Nasalis Muscle, Anterior View

Description

Centered over the osseous nasal aperture, the nasalis muscle is rendered in anterior view with clear separation of its transverse part (compressor naris) and alar part (dilator naris). The transverse fibers sweep medially across the dorsum of the nose, bridging the right and left maxillary origins before blending into an aponeurosis over the nasal bones. Inferior and lateral to this, the alar part courses toward the alar cartilage and margin of the naris, positioned superficial to the lateral nasal cartilage region indicated in blue. Bony landmarks including the nasal bones, maxilla, and piriform aperture frame the muscle, with the orbits and dentition providing facial orientation and the cervical vertebrae extending inferiorly. Functionally, this is the key muscle for demonstrating dynamic control of the nasal valve and external nares, a point that often gets lost when the focus stays on deeper facial expression muscles. The transverse part narrows the nostrils by drawing the alae medially, while the alar part widens the nostrils, a pairing that becomes clinically relevant when assessing nasal airway obstruction, facial nerve dysfunction, or asymmetric alar collapse during inspiration. Surgical planning around rhinoplasty incisions and soft-tissue dissection benefits from recognizing how nasalis fibers cross the midline and relate to the upper lateral cartilages. Facial anatomy courses and ENT teaching sessions can use this plate to anchor surface action (nasal flaring) to named anatomy, and to distinguish muscular effects from structural causes of nasal obstruction. It also suits operative anatomy figures for rhinoplasty, cleft nasal deformity discussions, and exam-prep materials that test the relationship between the nasalis, nasal bones, and maxilla. Anatomical accuracy verified by SciePro's Medical Advisory Board.