Objectives:By the end of this lecture we are going to be

able to:Describe the anatomical structure and

features of the noseIdentify the bones forming the nasal cavityRecognize arterial supply, and venous

drainage of the noseIdentify different Para nasal sinuses and their

functions

nasal cavity- The cavity of the nose is subdivided into

right and left halves by the nasal septum. - The two halves open anteriorly on the face

through the nostrils (anterior nares), and open posteriorly into the nasopharynx through the posterior nasal aperture.

Bony skeleton of the noseI. Roof, formed by: - Anterior part------ Nasal part of the

frontal bone + Nasal bone.- Middle part ------ Cribriform plate of

the ethmoid bone.- Posterior part------Body of the

sphenoid bone.I. Floor, formed by:- Anteriorly: Palatine process of the

maxilla.- Posteriorly : Horizontal plates of the

palatine bone.III. Medial wall (nasal septum),

formed by: - Postero-inferior-------Vomer.- Superiorly ----- Perpendicular plate

of the ethmoid bone.- Antero-inferior -----Septal cartilage.

(Roof, floor, and medial wall of the

nose)

Lateral wall of the nose- The lateral wall of the nose is

subdivided into three areas which are:

A. Vestibule B.Nasal conchae and meatuses:1. Conchae- They are bony plates covered with

mucous membrane. - They are three (superior, middle,

and inferior nasal conchae).2. Meatuses- They are depressions below and

lateral to each concha (superior, middle, and

inferior meatuses).-Superior meatus : It receives the

opening of posterior ethmoidal air sinus.

Lateral wall of the noseb. Middle meatus : It has* Bulla ethmoidalis: - It is a rounded elevation where

the middle ethmoidal air sinus opens in it.

* Hiatus semilunaris: - It is a crescenteric groove ()

lying below the bulla ethmoidalis. - It receives the following

openings: i. Anterior ethmoial air sinus. ii. Frontal air sinus. iii. Maxillary air sinus.c. Inferior meatus (below the

inferior nasal concha):- It receives the nasolacrimal duct.d. Spheno-ethmoidal recess:- It is a triangular fossa between the

superior concha and the roof of the nose.

- It receives the opening of the sphenoidal air sinus.

Arterial supply of the nose1. Sphenopalatine artery- It is a branch from the maxillary artery

(main arterial supply).

2. Septal branch of the superior labial artery from facial artery.

3. Ascending branch of the greater palatine artery from the maxillary artery .

- There is anastomoses between the above three arteries to form “Kieselbach's plexus” on the antero-inferior part of the nasal septum (Little’s area).

- This area is a common site for epistaxis (bleeding from the nose).

4. Anterior and posterior ethmoidal branches of the ophthalmic artery. supply the roof and upper parts of the lateral wall and septum.

 

Sphenopalatine GanglionType: Parasympathetic

ganglion.Site: In the pterygopalatine

fossa.Roots (preganglionic fibers):1. Sensory: From the maxillary

nerve.2. Sympathetic supply: Deep

petrosal nerve which arises from the sympathetic plexus around the internal carotid artery.

3. Parasympathetic: Greater petrosal nerve (from facial N)

Sphenopalatine Ganglion (branches)1. Postganglionic secreto-

motor fibers which supply the lacrimal gland.

2. Lesser palatine nerves.3. Greater palatine nerve .- It gives the lateral

posterior inferior nasal nerves.

4. Lateral and medial posterior superior nasal nerves.

5. Nasopalatine nerve. ( long sphenopalatine)

6. Pharyngeal branch to the pharynx.

7. Branches to the orbital periosteum.

NB: The postganglionic branches of the sphenopalatine ganglion supply the mucous glands of the palate, nose, nasopharynx and the lacrimal gland.

Nerve supply of the noseI. Lateral wall- Olfactory area (1 cm) Olfactory nerves.

(this area includes the roof and upper parts of the septum and lateral nasal walls)

- Vestibular area Infraorbital nerve.

- Respiratory area of the lateral wall: a. Antero-superior anterior ethmoidal N.

b. Antero-inferior (inf. concha) Internal nasal nerve(from anterior ethmoidal N)

c. Postero-superior Lateral posterior superior nasal brs.

d. Postero-inferior Lateral posterior inferior nasal brs (from greater palatine N).

II. Nasal septum- Olfactory area Olfactory N. - Anterior part Internal nasal N. (from the anterior ethmoidal nerve).

- Postero-superior part Medial posterior superior nasal branches. (from

sphenopalatine ganglion). - Postero-inferior part Nasopalatine nerve. ( long sphenopalatine nerve).N.B: The nasopalatine nerve, greater and lesser palatine nerves, medial

and lateral posterior superior nasal nerves, and the posterior inferior nasal nerve are branches from the sphenopalatine ganglion.

Para-nasal Air SinusesDefinition: - They are air-filled spaces in certain

bones which form the boundary of the nasal cavity.

- They open into the lateral wall of the nose.

Functions:1. Warming and humidifying the inspired

air.2. Diminishing the weight of the skull.3. They add resonance to the voice.

Types: 1. Maxillary sinus -------- Inside

the body of the maxilla.2. Frontal sinus -----------

Between the two plates of the frontal bone.

3. Sphenoid ---------------- Inside the body of the sphenoid bone.

4. Ethmoid ----------------- Inside the lateral part of the ethmoid bone

- All the sinuses are present at birth except the frontal sinus which appears during the second year.

Prof.: Dr. Wafaa Abdel-Rahman