The nose contains the external nose and nasal cavity. The nasal cavity contains paranasal sinuses including the maxillary, ethmoid, sphenoid, and frontal sinuses. The maxillary sinus is located within the maxilla bone and drains into the middle meatus. The ethmoid sinuses are divided by septa with multiple air cells that drain into the front of the nasal cavity. The sphenoid sinus is located in the sphenoid bone and drains into the sphenoethmoidal recess. The frontal sinus develops later and drains into the front of the nasal cavity. Together, the paranasal sinuses help warm, humidify, and cleanse air during breathing.

1. ANATOMY OF THE NOSE AND PARANASAL
SINUSES

2. OUTLINE
Introduction
Parts
External Nose
Nasal cavity
Paranasal sinuses

3. Introduction
The nose is for breathing; the design of its cavity results in warming
and moistening the inspired air, and in cleaning it too , Since odours
are airborne, the olfactory receptors are placed in the nose.

4. Parts
The nose consists of the external nose and the nasal
cavity, which is divided into right and left halves by
the midline nasal septum.

5. External Nose
The external nose projects from the face its skeleton is largely cartilaginous
The external nose consists of the nasal bones (the 'bridge' of the nose) and the lateral (upper) and
greater (alar or lower) nasal cartilages, supported in the midline by the cartilaginous part of the
nasal septum

6. Innervation
External nasal nerve ; tip of the nose
Infraorbital nerve: around the nostril
Blood supply
dorsal nasal artery
Lateral nasal artery
External nasal artery
Neurovascularization
The supratrochlear and infratrochlear nerves : lateral part

7. NASAL CAVITY
The nasal cavity extends from the nostrils (anterior nares) to the
posterior end of the nasal septum. Posteriorly it opens into the
nasopharynx through the posterior nasal apertures. It is divided into
two nares by the nasal septum.
Boundaries
Roof: It is divided into three parts (frontonasal, ethmoidal, and sphenoidal)
Floor: Palatine processes of the maxilla and the horizontal plates of the
palatine bone.
Medial wall: Nasal septum.
Lateral wall: The nasal conchae,

8. Features:

10.  Sphenoethmoidal recess
 Superior concha
 Superior meatus
 Middle concha
 Middle meatus
 Inferior concha
 Inferior meatus

11. sphenopalatine
Blood supply
Ascending branch of the greater
palatine
Septal branch of the superior labial
Little’s area
Anterior and posterior ethmoidal vessels supply
the roof and anterior part of the lateral wall.

12. Veins accompany the arteries and drain in various directions: to
the pterygoid plexus via the sphenopalatine foramen, to the
facial vein, to ophthalmic and inferior cerebral veins via the
ethmoidal foramina and
cribriform plate
Lymph drainage
Lymphatics tend to run with the veins rather than
arteries, and drain to submandibular, deep cervical and
retropharyngeal nodes.
Nerve supply
The olfactory area of the roof, superior concha and corresponding part of the
septum has the olfactory receptors and lhe cell bodies of the bipolar cells
embedded within the mucosa

13. The vestibular area is supplied by the infraorbital nerve whose branches
have 'crept in' from the face
The rest of the lateral wall, the respiratory area, is supplied as follows: at the front by the
anterior ethmoidal nerve in the upper part, and in the lower part by some filaments from
the anterior superior alveolar nerve; at the upper back part by the nasal branches from
the pterygopalatine ganglion and at me lower back part by the nasal branches of the
greater palatine nerve.
the septum is supplied by four nerves:
olfactory in the upper part, anterior ethmoidal at the
front, medial, posterior, and superior nasal nerve at
the back
the nasopalatine nerve

14. PARANASAL SINUSES
Maxillary sinus
The maxillary sinus is the space within the body of the
maxilla, known in earlier days as the maxillary antrurn
(of Highmore).
Boundaries
Roof: floor of the orbit
Floor: alveolar part of the maxilla, which is the roof of the mouth
Anterior and posterior walls are the corresponding walls of the maxilla
The maxillary sinus is present at birth, but is no more than a shallow slit, slightly
overgrown into a short cul-de-sac anteriorly and posteriorly.

15. The ostium of the sinus is high up and well back on
its nasal wall. It is 2-4 mm in diameter.
Blood supply. By small arteries that pierce the bone, mostly from the facial, maxillary,
infraorbital and greater palatine arteries, and veins accompany these vessels to the
facial vein and to the pterygoid plexus.
Lymph drainage. For the most part via the infraorbital foramen or the ostium; in either
case the lymphatics flow tothe submandibular nodes.
Nerve supply. By various branches of the maxillary nerve: superior alveolar (posterior,
middle and anterior), the greater palatine and infraorbital.

16. Each ethmoidal sinus lies between the orbit and the nose, in the ethmoidal labyrinth.
The sinus is not a single cavity) being divided by bony septum into a variable number
of ethmoidal air cells
There may be only 3 or as many as 18, each with their own ostium, and they are called
anterior, middle or posterior according to where they drain
Ethmoidal air cells
The anterior ethmoidal air cells occupy the anterior part of the sinus. Roofed in by the
frontal bone, the bony walls are completed by the lacrimal bone
. The ostia open into the anterior part of the semilunar hiatus in the middle meatus
The middle ethmoidal air cells also drain into the middle meatus.

17. At the back of the labyrinth the posterior ethmoidal air cells are completed by fusion of the orbital process of the
palatine bone and the sphenoidal concha. They are roofed in by the orbital pan of the frontal bone
The posterior air cells drain into me superior meatus
.
Nerve supply. By small branches from various nerves which include the supraorbital, anterior ethmoidal, lateral
posterior superior nasal, orbital and posterior ethmoidal nerves
Blood supply. By branches from the supraorbital, anterior and posterior ethmoidal and sphenopalatine
arteries
Lymph drainage. To submandibular and retropharyngeal nodes

18. The pair of sphenoidal sinuses occupy the body of the sphenoid bone. The two are separated by a
septum which is usually not in the midline, and they can vary greatly In size. When small
the sinus lies in front of the pituitary fossa
The ostium is in the anterior wall of the sinus and opens into
the sphenoethmoidal recess (behind the superior concha)
Lymph drainage. To retropharyngeal nodes.
Blood supply. From the posterior ethmoidal and sphenopalatine branches of the maxillary artery.
Nerve supply: The posterior ethmoidal nerve and the orbital branch of the pterygopalatine ganglion
maxillary nerve.
Sphenoidal sinus

19. The frontal sinuses are the only sinuses not present atbirth; they appear
during the second year as excavations into the diploe of the frontal bone,
and are really anterior ethmoidal air cells that have migrated upwards.
The sinus drains through an ostium at its lower medial corner into the
front end of the semilunar hiatus
Frontal sinus

20. Nerve supply. By the supraorbital and
supratrochlear nerves by branches that
pierce the frontal bone.
Blood supply. By supratrochlear, supraorbital and
anterior ethmoidal arteries. Venous drainage is into
diploic and superior ophthalmic veins.
Lymph drainage. Across the face to the
submandibular nodes