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Nose and paranasal sinuses By Dr. Adel Sahib Al-Mayaly

Nose External nose Nasal cavity paranasal sinuses

Introduction The nose is an integral part of the respiratory tract. It contains the peripheral organ of smell (Olfactory area). It is a resonating chamber for voice It includes the external nose and nasal cavity The nasal cavity is divided into right and left cavities by the nasal septum (midline partition).

Functions of the nose 1- Olfaction (smelling). 2- Respiration (breathing), 3- Filtration of dust. 4- Humidification of inspired air. 5- Reception and elimination of secretions from the paranasal sinuses and nasolacrimal ducts. 6- Resonating chamber.

Nasal profile

External Nose The external nose triangular-shaped projection in the center of the face . It consists of osteocartilaginous framework covered by muscles and skin. Its upper end or root is continuous with the forehead . At its lower end (base) are the nares (nostrils). The sides of the nose meet in the midline anteriorly to form the dorsum. The upper part of the dorsum is the bridge and at the lower end of the dorsum is the tip of the nose. The lower flared part of the side of the nose is the ala.

The external nose

The framework of the external nose It is made up 1- Above by:- Bony the nasal bones, the frontal processes of the maxillae, and the nasal process of the frontal bone 2- Below:- Cartilaginous the framework is formed of plates of hyaline cartilage ( two upper lateral, two alar & septal process).

The external nose Framework(bony)

Blood Supply of the External Nose The skin of the external nose is supplied by branches of the ophthalmic and the maxillary arteries The skin of the ala and the lower part of the septum are supplied by branches from the facial artery.

Nasal Cavity It extends from;- the nostrils in front to the posterior nasal apertures or choanae behind. it is divided into two cavities by the nasal septum. Each cavity has 4 walls:- 1- Medial & lateral. 2- Roof & floor

Nasal cavity Nasal vestibule:- is the anterior and inferior part of nasal cavity. It is lined by skin and contains sebaceous glands,hair follicles and hair(vibrissae) easy to infection.

The lateral wall has three projections of bone called (turbinates or conchae) superior, middle, and inferior nasal conchae The space below each concha is called a meatus. Inferior, Middle & Superior meati Sphenoethmoidal Recess is a small area above the superior concha. It receives the opening of the sphenoid air sinus

Lateral wall

Middle Meatus The middle turbinate has by far the greatest functional importance. Most of the drainage tracts from the surrounding paranasal sinuses open into the middle meatus. Maxillary , frontal & anterior ethmoid sinuses Collectively called anterior group

Medial Wall (Nasal septum) The nasal septum has a: •Bony part •Cartilaginous part •Membranous part

Components of nasal septum Bony part: •Posterosuperiorly: The perpendicular plate of the ethmoid. •Posteroinferiorly: Vomer BONE Cartilaginous part: •Anteriorly quadrilateral septal cartilage •Medial crus of the alar cartilage Membranous part: •This is the anterior most part of the nasal septum lined by skin and fibrofatty tissue.

Septum deviation Result in－ Nasal obstruction Nasal bleeding Headache Anosmia Sinusitis External deformity

Roof & Floor Roof :- Is by cribriform plate of ethmoid Floor:- Hard palate. a- palatal processes of palatine bone & horizontal plates of maxilla

Arterial supply of the nose Sphenopalatine artery;- - It is a branch from the maxillary artery (main arterial supply). Septal branch of the superior labial artery from facial artery.

Arterial supply of the nose 3- Ascending branch of the greater palatine artery 4- Anterior & post. Ethmoidal Aa. (Little’s area). Or “Kieselbach's plexus This area is a common site for epistaxis (bleeding from the nose).

Paranasal sinuses Are air-filled spaces in the facial & skull bones The paranasal sinuses consist of the paired frontal, ethmoid ,maxillary, and sphenoid sinuses.

Maxillary Sinus The maxillary sinus usually is the largest of the paranasal sinuses and is situated in the body of the maxilla. Anterior wall:- The facial surface of maxilla. Posterior wall:- The infratemporal surface. Medial wall :- The nasal cavity. The roof:- Floor of the orbit. the floor is related to the roots of the premolars and molar teeth. The maxillary sinus drains into the middle meatus of the nasal cavity

Ethmoid Sinuses 1he ethmoid sinuses consist of a variable number of separate cavities. It lies between the upper part of the lateral nasal wall and the medial wall of the o:rbit. Each sinus is divided into 1- anterior ethmoid sinus: - drains into middle meatus 2- posterior ethmoid :- drains into the superior meatus

Frontal Sinuses The two frontal sinuses are contained within the frontal bone. They are separated from each other by a bony septum. Each sinus is roughly triangular. Extending upward above the medial end of the eyebrow and backward into the medial part of the roof of the orbit. Each frontal sinus opens into the middle meatus via the nasofrontal recess.

Sphenoid Sinuses The two sphenoid sinuses lie within the body of the sphenoid bone Each sinus opens into the sphenoethmoidal recess above the superior concha.

Paranasal Sinuses and Their Site of Drainage into the Nose Middle meatus 1- Maxillary sinus 2- Frontal sinuses Sphenoethmoidal recess 3- Sphenoid sinuses 4- Ethmoid sinuses Anterior Superior meatus Posterior

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