Paranasal Sinuses Flashcards
What are the 2 areas of the nose?
- External nose
2. Nasal cavity
What separates the nasal cavity into left and right halves?
Nasal septum
What are the 5 main components of the external nose?
- Tip
- Bridge (connects tip to forehead)
- Nostrils
- Ala (bind nostrils laterally)
- Nasal septum (bind nostrils medially)
What 3 bones from the superior framework of the external nose?
- Nasal bone
- Frontal process of maxillae
- Nasal process of frontal bone
What 3 cartilages form the inferior framework of the external nose?
- Septal cartilage
- Lateral nasal cartilages
- Alar cartilages
What 2 bones form hard palate?
- Palatine process of the maxilla
2. Horizontal plate of the palatine bone
What is the function of the hard palate?
Separates the nasal cavity from the oral cavity
What 3 bones form the roof of the nasal cavity?
- Body of sphenoid
- Cribriform plate of ethmoid
- Frontal bone
What forms the floor of the nasal cavity?
Hard palate
What forms the anterior nasal septum?
Septal cartilage
What 2 bones form the posterior nasal septum?
- Perpendicular plate of ethmoid
2. Vomer
What are the 4 nerves which supply the external nose?
- Supratrochlear
- Infratrochlear
- External nasal
- Infraorbital
What are the 3 bony projections on the lateral wall of the nasal septum called?
- Superior conchae
- Middle conchae
- Inferior conchae
What is the space below each conchae called?
Meatus
What is the sphenoethmoidal recess?
Small area above the superior concha
What is Kiesselbach/Little’s area?
Area in anteroinferior part of cartilaginous portion of nasal septum
What is the importance of Little’s area?
Submucous anastomosis of vessels from external and internal carotid arteries
What 4 arteries form the anastomosis in Little’s area?
- Sphenopalatine artery
- Greater palatine artery
- Superior labial artery
- Anterior ethmoidal artery
What 3 arteries found in Little’s area are derived from the external carotid artery?
- Sphenopalatine artery
- Greater palatine artery
- Superior labial artery
Which of the arteries found in Little’s area is derived from the internal carotid artery?
Anterior ethmoidal artery
To what 2 lymph nodes does the lymph in the nose drain to?
- Submandibular lymph nodes
2. Upper deep cervical lymph nodes
Name 4 paranasal sinuses
- Frontal sinus
- Ethmoid sinuses
- Maxillary sinus
- Sphenoid sinus
What shape is the maxillary sinus?
Pyramidal shape
Where is the maxillary sinus located?
Within body of maxilla above alveolar arch, beneath the eyes and next to the nose
What forms the roof of the maxillary sinus?
Floor of the orbit
What is the nerve supply of the maxillary sinus?
Branches from the maxillary division of trigeminal
What is the floor of the maxillary sinus related to?
Roots of premolars and molar teeth are visible in floor
Where are the frontal sinuses located?
Within frontal bone
What shape are the frontal sinuses?
Triangular
Where do the sphenoidal sinuses lie?
Within the body of the sphenoid bone below sella turcica
Where are the ethmoid sinuses found?
Ethmoid bone between nose and orbit
What are the 3 ethmoid sinuses?
- Anterior
- Middle
- Posterior
What is the nerve supply of the frontal sinus?
Ophthalmic division of trigeminal
What is the nerve supply of the sphenoid sinus?
Ophthalmic division of trigeminal
What is the nerve supply of the ethmoid sinus?
Ophthalmic division of trigeminal
Where does the posterior ethmoidal sinus open?
Superior meatus
Where does the middle ethmoidal sinus open?
On or above bulla ethmoidalis of middle meatus
Where does the anterior ethmoidal sinus open?
Anterior end of hiatus semilunaris of middle meatus via infundibulum with frontal sinus
Where does the frontal sinus open?
Anterior end of hiatus semilunaris of middle meatus via infundibulum with anterior ethmoidal sinus
Where does the maxillary sinus open?
Hiatus semilunaris of middle meatus
What opens in the inferior meatus?
Nasolacrimal duct
Where does the sphenoid sinus open?
Sphenoethmoidal recess
What are the 2 areas of the middle meatus?
- Hiatus semilunaris
2. Bulla ethmoidalis
Describe the lymphatic drainage of paranasal sinus
- Submandibular LN
Frontal sinus
Maxillary sinus
Anterior and middle ethmoidal - Retropharyngeal LN
Posterior ethmoidal
Sphenoidal
Give 6 functions of the paranasal sinuses
- Heats air
- Moistens nose
- Traps particles
- Lessens weight of skull
- Strengthens skull
- Resonance chamber for voice
What is oroantral fistula?
Pathological communication between oral cavity and maxillary sinus
What 4 things can cause an oroantral fistula?
- Dental infections
- Osteomyelitis
- Radiation therapy
- Trauma
