Nasalis

Musculus nasalis

Also known as: compressor naris, dilator naris

The main muscle of the nose. Its transverse part compresses the nostril and its alar part flares it.

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Overview

Nasalis arises from the maxilla just lateral to the nasal notch. Its transverse part (compressor naris) sweeps over the bridge of the nose and joins its partner over the nasal cartilages. Its alar part (dilator naris) attaches to the alar cartilage and widens the nostril. Flaring of the nostrils is a visible sign of respiratory distress, especially in infants.

Parts & subdivisions

Transverse part
Compresses the nasal aperture.
Alar part
Draws the ala laterally to dilate the nostril.

Anatomy

Origin: Maxilla, superior to the incisor and canine teeth, lateral to the nasal notch.
Insertion: Nasal aponeurosis over the bridge of the nose (transverse part) and the alar cartilage (alar part).
Action: Compresses (transverse part) or dilates (alar part) the anterior nasal aperture.
Innervation: Facial nerve (CN VII), buccal (and zygomatic) branches.
Nerve roots: Cranial nerve VII; no spinal roots
Arterial supply: Facial artery (superior labial and lateral nasal branches); dorsal nasal branch of the ophthalmic artery.

Function

Compresses or flares the nostrils

Clinical significance

Nasal flaring

Recruitment of the alar part during respiratory distress, such as in bronchiolitis or pneumonia in infants, is a sign of increased work of breathing.

Compiled from standard anatomy and physiology references — see the Muscular System sources. For education only; not medical advice.