The Nose

The Nose

د. باسل محمد نذير سعيد / استاذ جراحة الاذن والانف والحنجرة
فرع الجراحة / كلية طب الموصل

Lecture 1

Anatomy of the Nose

1: External nose:

It is a projecting triangular pyramid directed downwards. It has apex, root connected to the forehead and base perforated by two nostrils.
Bones and Cartilages of the nose:
Nasal bones.
Maxillae.
Frontal bone (nasal process).
Upper lateral cartilages.
Lower lateral cartilages.
Septal cartilage.


The muscles of the nose are a part of facial muscles and are supplied with facial nerve.
See figure 1.

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Fig.1: Anatomy of the external nose.

2: Nasal Cavity

A-Nasal Vestibule
It is the entrance to the nasal cavity, lined with skin which is hair bearing.
B-Nasal cavity proper
They are two cavities separated by the nasal septum, extending from the anterior nares to the nasopharynx.
The mucosa of the nose is Ciliated Columnar Epithelium with olfactory epithelium at the roof.

The nasal septum (Medial Wall of the nasal cavity) is composed of the following:

1-Quadrilateral Cartilage ((Septal Cartilage)).
2-Perpendicular Plate of the Ethmoid bone.
3-The Vomer bone.
4-Nasal Crests of the Maxilla and the Palatine bones.

The Lateral Wall

The Inferior Turbinate: is a separate bone attached to the maxilla.
The Middle Turbinate.
The Superior Turbinate.


The middle and Superior turbinates are parts of the ethmoid bone
Bellow the inferior turbinate is the inferior meatus which receives the nasolacrimal duct opening. The middle meatus lies bellow the middle turbinate and receives the openings of the maxillary, frontal and the anterior ethmoidal sinuses. While the superior meatus receives the opening of the posterior ethmoidal cells. Above the superior turbinate is the Sphenoethmoidal Recess which receives the sphenoid sinus ostium.
The Roof of the nose is formed from anterior to posterior from: the nasal bones, the cribriform plate of the ethmoid bone and sphenoid bone.
The olfactory cleft area is lined with olfactory epithelium (special sensory epithelium) and occupies the area of the cribriform plate, the superior turbinate and the corresponding area of the septum.
The floor is formed of the maxilla and the palatine bones.
See figures 3,4 and5.

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Fig. 2,3,4 &5.

The Blood Supply

The external nose is supplied by branches of the facial, the maxillary and the ophthalmic arteries. The venous drainage is through the facial, maxillary and the ophthalmic veins, the latter drains to the cavernous sinus.
The blood supply to the nasal cavity is coming from the maxillary, facial, the anterior and the posterior ethmoidal arteries.
Little's area is the anteroinferior part of the nasal septum where anastomosis of vessels called Kiesselbach's plexus is located and is the commonest site of bleeding.
See figures 6,7&8.
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 Figures 6,7&8.

Nerve supply

The sensory innervations of the nose is supplied by the trigeminal nerve, mainly through the maxillary and the ophthalmic divisions.
The olfactory area is supplied by the olfactory nerve.
The nose also has sympathetic supply from the upper deep cervical ganglion. The parasympathetic supply comes from the geniculate ganglion of the facial nerve.

THE PARANASAL SINUSES

They are Air Filled cavities within the bones surrounding the nose and have openings or ducts draining into the nose. They are arranged in pairs and lined with respiratory mucus membrane. They comprise the maxillary, the frontal, the ethmoid and the sphenoid sinuses.

The Maxillary Sinus

This is the largest Para nasal sinus; it occupies the body of the Maxilla. It is also called the ANTRUM. It has a roof which is the floor of the orbit, a base or the medial wall, a floor which is the alveolar process of the maxilla and an apex.
The ostium is situated high on the medial wall and it opens into the middle meatus, so the drainage is dependant on the ciliary action of the mucosa, not on gravity.

The Frontal Sinuses

They are situated in the frontal bone and are divided into two parts by a septum.
The frontonasal duct of each sinus opens into the middle meatus.

The Ethmoid Sinuses

They are situated in between the nasal cavity medially and the orbit laterally where a very thin bone (lamina papyraceae) separates it from the orbit, superiorly the sinuses are bounded by the cranial cavity.
The sinuses are divided into two groups, an anterior group which drains into the middle meatus and posterior group which drains into the superior meatus.


The Sphenoid Sinuses
These occupy the body of the sphenoid bone and are divided by a septum into two, each sinus drains into the sphenoethmoidal recess.
See figures 9,10,11 & 12.

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Figures 9,10,11 &12.

The Physiology of the Nose

The nose has many functions
1-It is an airway passage which moistens and heats the inspired air due to high vascularity of the mucus membrane which is ciliated columnar epithelium.
2-The mucus is transported by the action of the cilia and contains antibodies which act as a defense mechanism.
3-It filters the inspired air from foreign bodies.
4-It adds resonance to sound.
5-Olfaction, the sense of smell.

Symptoms and Signs of Nasal diseases

Nasal block
Nasal discharge ((Rhinorrhoea)) and postnasal drip
Bleeding from the nose ((Epistaxis))
Sneezing and itching
Nasal pain, facial pain and headache
External deformity
Disorders of smell
Anosmia (total loss of the sense of smell)...Hyposmia (decreased the sense of smell)Hyperosmia (increased sense of smell)Cacosmia (perception of bad smell)
Signs like external deformity, scars, masses and other skin lesions are readily seen by simple examination.
Examination of the nose is done by using Nasal Speculum and Good light. This is Called Anterior Rhinoscopy. See fig.13.
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Deviated nasal septum, abnormality of the mucosa, bleeding vessels, and character of the secretions, nasal masses and polyps.
Postnasal examination is done by Nasopharyngeal Mirror. This is called Posterior Rhinoscopy.
ENDOSCOPIC EXAMINATION OF THE NOSE IS POSSIBLE BY USING FLEXIBLE AND RIGID ENDOSCOPES.

Investigations of the nose (Some of them)

X-ray paranasal sinuses
CT scan
MRI scan
Skin prick test for allergy.










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