Dilator naris anterior

The dilator naris anterior (Latin: musculus dilator naris anterior) is a muscle of facial expression that encircles the nostril and participates in widening it. It is classified as the nasal facial muscle.

Sometimes the dilator naris anterior and posterior are referred to as parts of the nasalis muscle. Together with the alar part of the nasalis, the dilator naris anterior may also function to prevent the collapse of the nasal valve during inspiration.

Dilator naris anterior, Nasal muscles, Facial muscles, Muscles of facial expression, Head muscles
Dilator naris anterior by Anatomy Next
Dilator naris anterior
Origin Upper lateral cartilage and alar part of nasalis
InsertionSkin at lower margin of lateral alar crus
ActionDilates nostril
InnervationBuccal branch of facial nerve (CN VII)
Blood supply Branches of facial artery

 

Origin

The dilator naris anterior originates from the upper lateral cartilage and alar portion of the nasalis muscle.

 

Insertion

The dilator naris anterior inserts into the skin of the nose at the lower margin of the lateral alar crus of the lower lateral (greater alar) cartilage.

Origin and insertion of dilator naris anterior
Origin and insertion of dilator naris anterior by Anatomy Next

 

Action

Upon contraction, the dilator naris anterior dilates the nostril.

Action of nasal dilator muscles
Action of nasal dilator muscles by Anatomy Next

 

Innervation

The dilator naris anterior muscle is innervated by the buccal branch of the facial nerve (CN VII).

 

Blood supply

The dilator naris anterior receives arterial blood supply from the branches of the facial artery.