the nose the nasopharynx the paranasal sinuses class2014-20… · to describe the external nose. to...

The Nose

The Nasopharynx

The Paranasal sinuses

To describe the external nose.

To define the nasal cavity & its contents.

To describe the nasal part of the pharynx.

To list the paranasal sinuses.

The External Nose:

Surface anatomy:

The External Nose:

Skeleton:

1-The bony part: formed by nasal bones

2-The cartilagenous part:

A) Lateral nasal cartilage; attached to lower

border of nasal bone

B) Alar cartilage; from rounded part of the

nostril

A

B

Arterial supply:

1- Facial artery.

2- Infraorbital artery.

Veins:

Accompany arteries.

Nerves:

1- Midline; Infratrochlear & external

nasal (Va)

2- Lateral side; infraorbital (Vb)

The Nasal Cavity:

Skeleton:

1- Lateral wall:

-Sphenoid

-Palatine

-Ethmoid

-Maxilla

-Inferior concha

E

M

IC

P

S

2- Floor:

-Formed by the hard palate.

-Fixes the septum by the maxillary

crest

3- Roof:

-Is formed by the cribriform plate

-Communicates with anterior cranial

fossa

-Lined with olfactory neuro-epithelium

-Olfactory nerves leave the roof

through the cribriform plate to the

brain

-Olfaction takes place in the roof

Anosmia:

-Any pathology blocking the nose

prevent odours from reaching the roof

-May be of neurological origin

4-Medial wall (septum):

-Perpendicular plate of ethmoid

-Vomer

-Septal cartilage

-Maxillary crest

E

V

SC

Deviated nasal

septum

Parts of the nose:

•The vestibule; is the skinny part of the nasal cavity

•The choanae; are the posterior nasal apertures which open to the

nasopharynx

Congenital choanal atresia

* Unilateral

* Bilateral

•The conchae (Turbinates):

-Three scroll-like projections in the lateral wall of the nose

-The upper two are parts of the ethmoid while the lower is a separate bone

-Their covering mucosa is highly vascular & contain erectile tissue so their

size is not fixed

-Functions; increase mucosal area & protect the meatuses

Case scenario …

A 35 years old lady consulted the ENT

surgeon for severe nasal obstruction of

few months duration, her husband said

that her snoring at night is intolerable!

On examination, the physician found

severe deviation in her nasal septum, with

hypertrophied inferior turbinates.

CT scan confirmed the diagnosis, &

revealed intact paranasal sinuses.

She was prepared for turbinectomy &

septoplasty.

Concha bullosa (normal 50%):

-Air filled cavity within turbinate

-May cause nasal obstruction

•Meatuses:

-Each concha overlies a meatus

-Consequently we have superior,

middle & inferior meatuses

-Inferior meatus receives the

nasolacrimal duct from the orbit

-Other meatuses receive

openings of the paranasal

sinuses

-Spheno-ethmoidal recess is the

space between the superior

concha & nasal roof

-The middle meatus is composed of

two structures:

1- Bulla ethmoidalis: spherical bulge

fromlateral nasal wall

2- Hiatus semilunaris: crescentic cleft

inferior to the bulla

Osteomeatal complex:

-Radiological term referring to the site

of these structures

-Its obstruction predispose to chronic

sinusitis

1

2

Nerve supply:

Lateral wall: (in quadrants)

1- Anterior ethmoidal n.

2- Anterior superior alveolar n.

3- Posterior superior lateral nasal n.

4- Greater & lesser palatine n.

•(1) is ophthalmic branch

•(2) is maxillary branch

•Others are pterygopalatine

ganglion branches

1

2

3

4

The septum: (in halves)

1- Nasopalatine nerve:

-Branch of pterygopalatine ganglion

-Supplies postero-inferior half

2- Anterior ethmoidal nerve:

-Branch of ophthalmic nerve

-Supplies anterosuperior quadrant

Arterial supply:

Like nerve supply

Venous drainage:

*Anterior ½; anterior facial vein

*Posterior ½; pterygoid v. plexus

Epistaxis “Little’s area”

The pterygopalatine ganglion:

-A parasympathetic ganglion lies in the

pterygopalatine fossa (behind the orbit)

-Its parasympathetic root from facial

nerve (greater petrosal branch)

-Its sensory root from maxillary nerve

-Gives 5 postganglionic branches:

1- Nasopalatine

2- Posterior superior lateral nasal

3- Pharyngeal

4&5- Greater & lesser palatine

The nasopharynx:

•The part of the pharynx lying superior to

the hard palate

•It is completely respiratory

•Its wall is strengthened by the

pharyngobasilar fascia

•Supplied by pharyngeal branch of

pterygopalatine ganglion

Structures in the nasopharynx:

1- Pharyngeal tonsil: just below the roof.

2- Tubal tonsils: around the openings of auditory tubes.

3- Eustachian (auditory) tube openings: one on each side, connect the

nasopharynx to the middle ear cavity.

1

3

2

4- Salpingopharyngeal fold:

muscular fold descends behind

the tubal orifice.

5- Pharyngeal recess: projects

posterolaterally behind the fold.

5

4

Adenoids (Enlarged pharyngeal tonsils)

Eustachian tube dysfunction Causes impaired hearing

The paranasal sinuses:

•Pneumatic areas in the frontal,

ethmoidal, sphenoidal & maxillary

bones.

•Their mucosa is continuous with that

of the nasal cavity through the

meatuses

•The maxillary sinus is well developed

at birth, the frontal & sphenoidal

develop at the 7th year of life while the

ethmoidal develop at puberty.

•Supplied by regional vessels & nerves

•Function !??

The frontal sinuses:

•2 pyramidal sinuses within the frontal bone, rarely symmetrical

•Drain to the anterior part of the hiatus semilunaris

•Supplied by supraorbital & supratrochlear vessels & nerves.

The ethmoidal sinuses:

•3 sinuses in each lateral mass of the ethmoid; anterior, middle & posterior

•They are trabeculated forming air cells

•Anterior & middle drain to the middle meatus

•The posterior drains to the superior meatus

•Anterior & posterior vessels & nerves supply them

ACF

Orb

NC Mx

The sphenoidal sinuses:

•2 sinuses in the body of sphenoid

•Opens in the spheno-ethmoidal recess.

•Supplied by the posterior ethmoidal vessels & nerves

The maxillary sinuses:

•2 sinuses, one occupies each maxillary body

•They are pyramidal cavities with their bases directed to the lateral nasal wall

•The big openings in the lateral nasal wall are blocked by the inferior conchae

•Drain in the posterior part of hiatus semilunaris

•Supplied by superior alveolar, infraorbital & zygomaticofacial vessels & nerves

Applied anatomy:

Sinus pain refers to:

Forehead

Nose

Orbit

Upper teeth

Antral washout