Atlas of Human Anatomy by Netter

(Darren Dugan) #1

GUIDE


Head and Neck: Nasal Region


Nasal region


External nose
Nasal cavities
Divided by nasal septum
Filter, humidify and warm air
Contain specialised olfactory mucosa
Receive secretions from paranasal sinuses and nasolacrimal duct
Includes related paranasal sinuses

External Nose
page 25
page 26


The nose is composed primarily of cartilages except at the "bridge" of the nose where the nasal bone resides. Anteriorly, the air enters or leaves the
nose via the nares, which open into the nasal vestibule, whereas posteriorly the nasal cavity communicates with the nasopharynx via paired
apertures called the choanae.


Composed of bone and hyaline cartilage Bones
Paired nasal bones
Frontal processes of maxilla
Nasal part frontal bone
Cartilages
Paired lateral cartilages
Paired alar cartilages
Septal cartilage
Associated muscles dilate and flatten nares (nostrils)
Nasalis
Compressor nares
Dilator nares
Innervation ophthalmic and maxillary divisions of trigeminal nerve (cranial nerve [CN] V 1 and V 2 )
Blood supply
Ophthalmic artery
Facial artery
Venous drainage
Facial veins → internal jugular veins
Ophthalmic veins → cavernous sinus

Nasal septum


The nasal cavity is separated from the cranial cavity by portions of the frontal, ethmoid, and sphenoid bones, and from the oral cavity inferiorly by the
hard palate. A nasal septum, usually deviated slightly to one side or the other, divides the nasal cavity into right and left chambers. The anterior third
of the nasal septum is cartilaginous and the posterior two thirds is bony.


Divides nasal cavity into two chambers
Composed of
Bone
Vomer
Perpendicular plate of ethmoid
Septal cartilage
Septal cartilage articulated with edges of bony septum

Nasal Cavity
page 26
page 27


The lateral wall of the nasal cavity is characterized by three shell-like conchae, or turbinates, that protrude into the cavity, and along with their
covering of nasal respiratory epithelium, they greatly increase the surface area for warming, humidifying, and filtering the air. At the most superior
aspect of the nasal cavity resides the olfactory region, with its olfactory epithelium and specialized sensory cells for the detection of smells.


Each cavity narrow above and wider below, separated from each other by nasal septum
Extend from nares to choanae
Naris = external opening of nose
Choana = opening into pharynx
Vestibule
First part of cavity
Lined with skin with hairs
Bounded laterally by alar cartilages
Limen nasi
Crescentic line
Marks upper limit of vestibule
Nasal mucosa
Lines nasal cavities except for vestibule
Bound to periosteum and perichondrium of surrounding bones and cartilages
Extends into all chambers, cavities and sinuses communicating with nasal cavities
Free download pdf