1 Anatomy of Nose and Paranasal SinusProf. Surayie Al Dousary Director of rhinology research chair

2 Nose and Paranasal Sinuses Ianatomy antomy -external nose &nasal cavity, paranasal sinuses, (blood supply, {nerve supply} in brief), physiology function- nose & paranasal sinus, congenital anomalies (in brief) {choanal atresia}

3 The Nose The nose consists of the external nose and the nasal cavity,Both are divided by a septum into right and left halves.

4 External Nose The framework of the external nose is made up above by the nasal bones the frontal processes of the maxillae the nasal part of the frontal bone Below, the framework is formed of plates of hyaline cartilage

5 External Nose

6 Nasal Muscles Procerous elevate the skin of dorsumNasalis compressor of naris Dilators naris Depressor septi External Nose

7 Blood Supply of the External NoseThe 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.

8 Nerve Supply of the External NoseThe infratrochlear and external nasal branches of the ophthalmic nerve (CN V) The infraorbital branch of the maxillary nerve (CN V).

9 Nasal Cavity The nasal cavity has Floor Roof Lateral wallMedial wall or septum

10 The Floor of Nasal CavityPalatine process of maxilla Horizontal plate palatine bone

11 The Roof of Nasal CavityNarrow It is formed anteriorly beneath the bridge of the nose by the nasal and frontal bones, in the middle by the cribriform plate of the ethmoid, located beneath the anterior cranial fossa, posteriorly by the downward sloping body of the sphenoid

12 The Nasal Septum Divides the nasal cavity into right and left

13 Lateral Nasal Wall In neonate In adultThe nasal & orbital floors are located at the same level Lateral nasal wall serves as the medial orbital wall Maxilla, contributes minimally in fetus & neonate In adult Only the upper half of the lateral nasal wall forms the medial orbital wall The nasal floor is at lower level than orbital floor The medial surface of the maxilla is incomplete (maxillary hiatus) The aperture of the hiatus is reduced by presence of palatine and lacrimal bones and the inferior concha

14 The Lateral Walls of Nasal CavityMarked by 3 projections: Superior concha Middle concha Inferior concha The space below each concha is called a meatus.

15 The Lateral Walls of Nasal CavityInferior meatus: nasolacrimal duct Middle meatus: Maxillary sinus Frontal sinus Anterior ethmoid sinuses Superior meatus: posterior ethmoid sinuses Sphenoethmoidal recess: sphenoid sinus

16 Blood Supply to the Nasal CavityFrom branches of the maxillary artery, one of the terminal branches of the external carotid artery. The sphenopalatine artery anastomoses with the septal branch of the superior labial branch of the facial artery in the region of the vestibule. The submucous venous plexus is drained by veins that accompany the arteries.

17 Nerve Supply of the Nasal CavityCN I – Olfactory Nerves (SVA) Anterior ethmoidal branch of V1 Posterior nasal branches of V2 Cut nasopalatine branch of V2 to septum

18 Lymph Drainage of the Nasal CavityThe lymph vessels draining the vestibule end in the submandibular nodes. The remainder of the nasal cavity is drained by vessels that pass to the upper deep cervical nodes.

20 Coronal & Sagital Cut

21 CADAVERIC

22 The Paranasal Sinuses The paranasal sinuses are cavities found in the interior of the maxilla, frontal, sphenoid, and ethmoid bones . They are lined with mucoperiosteum and filled with air. They communicate with the nasal cavity through relatively small apertures.

23 Drainage of Mucus and Function of Paranasal SinusesThe mucus produced by the mucous membrane is moved into the nose by ciliary action of the columnar cells. Drainage of the mucus is also achieved by the siphon action created during the blowing of the nose. Functions: Resonators of the voice They also reduce the skulls weight Help wam and moisten inhaled air Act as shock absorbers in trauma

24 Ciliary Pattern in Sinuses Mucosa

25 Frontal Sinuses Rarely symmetrical Contained within the frontal bone .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. Opens into the middle meatus

