Nasopharynx

1. ANATOMY OF NASOPHARYNX
AND EUSTACHIAN TUBE
Capt.Thet Paing Soe
PG-1st year (ORL-HNS)
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2. NASOPHARYNX
• Nasopharynx is the uppermost part of the pharynx and also called
epipharynx
• It lies behind the nasal cavity and extends from the base of the skull
to the free border of soft palate
• Nasopharynx connects the nasal cavity to the oropharynx and it
measures about 4 cm high , 4 cm wide and 2 cm deep
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4. BOUNDARIES OF NASOPHARYNX
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5. • Anterior wall
• Posterior separated from each other by posterior margin of nasal septum
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6. • Posterior wall
• In front of anterior arch of atlas of C1 vertebra covered by prevertebral
muscles and fascia
• Lateral wall
• Each wall has pharyngeal orifice of eustachian tube 1.25cm behind
posterior end of inferior turbinate.
• Roof
• Sloping edge formed by basisphenoid and basiocciput
• Floor
• Anterior 1/3 is formed by upper surface of soft palate , in deficit space
communicates with oropharynx by nasopharyngeal isthmus
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8. Contents of Nasopharynx
1. The eustachian tube opening
2. The tubal tonsil of tubal elevation ( torus tubarius )
3. The fossa of Rosenmuller
4. Sinus of Morgagni
5. The adenoids ( Nasopharyngeal tonsils )
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9. • The eustachian tube opening
• It’s located at the posterolateral wall , 1.25 cm behind the posterior
end of inferior turbinate
• The tubal tonsil of tubal elevation ( torus tubarius )
• It’s located superior and posteriorly to the opening of the eustachian
tube
• It is collection of subepithelial lymphoid tissue situated at the tubal
elevation
• It is continuous with adenoid tissue and forms a part of the
Waldeyer’s ring
• When enlarged due to infection , it causes eustachian tube occlusion
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11. • The fossa of Rosenmuller
• Fossa of Rosenmuller is located superior and posteriorly to the torus
tubarius and 2.5 cm depth in adult
• Its apex lies near the edge of carotid canal opening
• It opens into nasopharynx at a pont below foramen lacerum
• It is the commonest site for the origin of carcinoma nasopharynx
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12. • Bounded by
• Anteriorly – Eustachian tube and levator palatine muscle
• Posteriorly – Pharyngeal wall mucosa overlying pharyngobasilar fossa
and retropharyngeal space
• Medially – Nasopharyngeal cavity
• Laterally - Tensor palatine , mandibular nerve and prestyloid
compartment of parapharyngeal space
• Superiorly – Foramen lacerum and floor of carotid canal
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14. • Sinus of Morgagni
• It is a space between the base of the skull and upper free border of
superior constrictor muscle
• Through it enters
• The Eustachian tube
• The levator veli palatini
• Tensor veli palatini
• Ascending palatine artery – branch of facial artery
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16. • The adenoids ( Nasopharyngeal tonsils )
• It is a subepithelial collection of lymphoid tissue at the junction of
roof and posterior wall of nasopharynx and 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
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17. • Nasopharyngeal isthmus and Passavant’s Ridge
• It is a mucosal ridge raised by fibres of palatopharyngeus
• It encircles the posterior and lateral walls of nasopharyngeal
isthmus
• Soft palate , during its contraction make firm contact with this
ridge to cut off nasopharynx from the oropharynx during the
deglutition or speech
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19. • Lymphatic drainage
• Nasopharynx drain to upper deep cervical nodes either directly or
indirectly through nodes of Rouvier
• It also drains to spinal accessory nodes of posterior triangle and
may cross midline and drain into contralateral lymph nodes
• Epithelial lining of Nasopharynx
• Nasopharynx is lined by pseudostratified ciliated columnar
epithelium
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20. • Blood Supply
• Ascending pharyngeal artery
• Facial artery
• Ascending palatine artery
• Maxillary Artery
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22. • Nerve Supply
• Sensory
• Cranial V nerve ( proximal to eustachian tube )
• Cranial IX nerve ( posterior to eustachian tube )
• Motor
• Cranial XI nerve
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23. • Functions
• Conduct of air in its passage to larynx
• Protects airway during swallowing by elevation of soft palate
against posterior pharyngeal wall and Passavant’s Ridge
• Resonating Chamber for voice production
• Through the eustachian tube , it ventilates the middle ear and
equalizes air pressure on both sides of tympanic membrane
• Drainage channel for the mucus secreted by nasal and
nasopharyngeal glands
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24. • Applied Anatomy
• Nasopharyngeal carcinoma can spread to contralateral side due to
cross lymphatic drainage , to parapharyngeal space and all cranial
nerve if skull base is involved and middle ear through eustachian
tube
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25. Eustachian Tube
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26. Introduction
History
• Bartolomeo Eustachio was the first to exactly
describe the auditory tube in 1562.
