THE NOSE AND THE NOSE AND PARANASAL SINUSES PARANASAL SINUSES Dr. Mohamad S. Aziz Otolaryngologist CABMS (ORL-HNS) ENT Dept, College of Medicine, University of Mosul Undergraduate, The Nose, 2016/2017

Anatomy of the Nose

The External Nose The external nose is supported by bone and cartilage. The bony part is formed mainly by the nasal bones and by the frontal process of the maxillary bone. The cartilaginous portion is formed by several cartilages which support and give shape to the lower part of the nose.

The Nasal Septum Is the midline partition of the nasal cavity. It is formed by: Anteriorly  quadrilateral cartilage. Posterosuperiorly  perpendicular plate of ethmoid. Posteroinferiorly  vomer.

The nasal septum

The nasal septum

The Nasal Vestibule Is the entrance of the nasal cavity lined by hair-bearing squamous epithelium which ends at the mucocutaneous junction at which the nasal cavity begins. This hair is called the vibrissae.

The Nasal Cavity Are two irregular cavities extending from the vestibule (anterior nares) to the nasopharynx (posterior nares or choanae) . The nasal cavity has its axis at right angle to the face. The lining of the cavity is mainly pseudostratified ciliated columnar epithelium (respiratory type).

Boundaries Floor: maxilla and palatine bones. Roof: Nasal bones, cribriform plate of ethmoid and sphenoid bone. Medially: nasal septum. Laterally: there is a system of ridges (turbinates or conchae), each of which overhangs a groove (meatus). The turbinate is formed from erectile tissue covered by a mucous membrane.

The turbinates are three in number The turbinates are three in number. The superior and middle turbinates are part of the ethmoid bone, while the inferior turbinate is a separate bone.

The lateral nasal wall Inferior meatus: nasolacrimal duct Middle meatus: Maxillary sinus Frontal sinus Anterior ethmoid Superior meatus: posterior ethmoid Sphenoethmoidal recess: sphenoid sinus Sagital section

Blood Supply 1. Sphenopalatine artery (maxillary). 2. Greater palatine artery (maxillary). 3. Superior labial artery (facial). (External carotid artery) 4. Anterior ethmoidal artery (ophthalmic artery) 5. Posterior ethmoidal artery (ophthalmic artery) (Internal carotid artery) These vessels anatomse forming Kiesselbach’s plexus in Little’s area.

Venous Drainage Lymphatic Drainage Facial + ophthalmic vein  cavernous sinus. Submandibular, retropharyngeal and deep cervical chain. Lymphatic Drainage

Nerve Supply 1. Sensory: ophthalmic (anterior ethmoid) and maxillary (sphenopalatine) nerve. 2. Secretory: Vidian nerve (nerve of pterygoid canal) which is formed by the junction of the greater petrosal nerve, a branch of the facial nerve (parasympathetic) and the deep petrosal nerve (sympathetic) derived from the sympathetic plexus on the internal carotid artery .

- Greater petrosal nerve (parasymp - Greater petrosal nerve (parasymp.)  Dilates blood vessels + enhance glandular secretion. - Deep petrosal nerve (symp.)  constricts blood vessels. 3. Olfactory: The olfactory epithelium which is yellowish in colour occupies the cribriform plate, the upper one third of lateral nasal wall (up to superior turbinate) and corresponding part of nasal septum. The oflactory nerves (18-20) on each side  pass through the cribriform plate to synapse in the oflactroy bulb. Injury to these nerves can open CSF space leading to CSF rhinorrhea or meningitis.

The Paranasal Sinuses

Are air filled cavities located inside the facial bones, lined by an evagination of the mucous membrane of the nose and have communication with the nasal cavity. Ant. Group Frontal. Maxillary (Middle meatus) Anterior ethmoidal Post Group Posterior ethmoidal (Superior Meatus) Sphenoid (Sphenoethmoidal recess)

Maxillary Sinus (Antrum of Higmore) This sinus is pyramidal in shape with base towards lateral wall of nose and apex directed laterally into the zygoma. Its roof is the floor of the orbit and its floor lies over the 1st premolar – 3rd molar teeth. The ostium of the sinus is situated high in the medial wall (1 cm) and hence drainage is dependent on ciliary action and not gravity.