26 Maxillary Sinus Pyramidal in shape Paired & symmetricLocated within the body of the maxilla behind the skin of the cheek. The roof is formed by the floor of the orbit, and the floor is related to the roots of the 2nd premolars and 1st molar teeth. The maxillary sinus opens into the middle meatus of the nose

27 Sphenoidal Sinuses Lie within the body of the sphenoid boneBelow sella turcica Extends between dorsum sellae and post clinoid processes Opens into the sphenoethmoidal recess above the superior concha

28 Ethmoid Sinuses They are anterior, middle, and posteriorThey are contained within the ethmoid bone, between the nose and the orbit Anterior & middle Drains into middle nasal meatus Posterior Drain into superior nasal meatus Separated from the orbit by a thin plate of bone so that infection can readily spread from the sinuses into the orbit

29 Nasal Swelling in childhood

30 Normal Function of PNS Patent Ostia Normal Ciliary FunctionNormal Quality of Mucous Disturbance of these Function will lead to sinusitis

31 Physiology of the nose Three major functions of the nose:Olfaction Respiration (the most important) Defense Additional minor functions Aiding and modifying voice production Providing vocal resonance Serving as a secondary sex organ

32 Modification of inspired airHumidification Nose adjust precisely the inspired air to have a humidity of 85 % This enhances the gas exchange Large portion returned to the nasal mucosa during exhalation. This prevents overdrying of the nasal mucosa and thickening of the nasal secretions. Warms the inspired air The rich capillary beds that make up the side wall of the nose, along with their accompanying venous sinusoids

33 Nasal Valve The smallest cross-sectional diameter and greatest resistance of the airway The muscle activity prevents alar collapse during inspiration. Resistance in this segment is created by the turbinate size, which is altered by the vascular tone and blood volume of the nasal sinusoids. Induced by exercise, posture changes, and hyperventilation. Chemical irritants, medications, pain, and emotion

34 Nasal Cycle Alternating changes in patency of the right & the left nasal cavities Occur in rhythmic sequence in about 80 % of normal individuals The total resistance to the nasal airflow remains constant Controlled through the Autonomic adrenergic centers Hypothalamic control center If the cervical ganglion is sectioned, there is abolition of the nasal cycle on the same side

35 Olfaction Important in food choices and in social interactionWarning sign for toxic gases and spoiled foods. To smell a substance, it must some how reach the olfactory mucosa located in the roof of the nose The odor-producing substance must have a vapor pressure and must be relatively water- and lipid-soluble in order to be sensed.

36 Anosmia Nasal obstruction and nasal infection.the receptor molecule cannot reach the olfactory mucosa to stimulate a response. Nasal polyposis and nasal deformities are reversible conditions in adults. Infections and allergies cause temporary interruption of smell, and olfactory capability returns when the conditions resolve. smell can trigger an asthmatic attack and can worsen emphysema. ? trigeminal reflex, which is induced by a chemical irritant stimulating the nasal mucosa,and leads to reflex bronchial constriction

37 Immunology Secretory immunoglobulin A (IgA) is the major immunoglobulin found in nasal secretions The concentration of IgG (3 per cent) and IgM (l per cent) increases during actual infections, ? transudation of plasma resulting from mucosal injury

38 Diseases of the Nose CongenitalAtresia and Stenosis of anterior nares Caused by non canalozation of an epithelial plug between the median and lateral nasal process. Rx: Excision Atresia of posterior nares (congenital choanal atresia) Types: - Bony most commonly - Membranous - Mixed

40 Diseases of the Nose Clinical Features: Unilateral atresiaNasal obstruction Excessive nasal discharge Bilateral atresia Asphyxia Nasal discharge

41 Bilateral Choanal atresiaDiagnosis: Total absence of nasal air flow Plastic catheter cannot be passed through the nose Post-rhinoscopy Radiographs Treatment: Emergency Transnasal perforation Trans-palatal excision

43 Choanal atresia uinilateral bilateral

44 Developmental errors of the anterior neuroporeEncephalocels Nasal glioma Dermoid

46 Encephalocele

48 Investigation

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50 Nasal Glioma

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52 Nasal Glioma

53 Nasal Dermoids

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