ORBIT & OCULAR ADNEXAE - Paranasal Sinuses

Question 1

Which sinuses drain into…
1. the superior meatus
2. middle meatus
3. inferior meatus

Answer 1

1. superior - sphenoid and posterior ethmoid
2. middle - maxillary, anterior ethmoid, frontal
3. inferior - opening of nasolacrimal duct

Question 2

What is the route of the cavernous sinus?
1. Extends from the …. to the ….
2. Opens posteriorly into the ….
3. What structures are on the lateral wall?
4. What structure runs medially?
5. What structure runs in between?

Answer 2

1. Extends from SOF to apex of temporal bone
2. Opens posteriorly into petrosal sinuses
3. Lateral wall - CN 3, CN 4, CN V1, V2
4. Medially - internal carotid artery
5. In between - CN 6 (abducens)

Question 3

Which is the largest paranasal sinus?

Answer 3

Maxillary sinus

Question 4

What is the nerve supply of
1. Maxillary sinus (4)
2. Frontal sinus (1)
3. Sphenoid sinus (1)
4. Ethmoid sinus (3)

Answer 4

Maxillary: infraorbital, anterior/middle/ posterior superior alveolar nerves

Frontal: supraorbital nerve (ophthalmic)

Sphenoid: posterior ethmoidal nerve

Ethmoid: anterior and posterior ethmoidal nerves and pterygopalatine ganglion

Question 5

Which paranasla sinuses are present at birth (3)

Answer 5

1. ethmoid
2. maxillary
3. frontal (sometimes, usually at 2 years)

Question 6

Which paranasal sinuses develop 2-3 years after birth (2)

Answer 6

1. sphenoid
2. frontal (usually at 2 years, sometimes at birth)