Frontal Sinus The sinus is not present at birth but appear at the age of 5 years. The sinus is frontal in location ethmoidal in origin. The frontal sinuses are rarely symmetrical and they are separated by a thin bone. The roof of the orbit forms the floor of the frontal sinus.

Ethmoidal Sinuses The ethmoid bone is made up of five parts; the perpendicular plate, the horizontal cribriform plate, the crista galli and two lateral labyrinths of cells suspended by the horizontal plate.

The ethmoidal sinuses are multiple air cells (7-15) in number and divided into anterior and posterior groups which drain respectively into middle and superior meati. They are separated from the orbit by a thin plate of bone known as lamina papyracea.

Sphenoid Sinus This sinus occupies the body of the sphenoid bone and drains into the sphenoethmoidal recess. The pituitary gland is located on its roof whereas the lateral wall is in contact with the cavernous sinus and its contents (internal carotid artery, and II, III, IV, V and VI cranial nerves). The Vidian nerve passes below this sinus.

Physiology of the Nose

Functions of the Nose 1. Olfaction. 2. Respiration a. Provide an airway for respiration. b. Filtration of air. c. Humidification and warming of the inspired air. 3.Vocal resonance. 4. Collect moisture from the expired air to prevent excessive loss. 5. The mucus is transported by the action of the cilia and contains antibodies which act as a defense mechanism

olfaction Particles Dissolved in mucous Carried to olfactory mucosa [Nerve endings] Olfactory bulb Olfactory nucleus, hypothalamus & thalamus

Physiology of the Paranasal Sinuses 1. Air conditioning of the inspired air. 2. Reduce the weight of the skull (shock absorber). 3. Vocal resonance. 4. Thermal insulation of the skull base. Nasal Cycle Nasal mucosa undergoes rhythmic cyclical congestion and decongestion, thus controlling the airflow through nasal chambers. Nasal cycle varies every 2-4 hours.

Symptoms of Nasal Diseases I. Nasal obstruction: Anatomical abnormality: Congenital choanal atresia or deviated nasal septum. Abnormality of the mucous membrane: Nasal polyposis or turbinate hypertrophy. Abnormalities of autonomic control of the mucosa: Vasomotor rhinitis.

Symptomatology: Bilateral Obstruction Nasal 1- Congenital Bil. Choanal atresia Deviated septum 2- Traumatic Foreign body Accident: Fracture- Haematoma Iatrogenic: Pack-Haematoma 3- Inflammatory Acute nonspecific: Common cold-Abscess Acute specific: Diphtheria Chronic nonspecific: At. - Hypertrophic Chronic specific: $ – T.B. - Scleroma 4- Neoplastic Benign: Ostioma -papilloma Malignant: Carcinoma - Sarcoma 5- Others Allergy Polyps

II. Nasal Discharge: -Watery clear discharge: Onset of common cold, allergic rhinitis or CSF rhinorrhea. -Mucopurulent: Yellow pus: Sinusitis. Unilateral foul discharge in a child: FB in the nose. Crusts in adults: Atrophic rhinitis. -Thick blood stained discharge: Tumour. -Postnasal mucopurulent discharge: Disease of the posterior group of sinuses.

III. Sneezing: Allergic rhinitis or common cold. IV. Pain: Severe local pain: Folliculitis. Early morning headache: Sinusitis. V. Epistaxis.

VI. Disturbance of smell: 1. Anosmia and hyposmia: Complete or partial loss of the sense of smell. It is often described as loss of taste as flavours are largely perceived through the olfactory apparatus. The causes are: -Nasal obstruction from common cold or nasal polyposis. -Vasomotor rhinitis. -Peripheral neuritis particularly following influenza virus. -Atrophic rhinitis. -Trauma: Base of skull fracture involving the cribriform plate.

2. Cacosmia: The perception of a bad smell. The causes are: -Maxillary sinusitis. -Foreign body in the nose. -Chronic suppurative otitis media. Pus discharge through Eustachian tube.

3. Parosmia: The perversion of the sense of smell or subjective sensation of non-existing odours. Causes: Functional. Organic. -Influenzal neuritis. -Epileptic aura. -Drugs: Streptomycin.

Investigations: Differential diagnosis Endoscopy CT

Endoscopic Nasal Examination Nasal Septum Inferior Turbinate

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