Bored by anatomy?
Try this.

• Learn faster
  and with more fun
• Ace your next exam
  with ease
• Get expert support
  from anatomy nerds

Trusted by 2,000,000+
students & professionals

Start Now

Last update: Dec 7th, 2017

Paranasal Sinuses

Learn anatomy faster and
remember everything you learn

Start Now

Introduction to the Paranasal Sinuses:

• The paranasal sinuses are cavities in the bones of the face and cranium.

1

2

• These air – filled spaces vary in size and are lined by mucous membrane.
• The mucous secretions drain into the nasal cavity and help, warm, humidify, and clean the air.
• The paranasal sinuses also help lighten the skull and resonate the voice.

Anterior View:

1. Frontal sinuses – two cavities located just above the orbits and behind the superciliary arches. [Anterior view]

1

2

3

• Mucous secretions are drained from each sinus by a frontonasal duct, which empties into the nasal cavity at the middle meatus.

Coronal View:

1. Ethmoid sinuses – a collection of small cavities located between the orbits in the lateral masses (or labyrinths) of the ethmoid bone. [Coronal view]

The coronal view of the ethmoid sinuses

1

2

3

• Each lateral mass contains approximately 6 to 12 cavities, which are referred to as ethmoid air cells.
• The mucous secretions produced by the air cells drain into the nasal cavity at the superior and middle meatuses.

Have you been making any of these common anatomy learning mistakes?

2. Maxillary sinuses – two large, cavities located in the body of the maxillary bone, on either side of the nasal cavity. [Coronal view]

The coronal view of the maxillary sinuses

1

2

3

• Mucous produced by each sinus drains into the mid-lateral wall of the nasal cavity.

Sagittal View:

1. Sphenoid sinuses – two cavities (right & left) in the centre (or body) of the sphenoid bone. [Sagittal view]

The sagittal view of the sphenoid sinuses

1

2

3

• A thin bony septum separates the two sinuses.
• Mucous from the sinuses drains into the spheno-ethmoidal recess located at the top of the nasal cavity.

2. Frontal sinuses – two cavities located just above the orbits and behind the superciliary arches. [Sagittal view]

The sagittal view of the frontal sinus

1

2

3

• Mucous secretions are drained from each sinus by a frontonasal duct, which empties into the nasal cavity at the middle meatus.

Test yourself:

Anterior view [Show/Hide answers]

Test yourself - anterior view

1

2

Test yourself:

Coronal view [Show/Hide answers]

Test yourself - coronal view

1

2

Test yourself:

Sagittal view [Show/Hide answers]

Test yourself - Sagittal view

1

2