the
body of hyoid bone to posterior pharyngeal
wall, to inferiorly the lower border of cricoid
cartilage.

32. DED INTO THREE
REGIONS:
1.Pyriform sinus(fossa)
2.Post cricoid region
3.Posterior pharygeal wall

33. PYRIFORM SINUS(FOSSA)
 Lies on either sides of larynx & extends
from pharyngoepiglottic fold to upper end
of esophagus.
 Bounded laterally by thyrohyoid
membrane & thyroid cartilage and
medially by aryepiglottic fold ,
posterolateral surfaces of arytenoid &
cricoid cartilages.
 FBs, Ca
 Internal laryngeal nerve – pain, refd pain,
LA

34.  Post cricoid region : between upper &
lower borders of cricoid lamina.-
Plummer vinson, Ca
 Posterior pharygeal wall : extends from
the level of hyoid bone (floor of
vallecula) to the level of
cricoarytenoid joint.

35. FUNCTIONS OF
LARYNGOPHARYNX:
• common pathway for air & food.
• provides a vocal tract for
resonance of certain speech
sounds &
• helps in deglutition
• Killians- Pouch

38. WALDEYER’S RING
Scattered through out the pharynx is its sub-
epithelial layer is the lymphoid tissue which is
aggregated at places to form masses
collectively called Waldeyer’s Ring
The masses are :
 Nasopharyngeal tonsil or the adenoids
 Palatine tonsils
 Lingual tonsils
 Tubal tonsils
 Lateral pharyngeal bands
 Nodules is posterior pharyngeal wall

39. WALDEYERS RING

40. THE PALATINE TONSILS
 It is an ovoid mass of lymphoid tissues situated
is the lateral wall of the oropharynx in the
tonsillar fossa.
Each tonsil presents
 Two surfaces-Medial and lateral
Two poles-upper and lower

41. THE PALATINE TONSILS-Contd….
Upper pole :
Extends into the soft palate
Its medial surface covered by a semilunar
fold and encloses a potential space called
supratonsillar fossa.
Lower pole :
It is continuous with the tongue,
Tonsillo-lingual sulcus separates the tonsil
from the tongue.

42. THE PALATINE TONSILS-Contd….
Medial surface :
 Covered by non-keratinised
stratified squamous epithelium.
 The epithelium dips into the
substance by the tonsil in the
form of crypts.
 Crypts – 12 to 15 primary ,
secondary, debris
 One of the crypts, situated near
the upper pole is large and
deep and in called crypta
magna or intra-tonsillar cleft –
cause for peritonsillar abscess.

43. THE PALATINE TONSILS-Contd….
Lateral surface :
 Presents a well defined fibrous capsule.
 Between the capsule and bed of tonsil is the
loose areolar tissue.
 It is the site for collection of pus is peritonsillar
abscess.
 Plane of dissection in tonslllection

44. TONSILLAR BED INSIDE OUT
 Superior constrictor &
styloglossus muscle
 Glossopharyngeal Nerve, &
Styloid process
 Facial artery,
Submandibular salivary
gland,
 Digastric (post belly), Med
Pterygoid, Mand angle

46. HISTOLOGY OF TONSIL
 It is covered by stratified squamous epithelium
 Tonsil consists of numerous lymphatic follicles
which surround the tonsillar crypts.
 Each follicle presents a germinal centre
composed of lymphoblasts

47. ARTERIAL SUPPLY TO TONSIL
Tonsillar branch of –
Descending palatine of maxillary
Ascending pharyngeal
Ascending palatine of facial
Tonsillar br of facial - main
Dorsalis linguae of Lingual

48. VENOUS DRAINAGE OF TONSIL
 Veins drain into Para tonsillar vein
( Dennis brown vein)
 Then to common facial vein & pharyngeal
plexus

49. Lymphatic drainage :
 Drains into jugulo-digastric lymph node.
 Situated below and behind the angle of
mandible.
 It is considered as the principal lymph mode
of tonsil.
Nerve supply :
 Glossopharyngeal nerve.
 Lesser palatine branches of sphenopalatine
ganglion.

50. APPLIED ANATOMY
 Have a protective role, act as sentinals at
the portal of air and food passage.
 Tonsils may themselves get infected and
act as septic foci indicating surgical
removal of tonsils.
 Post tonsillectomy loss of taste sensation
can occur due to involvement of
glossopharyngeal nerve.
 Some times referred pain from the infected
tonsil may extend into middle ear.

52. RETROPHARYNGEAL
SPACE
Lies - behind the pharynx between the
buccopharyngeal
fascia covering pharyngeal constrictor
muscles and the prevertebral fascia
Extension - From the base of the skull to
bifurcation of
trachea.

53. PARA PHARYNGEAL SPACE
 It is Pyramidal in shape with its base at the base
of the skull and its apex at the hyoid bone.
 Relations:
Medial - Buccopharyngeal fascia
Posterior - Prevertebral fascia covering
prevertebral muscles and transverse
process of cervical vertebra
Lateral - Medial Pterygoid Muscle,
Mandible and deep surface of parotid
gland.

54. PARA PHARYNGEAL
SPACE
 Styloid process and muscles attached to it
divide the space into anterior and posterior
compartments
 Anterior Compartment :
Related to tonsillar fossa &
medial pterygoid fossa
laterally.
 Posterior Compartment :
Related to posterior part of
lateral
pharyngeal wall medially and