Anatomy: Nasal Cavity Flashcards
Nerve supply to the skin of the external nose is?
- External nasal nerve (terminal part of the anterior ethmoidal nerve)
- Infratrochlear branch of the nasociliary nerve
- Nasal branches of the infraorbital nerve
What is the blood supply to the skin of the external nose?
- External nasal artery from the anterior ethmoidal artery
- Dorsal nasal artery (terminal branch of the opthalmic artery)
- Lateral nasal branch of facial artery
- Septal branches of superior labial branch
What are the anatomoses of the branches of the dorsal nasal artery?
- one branch anastomoses with the angular artery
- one branch anastomoses with its fellow artery on the opposite side and with the lateral nasal branch of external maxillary
Dorsal nasal artery is a branch of?
The dorsal nasal artery is the terminal branch of the opthalmic artery
Formation of lateral wall of nasal cavity
Formed by the:
- Maxilla
- Perpendicular plate of the palatine and medial pterygoid plate (which closes the defect in the maxilla)
- Labyrinth of the ethmoid bone, superior and middle conchae
- Inferior concha
Depression in front of the middle concha is called?
The atrium which leads into the meatus (found behind the atrium and under the concha)
What is the formation of the medial wall of the nasal cavity?
The nasal septum consisting of bone and cartilage represents the medial wall of the nasal cavity.
Bone:
Vomer and perpendicular plate of the ethmoid (which articulates with the upper margin of the vomer) forms the posterior border of the nasal septum.
Cartilage:
Septal cartilage forms the anterior-superior part of the septum and is frequently deviated from the midline.
Anterior-inferior part of the nasal septum is formed by the medial crura of both major alar cartilages - it is mobile
What forms the floor of the nasal cavity?
The upper surface of the hard palate
What comprises the hard palate?
The palatine process of the maxilla and the horizontal plate of the palatine bone
What forms the roof of the nasal cavity?
Centrally : cribriform plate of the ethmoid bone
Anteriorly: Nasal spine of the frontal bone and nasal bone
Posteriorly: Body of the sphenoid bone
What lies behind the superior concha?
The sphenoethmoidal recess which receives the osteium of the sphenoidal air sinus (opening of the sphnoidal sinus is present)
Which ridge bounds the atrium anterior-superiorly (depression in front of the middle concha)?
The agger nasi
Superior concha overlies which structure of the lateral wall of the nasal septum?
It overlies the superior meaturs into which drains the posterior ethmoidal air cells
Middle concha overlies which structure of the lateral wall of the nasal septum?
Overlies the middle meatus.
Contains:
- Ethmoidal bulla of the ethmoid bone - middle ethmoidal air cells
- Hiatus semi-lunaris, (which leads into the ethmoidal infundibulum)
- Anterior ethmoidal air cells which open into the ethmoidal infundibulum/frontonasal recess
- Maxillary sinus ostium ( usually on the lateral aspect of infundibulum between the middle and posterior third)
- Accessory ostium ( may be present anterior or posterior to lower part of the uncinate process)
What is the limen nasi>
A ridge found between the nasal vestibule and the nasal cavity proper
Where is the opening of the posterior ethmoidal air cells?
The superior meatus
Where is the opening of the middle and anterior air cells?
The middle meatus
List structures in the middle meatus
Ethmoidal bulla, Middle and anterior ethmoidal air cells, the opening of the frontonasal duct, semilunar hiatus, the opening of the maxillary sinus
List the structures in the inferior meatus
The opening of the nasolacrimal duct
What is the main artery supply of the nasal cavity?
The sphenopalatine branch of the maxillary artery
Makes sense because the lateral wall is made up of the maxilla!
What is the entry point of the sphenopalatine artery?
It enters the nose through the sphenopalatine foramen
Sphenopalatine artery is a branch of the…?
Maxillary artery
Spenopalatine artery supplies the…?
Mucosa over the cconchae and meatuses as well as the septum
Sphenopalatine artery anastomoses with…?
