Paranasal Sinus Anatomy: Structure, Boundaries, And Functions

Paranasal Sinus Anatomy: Structure, Boundaries, And Functions

Question 1. Give boundaries, relations & applied anatomy of sphenoidal air sinus
Answer:

• It is a paired sinus

Sphenoidal Air Sinus Boundaries:

• Anteriorly-Roof of the orbit
• Posteriorly- Anterior margin of foramen magnum
• Laterally- pterygoid canal

Sphenoidal Air Sinus Relations:

Sphenoidal Air Sinus Applied Anatomy:

• Infection of a sinus is known as sinusitis
• It causes headache & persistent, thick, purulent discharge from the nose
• It is diagnosed by transillumination & radiography
• A diseased sinus is opaque
• A surgical approach to pituitary gland is via sphenoidal sinus

Question 2. Paranasal air sinus
Answer:

They are air filled spaces present within some bones around the nasal cavities

Paranasal air sinus Types & Their Openings:

Paranasal air sinus Functions:

• Contained air of the sinuses adds humidity & temperature to the inspired air
• Serves as air-conditioning chambers
• Acts as resonating chambers for production of sounds
• Makes the facial bones lighter
• Establish adult contour of the face
• The mucous secretion of the sinuses is drained into the meatuses of the nose

Paranasal air sinus Growth:

• Rudimentary or absent- at birth
• Enlarges- during 6-7 years of age
• Next enlarges- due to

1. 1. Enlargement of bones in adults
   2. Resorption of the surrounding cancellous bone in old age