Question | Answer |
What is an air sinus? | A space in the bone lined by thin respiratory mucosa with a few goblet cells and glands |
What is the function of the paranasal sinuses? | 1) Resonance of the voice
2) Decrease the weight of the skull
3) Protection |
Change in voice indicates: | Sinusitis |
Describe the frontal air sinus: | It lies in the frontal bone of the skull and is triangular in shape |
Where does the frontal air sinus drain? | In the infundibulum at the level of the middle meatus |
The frontal air sinus is innervated by: | The supraorbital nerve which arises from the supraorbital foramen |
The Ethmoidal air sinuses are divided into: | Anterior, middle, and posterior ethmoidal cells |
The posterior drains into the: | Superior meatus |
The anterior and middle drain into the: | Middle meatus
Anterior --> semilunaris
Middle --> Bulla ethmoidalis |
Describe the maxillary air sinus: | Can be shown in x ray
Located at the maxilla and pyramidal in shape
Becomes larger with enlargement of facial bones
Apex directed laterally towards the zygomatic arch
Base on lateral wall of nose |
Maxillary air sinus drainage: | Bad venous drainage, because its opening is high up
Opens into the middle meatus |
Extraction of one molar tooth causes : | Fistula formation and drainage of the maxillary sinus |
How is this treated? | By an incision anterior to the lower part of the maxillary air sinus |
The maxillary air sinus is innervated by: | The infraorbital nerve and anterior superior alveolar branches from the maxillary nerve |
What are the relations of the maxillary air sinus? | Above: Orbital plate
Below: Upper molar teetn and premolars
Behind: Infratemporal fossa
Medial: Lower part of the nasal cavity |
Describe the sphenoid air sinus: | Located in the body of the sphenoid bone and above it, is the pituitary gland which lies in the sella turcica |
Where does the sphenoid air sinus drain? | The sphenoethmoidal recess |
A tumor in the pituitary gland can affect which sinus? | The sphenoid air sinus |
What is the innervation of the sphenoid air sinus? | Posterior ethmoidal branch of opthalmic
Orbital branches from the maxillary |
What are the relations of the sphenoid air sinus? | Above: The pituitary gland and optic chiasma
Laterally: The cavernous sinus which contains nerves (like the abducens nerve) and internal carotid artery
Below and in front: The nasal cavity |