By: Aminah Alessa . Hawra Alabad . Zainab Alsaleh Anatomy of nose and physiology By: Aminah Alessa . Hawra Alabad . Zainab Alsaleh

Nose Origin: Originates from the nasofrontal process during 4th to 8th week of IU life. Consists of : - External nose. - Nasal cavity.

External nose

External nose: It is pyramidal in shape with its root up and the base directed downwards. Consist of: Osteo-cartilaginous structure. Muscles of the nose. Nasal skin.

OSTEOCARTILAGINOUS Upper one-third of the external nose is bony part: made up of two nasal bones meeting in the middle, resting on the frontal bone. lower two thirds are cartilaginous consist of : upper lateral cartilage: Extending from the lower surface of the frontal bones, to connect with the alar cartilage. lower lateral cartilage( alar) : U-shaped cartilage. Medially, they connect with the upper lateral cartilage. sesamoid cartilage: A supporting cartilage planted on a bone. Connects with the lateral part of the Alar cartilage, but minimally contributes to nostrils’ structure. septal cartilage: Running on the entire length of the nose anteriosuperiorly.

Internal nose

Internal nose It is divided into right and left nasal cavities by nasal septum. Each nasal cavity consists of a: skin-lined portion—the vestibule a mucosa-lined portion, the nasal cavity proper.

LINING MEMBRANE OF INTERNAL NOSE Vestibule: Anterior and inferior part of nasal cavity Lined by skin containing hair, hair follicles, sebaceous glands. Olfactory region: Upper one-third of lateral wall (up to superior concha). Lined with olfactory mucous membrane and contains nerve endings sensitive to the reception of smell. Respiratory region: Lower two-thirds of the nasal cavity Mucous membrane shows varible thickenings. It is highly vascular and also contains erectile tissue

NASAL CAVITY PROPER a lateral wall a medial wall a roof and a floor.

Lateral Walls The lateral wall of the nose is subdivided into three areas which are: Vestibule Conchae - They are bony plates covered with mucous membrane. - Marked by 3 projections: Superior concha (turbinate). Middle concha (turbinate). 3. Inferior concha (turbinate). Meatuses The cavity below and lateral to each concha (superior, middle, and inferior meatuses). The small space above the superior concha is the sphenoethmoial (suprameatal) recess.

Lateral Walls Sphenoethmoidal recess: - It receives the opening of the sphenoidal air sinus. Superior meatus: It receives the opening of posterior ethmoidal air sinus. Inferior meatus: It receives the nasolacrimal duct. Middle meatus: It receives the following openings: Anterior ethmoidal air sinus. Frontal air sinus. Maxillary air sinus.

B. Medial Walls Osteo-cartilaginous partition between the two nasal cavities called nasal septum. Nasal septum consists of three parts: 1. Columellar septum. 2. Membranous septum. columellar and membranous parts are freely movable from side to side.

3. Septum proper. It consists of osteocartilaginous framework, covered with nasal mucous membrane. Its principal constituents are : Anterior: Septal cartilage. Superior: Perpendicular plate of ethmoid bone. Posteroinferiorly : Vomer. Inferior : crest of the maxillary bone  Inferior : crest of the palatine bone 

C. Roof Anterior: formed by nasal bones& nasal spine of the frontal bone Posterior: formed by the body of sphenoid bone Middle: formed by the cribriform plate of ethmoid bone through which the Olfactory nerves enter the nasal cavity.

D. Floor Anterior: 3/4th formed by palatine process of the maxilla Posterior: 1/4th formed by the palatine bone.

Blood supply of lateral wall INTERNAL CAROTID SYSTEM: 1. Anterior ethmoidal. 2. Posterior ethmoidal. EXTERNAL CAROTID SYSTEM: 1. Posterior lateral nasal Branches → From sphenopalatine artery. 2. Greater palatine artery → From maxillary artery. 3. Nasal branch of anterior superior dental → From infraorbital branch of maxillary Artery. 4. Branches of facial artery to nasal vestibule. Branches of ophthalmic artery

Blood Supply to the Nasal septum INTERNAL CAROTID SYSTEM: 1. Anterior ethmoidal artery 2. Posterior ethmoidal artery EXTERNAL CAROTID SYSTEM: 1. Sphenopalatine artery → (maxillary artery) gives nasopalatine and posterior medial nasal branches. 2. Septal branch of greater palatine artery → maxillary artery. 3. Septal branch of superior labial artery → facial Artery. Branches of ophthalmic artery

NERVE SUPPLY Olfactory nerves: They carry sense of smell and supply olfactory region of nose. Which pass through the cribriform plate and end in the olfactory bulb 2.Nerves of common sensation. They are: Anterior ethmoidal nerve. Branches of sphenopalatine ganglion. (c) Branches of infraorbital nerve 3. Autonomic nerves.

Lymph Drainage of the Nasal Cavity The anterior part : drains into submental and submandibular lymph nodes. posterior part: drains into the retropharyngeal nodes. All of these nodes finally drain into the upper deep cervical lymph nodes

Para-nasal sinuses

Para-nasal sinuses Functions: The paranasal sinuses are air-filled cavities in the interior of the maxilla and the frontal, sphenoid, and ethmoid bones. The sinuses develop as outgrowths from the nasal cavity; hence they all drain directly or indirectly into the nose. Functions: 1. Warming and humidifying the inspired air. 2. Reduce the skull weight. 3. They add resonance to the voice. 4. Act as shock absorbers in trauma. 5. Immunologic defence against microbes.

Para nasal air sinuses: Frontal sinuses Ethmoid cells Sphenoid sinuses Maxillary sinuses

Maxillary sinuses Relations: Are the largest of all paranasal sinuses. Completely fill the bodies of the maxillae. Symmetric paired, one on each side pyramidal in shape ,lying just under the check. with apex directed laterally and the base deep to the lateral wall of adjacent nasal cavity . Present at birth. Relations: The superolateral surface “roof” : floor of the orbit. Anterolateral surface: roots of the 2nd premolar and 1st molar teeth Posterior wall: infratemporal fossa.

Ethmoid cells The ethmoid cell on each side fill the ethmoidal labyrinth. Located between nose and orbit. Variable number of individual air chamber. Divided into anterior, middle, posterior ethmoid cells based on location of their apertures on lateral wall of the nasal cavity. Anterior ethmoid cell open into the ethmoidal infundibulum or frontonasal duct.” middle nasal meatus)” Middle ethmoidal cells open into ethmoidal bulla.” middle nasal meatus) Posterior ethmoidal cell open into lateral wall of superior nasal meatus.

Frontal sinuses Relation: Paired rarely symmetrical. Contained within frontal bone. Separated from each other by a bony septum . Each sinus is roughly triangular Relation: Posterior wall :anterior cranial fossa Floor: is formed by the upper part of orbit. Opens into the middle meatus

Sphenoidal sinuses Lie within the body of the sphenoid bone Below Sella turcica (extends between dorsum sellae and post clinoid processes) Opens into the sphenoethmoidal recess above the superior concha. Laterally related to ophthalmic nerve , internal carotid artery So it’s sensitive area for surgeon when they need to remove pituitary gland .

Physiology of Nose 1. Respiration. 2. Air-conditioning of inspired air. 3. Protection of lower airway. 4. Vocal resonance. 5. Nasal reflex functions. 6. Olfaction.

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