• Antonio Valsalva suggested naming the auditory
tube after its discoverer as Eustachian tube.
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27. Embrology
• Develops from Tubo-tympanic recess, derived from endoderm of 1st
pharyngeal pouch.
• The distal portion of the pouch expands and forms middle ear cavity.
• Proximal portion forms the Eustachian tube.
• Cartilage and muscles develop from surrounding mesoderm.
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29. Anatomy
• 36mm long in adults.
• Directed anteriorly ,inferiorly & medially from anterior wall of middle
ear, forming angle of 45 degree with horizontal .
• Enters nasopharynx 1.25cm behind posterior end of inferior
turbinate.
• Channel is connecting tympanic cavity and nasopharynx.
• Lumen of ET is roughly triangular measuring 2-3mm vertically and 3-
4mm horizontally.
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31. Parts
• Lateral one third is bony.
• Medial two third is fibrocartilaginous.
• Junction between two parts is isthmus,
the narrowest part of Eustachian tube.
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32. Bony part
• 12 mm long
• Widest at tympanic
end
• Gradually narrows
towards isthmus
(2mm)
• Thin plate is separating
from tensor tympani
superiorly
• Plate of bone is
separating from
internal carotid
medially
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33. Cartilaginous part
• 24mm long
• Cartilage forms posteromedial wall and a small portion anterolaterally
• consists of medial + lateral laminae separated by elastin hinge.
• Fibrous tissue +Ostmann’s fat pad lie antero-laterally.
• It is in a groove between petrous temporal bone and greater wing of
sphenoid
• Nasopharyngeal opening is surrounded by tubal elevation above and
behind
• Fossa of Rosen Muller is lying behind this tubal elevation
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36. • Lining epithelium : Pseudo stratified ciliated columnar
• Arterial supply : ascending pharyngeal & middle meningeal arteries
• Venous drainage : pharyngeal & pterygoid venous plexus
• Lymphatic drainage : retropharyngeal node
Muscles attached to ET
• Levator veli palatini - runs inferior and parallel to the cartilaginous
part of the tube forms a bulk under the medial lamina, and during
contraction pushes it upward and medially thus assists in opening the
tube.
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37. • Tensor palate-The medial fibres of the tensor veli palatini are
attached to the lateral lamina of the tube, and when they contract
help to open the tubal lumen. These fibres have also been called the
dilator tubae muscle.
• Salpingo pharyngeus- it is a muscle of the pharynx, arises from
cartilage around Eustachian tube and inserts into the
palatopharyngeus muscle by blending witn its posterior fasciculous.It
opens the pharyngeal orifice of the ET tube during swallowing and
allows for equalization of pressure between them.
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38. Nerve supply
• Tubal mucosa- tympanic branch of cranial nerve IX
• Tensor veli palatine- mandibular branch of trigeminal
• Levator veli palatine- pharyngeal plexus
• Salpingo pharyngeus- pharyngeal plexus
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39. Endoscopic Anatomy
 Medial end forms tubal
elevation/torus
tubarius .
 Lymphoid collection
over torus is called
tubal tonsil.
 Postero-superior to
torus is fossa of
Rosenmuller.
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41. • Adult vs Infant
Adult Infant
length 36mm 18mm
Angle with horizontal 45 degree 10 degree
lumen narrower wider
Angulation at isthmus + _
cartilage rigid flaccid
Elastic recoil effective ineffective
Ostmann’s fat more less
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42. Infant E. tube
• Wider shorter and more horizontal
• So secretions even milk can regurgitate from nasopharynx to middle
ear if infant not fed in head up position
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43. Physiology
• The main function of the Eustachian tube is ventilation of the middle
ear and maintenance of equalized air pressure on both sides of the
TM (eardrum).
• Closed at most times, the tube opens during swallowing & yawning.
• This permits equalization of the pressure without conscious effort.
• During an underwater dive or a rapid descent in an airplane, ET tube
may remain closed in the face of rapidly increasing surrounding
pressure.
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44. • The pressure on both sides of the eardrum membrane can usually be
equalized by holding the nose and blowing, by swallowing, or by
wiggling the jaws.
• Opens actively by contraction of tensor veli palatine & passively by
contraction of levator veli palatine (it releases the tension on tubal
cartilage).
• Closes by elastic recoil of elastin hinge + deforming force of
Ostmann’s fat pad.
