{{Short description|Muscle of the nose}} {{Infobox muscle | Name = Nasalis muscle | Latin = musculus nasalis | Image = File:Sobo 1909 266.png | Caption = The superior transverse part and inferior alar part of the nasalis muscle | Image2 = | Caption2 = | Origin = Maxilla | Insertion = Nasal bone | Blood = Superior labial artery | Nerve = Buccal branch of the facial nerve | Action = Compresses bridge of nose, depresses tip of nose, elevates corners of nostrils | Antagonist = }} The '''nasalis muscle''' is a sphincter-like muscle of the nose. It has a transverse part and an alar part. It compresses the nasal cartilages, and can "flare" the nostrils. It can be used to test the facial nerve (VII), which supplies it.
== Structure == The nasalis muscle covers the nasal cartilages of the lower surface of the nose.<ref>{{cite book |doi=10.1016/B978-0-7020-3008-6.50010-7 |chapter=Small Superficial Defects — Secondary Intention Healing, Primary Repair, a Skin Graft or Local Flap |title=Nasal Reconstruction |date=2009 |last1=Menick |first1=Frederick J. |pages=65–90 |isbn=978-0-7020-3008-6 |oclc=460904328 }}</ref> It consists of two parts, ''transverse'' and ''alar'': * The ''transverse part'' ('''compressor naris muscle''') arises from the maxilla, above and lateral to the incisive fossa. Its fibers proceed upward and medially, expanding into a thin aponeurosis which is continuous on the bridge of the nose with that of the muscle of the opposite side, and with the aponeurosis of the procerus muscle. It compresses the nostrils and may completely close them.<ref name=":3">{{cite journal |last1=Attia |first1=Sarah A. |last2=Helal |first2=Hesham A. |last3=El Barabary |first3=Amir S. |last4=Awad |first4=Mostafa A. |last5=Sherif |first5=Mahmoud M. |title=Impact of nasalis muscle repair in unilateral cleft lip patients |journal=Journal of Cranio-Maxillofacial Surgery |date=February 2019 |volume=47 |issue=2 |pages=255–262 |doi=10.1016/j.jcms.2018.11.030 |pmid=30591393 }}</ref> * The ''alar part'' ('''dilator naris muscle''') arises from the maxilla over the lateral incisor and inserts into the greater alar cartilage. Its medial fibres tend to blend with the depressor septi nasi muscle, and has been described as part of that muscle.
=== Nerve supply === Like all the other muscles of facial expression, the nasalis muscle is supplied by the facial nerve (VII).<ref>{{Cite web|url=https://www.anatomynext.com/nasalis|title=Nasalis|website=www.anatomynext.com|language=en|access-date=2018-03-01|archive-date=2018-03-01|archive-url=https://web.archive.org/web/20180301225740/https://www.anatomynext.com/nasalis|url-status=dead}}</ref><ref name=":0">{{cite book |doi=10.1016/B978-1-4557-0308-1.00017-0 |chapter=Electrophysiologic Study of Disorders of Neuromuscular Transmission |title=Aminoff's Electrodiagnosis in Clinical Neurology |date=2012 |last1=Sanders |first1=Donald B. |pages=385–406 |isbn=978-1-4557-0308-1 |oclc=793587054 }}</ref>
== Function == The nasalis muscle compresses the nasal cartilages. It may also "flare" the nostrils.<ref name=":3" />
== Clinical significance ==
=== Cleft lip and cleft palate === The nasalis muscle is one of the key muscles not formed or inserted correctly with cleft lip and cleft palate deformity.<ref name=":1">{{cite book |doi=10.1016/B978-0-7020-6056-4.00067-8 |chapter=Techniques for Cleft Lip Repair |title=Maxillofacial Surgery |date=2017 |last1=Drake |first1=David |last2=Colbert |first2=Serryth |pages=948–971 |isbn=978-0-7020-6056-4 |oclc=968339962 }}</ref> The head of the transverse part needs to be identified during reconstructive surgery so that it can be surgically sutured (connected) to the nasal septum.<ref name=":3" /><ref name=":1" /> The origin at the maxilla may also be repositioned for better symmetry.<ref name=":3" />
=== Facial nerve testing === Due to it being superficial, the nasalis muscle can be used to test the facial nerve.<ref name=":0" /><ref name=":2">{{cite book |doi=10.1016/B978-1-4557-2672-1.00025-8 |chapter=Facial and Trigeminal Neuropathy |title=Electromyography and Neuromuscular Disorders |date=2013 |last1=Preston |first1=David C. |last2=Shapiro |first2=Barbara E. |pages=372–383 |isbn=978-1-4557-2672-1 |oclc=821857515 }}</ref> Specifically, it can be used to test the zygomatic branches.<ref name=":2" />
==Additional images== <gallery> Nasalis.png|Muscles of the head, face, and neck. (Nasalis labeled at center left.) File:Nasalis muscle animation small.gif|Position of nasalis muscle (shown in red). </gallery>
==References== <references/>
==External links== *[http://www.ivy-rose.co.uk/References/glossary_entry144.htm Interactive diagram at ivy-rose.co.uk]
{{Muscles of head}} {{Authority control}}
Category:Muscles of the head and neck Category:Facial muscles Category:Human head and neck