anatomy of The nose

THE NOSE

Nose

-Extend from external nostril to posterior nasal a perture.

External nose-:

-pyramidal in shape

-it has root continous with forehead , and apex which is its free edge.

-lateral surface of nose called dorsum nasi, which end below in rounded a la nasi.

-external nose compose of : - Bones

- Hyline cartilage

Bonny part: - Nasal bone

- Frontal process of maxilla - Nasal part of frontal bone

Cartilaginous part: - Septal cartilage.

- Lateral nasal cartilage.

- Major alar cartilage. - minor alar cartilage.

Artery of nose: -Facial a. : - septal , alar branches .

-Ophthmalic a. :- dorsal nasal branches

-Maxillary a. :- infraorbital branches

** Never of muscles of nose is from facial nerve , skin from ophthmalic never through infra trachea, external nasal nerve , and from maxillary nerve through infra orbit nerve.

** Skin extend into vestibule within nostrils which contain stiff hairs .

Nasal cavity - :

- divided into RT, LT by nasal septam.

- two halves open on face through nostril communicated behind through neesopharynx through posterior nasal aperture (called choana).

-It has : 1. floor

2.roof

3.lateral wall

4.medial (septal) wall

-it has 3 region : 1. vestibula

2 .olfactory

3 .respiratory

Nasal vestibule -: - dilation inside aperture of nostril

- bounded laterally by alar, and lower nasal cartilage. - lined with skin, coarse hair and sebaceous gland ,

sweet gland. - limited above and behind by curved elevation called

limen nasi. Olfactory region-:

limited to superior nasal concha opposite part of septem , interventing roof. Present in roof , less vascular and appear yellow in color.Respiratory region:

The rest of cavity , very vascular red in color to warm the air.

Lateral wall-: - it is irregular due to presence of 3 bonny projection:

1 .inferior concha. 2.middle concha.

3.superior concha. -it is formed from:

1 -medial surface of maxilla.2 -ethmoid bone : - superior concha

- middle concha 3 -inferior concha.

4 -lacrimal bone.5 -perpendicular plate of palatine.

6 -medial pterygoid plate.

-Below and lateral to bonny elevation (conchar) is meatus. Above superior conchar is sphenoethmaidel recess which include opening of sphenoid air sinus.

-Some time 4th or highest nasal conchar at lateral wall of sphenoethmaidal recess with supreme nasal meatus which contain opening of posterior ethmoidal sinus.

Superior meatus and concha-: -it is shortest , shallowest of 3 meatus.

-behind superior meatus is sphenopalatine from a men which open into ptergo palatine fossa.

Middle concha and meatus-: -much larger articulated with perpendicular plate of palatine bone.

-at its upper part occupy by elevation called bulla ethmaidal which contain middle ethmaidal air cells. The opening of maxillary sinus is situated below bulla ethmaidal near the

posterior end of hiatus semilunaris .

-hiatus semilunaris which leads upward and fore ward into curved chaunel called ethmaidal infundibalam , in which anterior ethmaid sinus open in infundibalam .frontal sinus open through infundibalam into anterior end of hiatus semilunaris.

Inferior conchar-: -articulate with nasal surface of maxilla.

-extend to floor of nasal cavity. -it is largest of 3 meatus.

-naso lacrimal duct open drainexcess tear from eye. Duct open 2cm . behind nostril.

Nerve supply of lateral wall-: 1 -anterior superior by anterior ethmaidal n.

2 -anterior inferior by anterior superior alveolar. 3 -posterior superior by posterior lateral nasal nerve

branch of maxilla nerve . 4 -posretior inferior by greater palatine nerve.

Roof -:1 -frontal bone.

2 -ethmaid bone.3 -sphenoid bone.

-Horizontal part : - cribriform plate of ethmaid bone. -Anterior sloping part : 1- nasal spine of frontal bone

2 -nasal bone 3 -nasal cartilage

-Posterior sloping part : - body of sphenoid and on each sphenoid sinus .

-Nerve supply : - by 1st cranial nerve ( i.e. the olfactory nerve). -Blood supply : - anterior and posterior ethmaided arteies.

Floor-: - palatine process of maxilla.

- horizontal plate of palatine bone nerve supply by long sphenopalatine nerve and anterior ethmaidal nerve .

Medial wall (nasal septum)-: -Extend between roof and floor.

-Formed by : - 2 bones - cartilage

1 -Vomer :- extend from inferior surface of sphenoid bone.2-Prependicular plate of ethmaid which continuous above with

cribriform plate of ethmaid .3 -Septal cartilage is in between two bone.

** septal cartilage grooved on each side by long sphenopalatine vessels.

Nerve supply of nasal septum: Anterior superior part by anterior ethmaid nerve Posterior inferior part by sphenopalatine nerve.

Venous drainage of nasal mucosa-:

-form rich venous network or plexus in nasal mucosa especially in inferior part of septum.

-some of vein open into sphenopalatine vien and drain to pterygoid venous plexus.

-other join the facial vein and some empty into ophthmlic vein and drain into cavernous

sinus .

The Para nasal sinusesReasons for presence of these sinuses -:

-make skull lighter -help the resonance of voice

Development of sinuses-: -develop after birth as diverticular from nasal cavity.

-fully developed until puberty. -fined by ciliated columnar mucous epithelium.

Frontal sinuses-: -above orbit.

-variable in size. -usually asymmetrical.

-open into middle meatus. -related to anterior cranial fossa posteriorly.

-orbital , nasal cavities related inferiorly to sinus. -innervated by supra orbital ,and supratrchlar nerve.

Ethmoidal sinus or air cells-: -These are numerous spaces located within the

labyrinth of ethmoid bone. -They are 3 groups of air cells, according to location ,

Anterior ethmoidal sinus :- hiatus semilunaris. Middle ethmoidal sinus :- bulla-ethmoid

Posterior ethmoidal sinus:- superior meatus.Innervation-:

-Anterior ethmoidal -: } anterior ethmoidal nerve.

Middle ethmoidal Posterior ethmoidal :- posterior ethmoidal nerve.-

Sphenoidal air sinus-: -lies within the body of sphenoid.

-two in number , unequal in size separated from each other by an irregular septum .

-related to pituitary fossa superiorly and middle cranial fossa laterally. -innervated by posterior ethmoidal nerve.

-open into sphenoethmoidal recess , which located above superior conchar. Maxillary sinus-:

-largest of all paranasal sinus. -cone-shaped , located within body of maxilla

-it has-:Roof :- formed by orbital surface of maxilla.Floor:- formed by alveolar process of maxilla.Base:- formed by medial surface of maxilla.Lateral wall:- formed by lateral surface of maxilla.Posterior wall:- formed by posterior surface of maxilla.

Cavities :- related to the sinus are 1 -orbit :- roof2 -nasal cavity :- base

3 -infratemporal and sphenopalatine fossa :- posterior wall of sinus.

4 -canine fossa :- anterior wall of sinus.Innervation-:

Roof :- infraorbital nerve.Base :- anterior ethmoidal nerve.Posterior wall :- posterior superior dental nerve.Floor :- greater palatine nerve.Lateral wall :- anterior superior dental nerve.

** Blood supply is corresponding to nerve , but venous drainage is to pterygoid venous plexus .

** It open to hiatus semilunaris , middle meatus of nose but unfortunately the opening as at the top of sinus .

THE END