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48. ET function Tests
-VALSALVA TEST-principle: positive pressure in the
nasopharynx causes air to enter the ET tube
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49. • Tympanic membrane perforation- a hissing sound
• Discharge in the middle ear- cracking sound
• Only 65% of persons can do this test
Contraindications:
-Atrophic scar of tympanic membrane which can rupture
-Infection of nose and nasopharynx
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•Tonybee’s test
• Uses negative pressure
• Ask the patient to swallow while nose is pinched
• Draws air from middle ear to nasopharynx – inward movement of
• Tympanic membrane

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•Sonotubometry test
• It measures ET Opening
• Using a speaker which produces a tone inside the nose
• A microphone placed in the EAC such that opening of ET can be
detected as an increased in the sound reception from nasopharynx
• Tone is heard louder when tube is patent
• Tells duration for which tube remains open
• Provides info on active tubal opening

52. •Politzer test
-Done in children who are unable to perform valsalva test
-Olive shaped tip of the politzer’s bag is introduced into the patient’s
nostril on the side of which the tubal function is desired to be tested
-Other nostril closed and the bag compressed while at the same time
the patient swallows or says”ik, ik, ik”
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54. Catheterisation
• In this test, nose is first anaesthetized by topical spray of lignocaine
and then a Eustachian tube catheter, the tip of which is bent, is
passed along the floor of nose till it reaches the nasopharynx.
• Here it is rotated 90 degree medially and gradually pulled back till it
engages on the posterior border of nasal septum.
• It is then rotated 180 degree laterally so that the tip lies against the
tubal opening.
• A Politzer's bag is now connected to the catheter and air insufflated.
• Entry of air in to the middle ear is verified by an auscultation tube.
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55. • The procedure of catheterization should be gentle as it is known to
cause complications such as:
(a) Injury to eustachian tube opening which causes
scarring later.
(b) Bleeding from the nose.
(c) Transmission of nasal and nasopharyngeal infection into the middle
ear causing otitis media.
(d) Rupture of atrophic area of tympanic membrane if too much
pressure is used.
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58. • Symptoms of tubal occlusion
-Otalgia
-Hearing loss
-Popping sensation
-Tinnitus
-Disturbances of equilibrium
• Signs of tubal occlusion
-Retracted TM
-Congestion along the handle of malleus and pars tensa
-Transudate behind TM
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59. Clinical causes of ET obstruction
• Upper respiratory tract infection
• Allergy
• Sinusitis
• Nasal polypi
• Hypertrophic adenoids
• Nasopharyngeal tumour/ mass
• Cleft palate
• Down’s syndrome
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60. Retraction Pockets and Eustachian Tube
• In ventilation of the middle ear cleft, air passes from eustachian tube
to mesotympanum, from there to attic, aditus, antrum and mastoid
air cell system.
• Mesotympanum communicates with the attic via anterior and
posterior isthmus, situated in membranous diaphragm between the
mesotympanum and the attic. Anterior isthmus is situated between
tendon of tensor tympani and the stapes.
• Posterior isthmus is situated between tendon of stapedius muscle
and pyramid, and short process of incus.
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61. • In some cases, middle ear can also communicate directly with the mastoid
air cells through the retrofacial cells.
• Any obstruction in the pathways of ventilation can cause retraction pockets
or atelectasis of tympanic membrane, e.g.
(i) Obstruction of eustachian tube -+ Total atelectasis
of tympanic membrane.
(ii) Obstruction in middle ear -+ Retraction pocket in posterior part of
middle ear while anterior part is ventilated.
(iii) Obstruction of isthmus -+ Attic retraction pocket.
(iv) Obstruction at aditus -+ Cholesterol granuloma and collection of mucoid
discharge in mastoid air cells, while middle ear and attic appear normal.
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62. • Depending on the location of pathologic process, other changes such
as thin atrophic tympanic membrane, partial or total, (due to
absorption of middle fibrous layer), cholesteatoma, ossicular necrosis,
and tympanosclerotic changes may also be found.
• Principles of management of retraction pockets and atelectasis of
middle ear would entail correction/repair of the irreversible
pathologic processes and establishment of ventilation.
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63. Patulous Eustachian Tube
• In this condition, the eustachian tube is abnormally patent. Most of
the time it is idiopathic but rapid weight loss, pregnancy especially
third trimester, or multiple sclerosis can also cause it.
• Patient's chief complaints are hearing his own voice (autophony),
even his own breath sounds, which is very disturbing.
• Due to abnormal potency, pressure changes in the nasopharynx are
easily transmitted to the middle ear so much so that the movements
of tympanic can be 'seen with inspiration and expiration; these
movements are further exaggerated if patient breathes after closing
the opposite nostril.
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64. • Acute condition of patulous tube is self-limiting and does not require
treatment.
• In others, weight gain, oral administration of potassium iodide is
helpful but some long-standing cases may require cauterisation of the
tubes or insertion of a grommet.
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65. THANK YOU FOR YOUR ATTENSION
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