Agger nasi

Gray856

Agger nasi refers to a structure in the anatomy of the human nose. It is considered the most anterior part of the turbinates, which are long, narrow shelves of bone that project into the nasal cavity. The agger nasi is located in front of the middle turbinate, and it plays a crucial role in the drainage pathway of the frontal sinuses into the nasal cavity.

Anatomy

The agger nasi is a small ridge of bone that is found on the lateral wall of the nasal cavity, just anterior to the attachment of the middle turbinate. It is part of the ethmoid bone, one of the skull bones that contributes to the structure of the nasal cavity. The presence of the agger nasi creates a space known as the ethmoid infundibulum, which is a key pathway for the drainage of the frontal sinuses.

Function

The primary function of the agger nasi is related to the ventilation and drainage of the frontal sinuses. It helps to direct the flow of mucus and air from the frontal sinuses into the nasal cavity, thereby playing a vital role in the sinus's ability to function properly. Proper drainage of the sinuses is essential for preventing sinusitis, an inflammation of the sinuses that can lead to infection and blockage.

Clinical Significance

The agger nasi is of particular interest in endoscopic sinus surgery (ESS). Due to its location and relationship with the frontal sinus drainage pathway, understanding the anatomy of the agger nasi is crucial for surgeons performing ESS. Variations in the size and shape of the agger nasi can affect sinus drainage and are often addressed during surgery to improve sinus function.

In some cases, the agger nasi cells, which are air cells within the agger nasi, can become enlarged or diseased, leading to obstruction of the frontal sinus drainage pathway. This can contribute to chronic sinusitis and may require surgical intervention to resolve.

See Also

• Nasal cavity
• Sinusitis
• Endoscopic sinus surgery
• Ethmoid bone
• Turbinates