Nasalis Muscle, Lateral View

Description

Running over the lateral nasal wall, the nasalis muscle forms a thin sheet superficial to the nasal cartilages, with the transverse part (compressor naris) spanning across the dorsum and the alar part coursing inferiorly toward the ala. Anterior to it sit the nasal bones and the frontal process of the maxilla, while posteriorly the muscle relates to the nasofacial groove and the soft tissue over the piriform aperture. Superiorly, fibers blend toward the aponeurotic region near the bridge of the nose, and inferiorly they approach the margin of the nostril and the alar cartilage. Bone landmarks remain readable beneath the soft tissues, including the frontal, parietal, and occipital bones with sutural detail, the zygomatic arch, and the maxilla with dentition in side profile. Lateral orientation matters for nasalis because its action is easiest to teach and clinically infer when you can track fiber direction relative to the nostril rim and the nasal dorsum. Compression of the nasal aperture by the transverse part can worsen subjective nasal obstruction when combined with septal deviation or turbinate hypertrophy, and it is a common target when discussing external nasal valve mechanics. Surgeons also consider this plane when planning rhinoplasty incisions and soft tissue elevation, since disruption of the nasalis and adjacent fibromuscular layers influences tip dynamics and alar contour. Small muscle, visible consequences. Use this asset for head and neck anatomy courses covering muscles of facial expression, for ENT or plastic surgery teaching files explaining functional nasal airflow, or for textbooks that need a clear lateral correlation between the nasalis and the underlying bony framework and upper cervical spine posture. Anatomical accuracy verified by SciePro's Medical Advisory Board.