بسم الله الرحمن الرحيم

بسم الله الرحمن الرحيم

Anatomy of Nose

Objectives: • By the end of this lecture we are going to be able to: • Describe the anatomical structure and features of the nose • Identify the bones forming the nasal cavity • Recognize arterial supply, and venous drainage of the nose • Identify 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 nose I. 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 nose b. 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 nose 1. 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 Ganglion Type: 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 nose I. 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 Sinuses Definition: - 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.

Thank You Prof.: Dr. Wafaa Abdel-Rahman

بسم الله الرحمن الرحيم