- Septal branch of the supeior labial artery (which enters through the nostrils)
- Ascending branch of the greater palatine artery –> Kiesselback’s plexus
What is the all the blood supply to the nasal cavity?
- Spehnopalatine branch of maxillary artery
2. Anterior and Posterior branches of the Opthami artery.
Where does the anterior and posterior opthalmic branches supply in the nose?
Enter the nose from the orbit and supplies the roof and upper parts of the lateral wall and septum
Venous drainage of the nasal cavity is…?
Pterygoid plexus, facial vein, opthalmic vein.
Rare (1%) emmissary vein which traverses foramen caecum and connect nasal veins to superior saggital sinus
Lymph drainage to nasal cavity..?
Lymph drains to the:
- submandibula
- Retropharyngeal
- Deep cervical nodes
What is nerve supply to the nasal cavity
- Olfactory nervers
- Infraorbital nerve
- Anterior ethmoidal nerve
- Anterior superior alveolar nerve
- Lateral posterior superior nasal branches of pterygopalatine ganglion
- Posterior inferior nasal branches of the greater palatine nerve
Nerves supplying septum…?
- Olfactory nerve in an upper part
- Anterior ethmoidal in the front
- Medial posterior superior nasal nerve at the back (including nasopalatine nerve)
Which area’s do the olfactory nerve supply?
Olfactory area (the roof of the nasal cavity), upper parts of the lateral wall, and septum
Which area’s do the infraorbital nerve supply in the nasal cavity?
The vestibular area
The respiratory area of the lateral nasal wall is supplied at the front by?
the anterior ethmoidal nerve
What supplies the lateral anterior inferior portion of the nasal cavity?
The anterior superior alvelolar nerve
What supplies the lateral posterior superior nasal cavity?
The posterior superior lateral nasal branch of maxillary nerve from the ptyergopalatine nerve
What supplies the lateral posterior inferior nasal cavity?
Posterior inferior lateral nasal branch of greater palatine nerve
What is the purpose of the paranasal sinuses?
It contributes to the warming and humidifying of inspired air
What lines the paranasal sinuses?
Respiratory Epithelium
It also contains glands to produce film of mucus
List the paranasal sinuses?
Maxillary, ethmoidal, frontal, sphenoidal
What are the relations of the maxillary sinus?
Roof: The floor of the orbit
Floor: Alveolar process of maxilla
Posterior wall: ptyergopalatine and infratemporal fossae
Anterior wall: Cheek
What is the shape of the maxillary sinus?
It is pyramidal shape. The apex being in the zygomatic process of maxilla. The base being the lateral wall of the nose.
What is the development of the maxillary sinus?
Present at birth but as a slit.
The size of the slit increases after puberty
The maxillary sinus opens up into the…?
The maxillary sinus opens into the posterior part of the infundibulum in the middle meatus
What is the blood supply to the maxillary sinus?
Small branches of facial, maxillary, infraorbital, greater palatine arteries.
Where is the ethmoidal sinus located?
Lies between the orbit and the nse in the ethmoidal labyrinth (lateral part of the ethmoid bone)
Ethmoidal labyrinth wall is paper thin (lamina papyracea)
How many ethmoidal cells are there?
There are between 3 to 18 ethmoidal cells. These cells are divided by bony septa.
What are the types of ethmoidal cells?
Anterior, middle and posterior ethmoidal cells. Each has its own ostium.
Describe the ethmoidal air cells
Anterior air cells - occupy the anterior part of the sinus, the ostia usually opens in the infundibulum (middle meatus) but sometimes in the frontonasal duct (which opens into the frontal sinus)
Middle air cells - drain into the middle meatus , they form the ethmoidal bulla
Posterior air cells - drain into the superior meatus
Relations of the sphenoidal sinus
Superior relation: the pituitary fossa and middle cranial fossa
Lateral relation: cavernous sinus and internal carotid artery
Posterior relation: Posterior cranial fossa and pons
Inferior relation: Roof of the nasopharynx
Where is the ostium of the sphenoidal sinus?
Ostium is located in the anterior wall od the sphenoidal sinus and opens into the sphenoethmoidal reces behind the superior concha
