What separates the anterior and posterior ethmoid air cells?

What separates the anterior and posterior ethmoid air cells?

Gross anatomy A collection of air cells (3-18 in number) separated by bony septa within each side of the lateral mass, or labyrinth, of the ethmoid bone. They are separated into anterior and posterior groups by the basal lamella, the lateral attachment of the middle turbinate to the lamina papyracea.

How does the sphenoid sinus drain?

The sphenoid sinus is divided by an intersinus septum as in the frontal sinus. The sphenoid sinus drains into the nose above the superior turbinate. The lateral wall of the sphenoid sinus contains the medial wall of the optic canal and the internal carotid artery.

What are sinus air cells?

The ethmoid air cells are numerous thin-walled cavities situated in the ethmoidal labyrinth and completed by the frontal, maxilla, lacrimal, sphenoidal, and palatine bones. They lie between the upper parts of the nasal cavities and the orbits, and are separated from these cavities by thin bony lamellae.

What are Agger nasi cells?

The agger nasi cell derives its name from the Latin phrase mean- ing “nasal mound.” Arising from the most superior remnant of the first ethmoturbinal, the pneuma- tized agger nasi is a prominence or bulge along the lateral nasal wall anterosuperior to the anterior at- tachment of the middle turbinate (figure, A).

What is Ethmoidal Bulla?

The ethmoid bulla (or ethmoidal bulla) is an elevation on the lateral wall of the middle meatus of the nose. It is produced by middle ethmoidal cells.

Where does the ethmoidal sinus drain into?

Ethmoid Sinuses They are located between the eyes, on either side of the septum. The anterior ethmoid cells drain into the ethmoid infundibulum, in the middle meatus. [22] The posterior ethmoid cells drain into the sphenoethmoidal recess located in the superior meatus.

What is the main function of the sphenoid sinuses?

Sinuses are air-filled sacs (empty spaces) on either side of the nasal cavity that filter and clean the air breathed through the nose and lighten the bones of the skull.

What is the ethmoid bulla?

The ethmoid bulla is the largest anterior ethmoid air cell. It is also one of the most consistent air cells in the middle meatus and is therefore a reliable anatomic landmark (Fig. 2.13). It often lacks a posterior wall, which is why it is not called a cell but rather a bony lamella with a large airspace behind it.

Where are the ethmoidal air cells located?

Ethmoidal air cells. The ethmoidal air cells, also known less commonly as the ethmoidal sinuses, form one of the four pairs of paranasal sinuses. They are located within the single, midline ethmoid bone.

What are Onodi air cells in sinus?

Interactive CT Sinus Anatomy | University of Washington. Onodi air cells represent contigous extension of the posterior ethmoid air cells into the sphenoid sinus and are closely associated with the optic nerve. Due to their close association with the optic nerve the nerve can be at increased risk of injury during sinus surgery.

What is the sphenoethmoidal recess of the nose?

The sphenoethmoidal recess is a small space in the nasal cavity into which the sphenoidal sinus and posterior ethmoid sinus open.

What are the differences between sphenoid sinus and pneumatization?

Sphenoid Sinus: Normal Anatomy & Variants The sphenoid sinuses are highly variable in their configuration. Pneumatization can extend into the greater sphenoid wing resulting in lateral recesses. Additionally, pneumatization can also involve the posterior orbital wall, pterygoid processes,…