Sinonasal Imaging Anatomy

Question 1

What is the bone of origin of the maxillary sinus?

Answer 1

Paired air cells in the maxillary bone

Question 2

What is the drainage of the maxillary sinus?

Answer 2

Maxillary sinus drainage is primarily via the maxillary ostium into the infundibulum, which in turn empties into the posterior aspect of the hiatus semilunar is of the middle meatus

Question 3

The ethmoid bone is consists of four parts. What are these parts?

Answer 3

The horizontal lamina, called the cribriform plate;
A perpendicular plate;
And two lateral masses, called the ethmoid labyrinths

Question 4

The roof of the ethmoid labyrinth is called ______.

Answer 4

Fovea ethmoidalis

Question 5

The number of ethmoid cells varies from how many?

Answer 5

3 to 18

Question 6

The thin, lateral wall separating the ethmoid air cells from the orbit is called the _______.

Answer 6

Lamina papyracea

Question 7

The roof of the ethmoid air cells (fovea ethmoidalis) also is the floor of the ______________.

Answer 7

Anterior cranial fossa

Question 8

Drainage of the ethmoid sinus

Answer 8

Anterior ethmoid air cells empty into the anterior aspect of the hiatus semilunaris

Middle ethmoid air cells empty through the ethmoid bulla into the middle meatus

Posterior ethmoid air cells empty into the superior meatus, then into the sphenoethmoidal recess

Question 9

These are defined as the anterio-inferior, most extramural ethmoid aircells.

The termed extramural is used, when the air cell is not confined within the parent bone (ethmoid cell)

Answer 9

Agger nasi air cells

Question 10

These are defined as the ethmoidal air ells extending along the medial floor of the orbit (infraorbital air cells).

Answer 10

Haller’s cells

Question 11

These are defined as the convex, inferomedial bony wall overlying the middle ethmoid air cells.

Answer 11

Ethmoid bulla (bulla ethmoidalis)

The ethmoid bulla protrudes inferomedially into the middle meatus

Question 12

What are walls of the sphenoid sinuses?

Answer 12

The roof of the sphenoid sinus is the sella turcica.

The anterior wall is shared with the ethmoid sinuses.

The posterior wall is the clivus.

The inferior wall is the roof of the nasopharynx.

Question 13

Where is the drainage of the sphenoid sinus?

Answer 13

The sphenoid sinuses drain into the sphenoethmoidal recess just posterior to the superior meatus

Question 14

What are the walls of the frontal sinuses?

Answer 14

The inferior wall of the frontal sinuses also is the anterior portion of the orbital roof.

The posterior wall directly abuts the anterior cranial fossa.

Question 15

What does the frontal sinuses drain?

Answer 15

The frontal sinuses drain via the nasofrontal duct through or adjacent to the anterior ethmoid air cells, then into the frontal recesses of the middle meatus of the nose

Question 16

Important components of the ostiomeatal unit includes:

Answer 16

Infundibulum
Uncinate process
Ethmoid bulla
Hiatus semilunaris
Middle meatus

Question 17

What foramen connects the lateral nasal cavity with the pteryopalatine fossa?

Answer 17

Sphenopalatine foramen

Question 18

This fossa is the major crossroads between the nasal cavity, nasapharyngeal mastication space (infratemporal fossa), orbit, and middle cranial fossa.

Answer 18

Pterygopalatine fossa