Muscles of Face & Neck Flashcards
Anterior Belly Digastric
Innervated by Mylohyoid Nerve (branch of CN V3)
Anterior Inferior mandible –> fibrous loop above Hyoid bone. Form lateral boundaries of submental triangle of neck, medial boundaries of digastric (submandibular) triangle.
Elevates hyoid bone
Posterior Belly Digastric
Innervated by Facial Nerve
Posterior inferior mandible –> fibrous loop above Hyoid bone. Form posterior boundary of digastric (submandibular triangle). Form superior boundary of carotid triangles.
Elevates hyoid bone
Superior Belly Omohyoid
Innervated by Ansa Cervicalis (C1,2,3)
Hyoid –> Intermediate tendon (which is attached to clavicle & first rib). Forms medial boundary of carotid triangle. Forms lateral boundary of muscular triangle.
Depresses hyoid bone
Inferior Belly Omohyoid
Innervated by Ansa Cervicalis (C1,2,3)
Superior border of scapula –> intermediate tendon (which is attached to clavicle & first rib)
Depresses hyoid bone
Thyrohyoid
Innervated by nerve to thyrohyoid (C1) (piggybacks on CN12)
Thyroid cartilage –> hyoid bone
Depress hyoid bone/elevate thyroid cartilage
Geniohyoid
Innervated by nerve to geniohyoid (C1) (piggybacks on CN12)
Chin –> hyoid bone
Elevate hyoid bone/depress mandible
Splenius Capitus
Innervated by dorsal rami of C3 and C4
Spinous processes of C7-T3 –> Mastoid process of temporal bone. Superior portion of roof of posterior triangle of neck.
Head extension, lateral rotation and flexion of cervical spine.
Levator Scapulae
Innervated by Dorsal Scapular n.
Transverse processes of C1-4 –> medial border of scapula. Runs in floor of posterior triangle of neck, between Splenius Capitus & scalenes.
Elevates scapula.
Scalenes (posterior, middle, anterior)
Innervated by C3-C7
Transverse processes of cervical vertebrae –> first & second ribs.
Runs in floor of inferior portion of posterior triangle of neck.
Lift first & second ribs, laterally flex neck to same side.
Sternohyoid
Innervated by Ansa Cervicalis (C1-C3)
Sternum –> Hyoid
Depress Hyoid
Sternothyroid
Innervated by Ansa Cervicalis (C1-C3)
Sternum –> Thyroid cartilage
Depress thyroid cartilage, and indirectly depress hyoid.
Mylohyoid
Innervated by nerve to Mylohyoid (branch of CNV3)
Sheet like. Entire length of inner mandible –> Hyoid bone
Elevate Hyoid bone.
Stylohyoid & Digastric muscles are superficial to MH. Geniohyoid is deep to MH.
Stylohyoid
Innervated by Facial Nerve (CN7)
Styloid process of temporal bone –> Hyoid bone.
Anterior and Superficial to Post belly of digastric.
Elevate Hyoid bone.
Orbicularis oculi
CN7
Completely surrounds each orbit.
Orbital part- surrounding orbit and beyond rim. Closes eye forcefully.
Palpebral part. In eyelids. Originate medially, attach laterally. Close eye gently.
Corrugator supercilii
CN7
Deep to eyebrows.
Draws eyebrows down and medial, wrinkles skin above nose during frowning. >:(
Nasalis
CN7
Transverse part- on superior/lateral part of nose itself. Compresses nares.
Alart part. Inferior/lateral to nose. Depresses and pulls alar cartilage laterally- opens nares.
Procerus
CN7.
Goes from nasal bone superiorly to skin of forehead between the eyebrows.
Pulls skin between eyes down during frowning.
Depressor septi nasi
CN7
Originates in maxilla, inserts into nasal septum
Pulls nose inferiorly, widens nares
Depressor anguli oris
CN7
Inf margin of mandible–> corner of lip
Depresses corner of mouth (frowning)
Depressor labii inferioris
CN7
Lateral inf mandible –> center of lower lip
Depresses lower lip laterally.
Mentalis
CN7
Med inf mandible –> lower lip
Positions lip when drinking from a cup or pouting.
Risorius
CN7
Lat mandible –> corner of lip
Stretches lips laterally, grin.
Zygomaticus major/minor
CN7
Lateral part of zygomatic arch (cheekbone) –> corner of lip
Elevates corners of lip, smile
Levator labii superioris
CN7
Medial part of cheekbone to upper lip.
Deepens furrow between nose and mouth (pursing upper lip)
Levator labii superioris alaeque nasi
CN7
Lateral nasal bone to upper lip.
Flares nostrils.
Levator anguli oris
CN7
Upper mouth to corner of lip.
Elevates corner of mouth.
Orbicularis Oris
CN7
Surrounds mouth
Narrows mouth and closes lips.
Buccinator
CN7
Posterior maxilla and mandible –> orbicularis oris muscle.
Muscular component of cheek. Pressing cheeks against teeth, forcibly expelling air from cheeks.
Platysma
CN7
Subcutaneous fascia near clavicle –> orbicularis oris
Draws corners of mouth inferiorly, widens mouth. Draws skin of neck superiorly when teeth clenched.
Occipitofrontalis
CN7
Frontal belly on forehead (skin of eyebrows), Occipital belly on back of head (superior nuchal line, mastoid process of temp bone), epicranial aponeurosis connects 2 bellies by running on top of head (scalp).
Wrinkles forehead, moves scalp, raises eyebrows.
