OIIAN Unit 2

Innervation of Orbicularis Oculi musle

Temporal and zygomatic branches of facial nerve, CN VII

Action of Orbicularis Oculi musle

Palpebral part - gently closes eye; Orbital part - forcefully closes eye

Innervation of Corrugator supercilii

Temporal branch of facial nerve, CN VII

Action of Corrugator supercilii

Draws the eyebrows medially and downward; “worried look” (produces vertical wrinkles above nose)

Innervation of Nasalis muscle

Buccal branch of facial nerve, CN VII

Action of Nasalis muscle

Transverse portion - compresses bridge of nose; Alar portion – draws cartilage downward and laterally, opening nostril

Innervation of Depressor septi

Buccal branch of facial nerve, CN VII

Action of Depressor septi muscle

Pull nose inferiorly; acts to widen nostrils

Innervation of Procerus muscle

Temporal and zygomatic branches of facial nerve, CN VII

Action of Procerus muscle

Draws medial angles of eyebrows down producing transverse wrinkles over bridge of nose

Innervation of Orbicularis oris muscle

Buccal and marginal mandibular branches of facial nerve, CN VII

Action of Orbicularis oris

Closes and protrudes lips

Innervation of Buccinator muscle

Buccal branches of facial nerve, CN VII

Action of Buccinator muscle

Compresses cheek against teeth; compresses distended cheeks; keeps food between teeth; used during whistling or blowing a trumpet to force air forward out of mouth

Innervation of Depressor anguli oris muscle

Buccal and marginal mandibular branches of facial nerve, CN VII

Action of Depressor anguli oris muscle

Draws corner of mouth downward and laterally as in frowning

Innervation of Depressor labii inferioris muscle

Marginal mandibular branch of facial nerve, CN VII

Action of Depressor labii inferioris muscle

Draws lower lip downward and laterally

Innervation of Mentalis muscle

Marginal mandibular branch of facial nerve, CN VII

Action of Mentalis muscle

Raises and protrudes lower lip as it wrinkles the skin of the chin

Innervation of Platysma muscle

Cervical branch of facial nerve, CN VII

Action of Platysma muscle

Tenses the skin of the neck; can move the lower lip and corners of the mouth down

Innervation of the Risorius muscle

Buccal branch of facial nerve, CN VII

Action of the Risorius muscle

Retracts corner of the mouth; produces a "grin"

Innervation of the Zygomatic major muscle

Zygomatic and buccal branches of facial nerve, CN VII

Action of the Zygomatic major muscle

Draws corners of mouth upward and laterally; bilateral contraction = smiling; unilateral contraction = sneer)

Innervation of Zygomatic minor muscle

Zygomatic and buccal branches of facial nerve, CN VII

Action of Zygomatic minor muscle

Draws upper lip upward

Innervation of the Levator labii superioris muscle

Zygomatic and buccal branches of facial nerve, CN VII

Action of the Levator labii superioris muscle

Raises upper lip; helps form nasolabial furrow

Innervation of the Levator labii superioris alaeque nasi muscle

Zygomatic and buccal branches of facial nerve, CN VII

Action of the Levator labii superioris alaeque nasi muscle

Raises upper lip and opens nostril; forms a snarl (Elvis muscle)

Innervation of the Levator anguli oris muscle

Zygomatic and buccal branches of facial nerve, CN VII

Action of the Levator anguli oris muscle

Raises corner of mouth; helps form nasolabial furrow

Innervation of the Superior auricle muscle

Temporal branch of facial nerve, CN VII

Action of the Superior auricle muscle

Elevates the ear

Innervation of the Anterior auricle muscle

Temporal branch of facial nerve, CN VII

Action of the Anterior auricle muscle

Draws ear forward and upward

Innervation of the Posterior auricle muscle

Posterior auricular branch of facial nerve, CN VII

Action of the Posterior auricle muscle

Draws ear posteriorly and upward

Innervation of the Occipitofrontalis muscle

Occipital - Posterior auricular branch of facial nerve (CN VII) ; FrontalTemporal branch of facial nerve (CN VII)

Action of the Occipitofrontalis

Occipitalis: draws back scalp; Frontalis: wrinkles forehead, raises eyebrows

Origin of the Temporalis muscle

Temporal fossa and temporal fascia

Insertion of the Temporalis muscle

Coronoid process of mandible via a tendon that passes deep to the zygomatic arch; and anterior margin of ramus

Innervation of the Temporalis muscle

Mandibular nerve (CN V3)

Action of the Temporalis muscle

Elevates and retracts mandible, assists in side to side movement of mandible

Origin of the Masseter muscle

Superficial head- Zygomatic process of maxilla and zygomatic arch; Deep headMedial and inferior surfaces of zygomatic arch

Insertion of the Masseter muscle

Angle and ramus of the mandible

Innervation of the Masseter muscle

Mandibular nerve (CN V3)

Action of the Masseter muscle

Elevates mandible; superficial fibers assist with protrusion; deep fibers assist with retraction

Origin of the Lateral pterygoid muscle

Superior head- - greater wing of sphenoid bone; Inferior head- - lateral surface of lateral pterygoid plate of sphenoid

Insertion of the Lateral pterygoid muscle

Anterior TMJ capsule and disc; mandibular condyle

Innervation of the Lateral pterygoid muscle

Mandibular nerve (CN V3)

Action of the Lateral pterygoid muscle

Protrudes, depresses and moves mandible from side to side

Origin of the Medial pterygoid muscle

Deep head - Medial surface of lateral pterygoid plate of sphenoid and palatine bone; Superficial head - Tuberosity of the maxilla

Insertion of the Medial pterygoid muscle

Medial surface of ramus near angle of the mandible

Innervation of the Medial pterygoid muscle

Mandibular nerve (CN V3)

Action of the Medial pterygoid muscle

Synergistic with temporalis and masseter in elevation of mandible; Protrusion and side to side movements of the mandible

Origin of Stylohyoid muscle

Styloid process

Insertion of Stylohyoid muscle

Hyoid bone

Innervation of Stylohyoid muscle

Cervical branch, facial nerve, CN VII

Action of Stylohyoid muscle

Elevates and retracts hyoid, elongating floor of mouth during swallowing

Origin of the Digastric muscle

Posterior belly - mastoid notch of temporal bone; Anterior belly - digastric fossa on mandible

Insertion of Digastric muscle

Hyoid bone through fibrous, tendinous loop

Innervation of Digastric muscle

Posterior belly - Cervical branch of facial nerve, CN VII; Anterior belly, mandibular nerve (V3)

Action of the Digastric muscle

Elevates and steadies hyoid bone during swallowing and speech; if hyoid is fixed, helps depress the mandible and open the mouth

Origin of the Mylohyoid muscle

Mylohyoid line of the mandible

Insertion of the Mylohyoid muscle

Hyoid bone and median raphe

Innervation of the Mylohyoid muscle

Mandibular nerve, V3

Action of the Mylohyoid muscle

Elevates hyoid bone and floor of mouth; together with opposite side, forms floor of mouth

Origin of the Geniohyoid muscle

Mental spine on mandible

Insertion of the Geniohyoid muscle

Hyoid bone

Innervation of the Geniohyoid muscle

C1 spinal nerve anterior ramus

Action of the Geniohyoid muscle

Pulls hyoid superior and anterior, shortening floor of the mouth; pulls mandible downwards and inwards when hyoid bone is fixed

Origin of the Omohyoid muscle

Inferior belly - superior border of scapula; superior belly - tendon of inferior belly near sternocleidomastoid

Insertion of the Omohyoid muscle

Inferior belly - ends as tendon held to clavicle by central tendon; superior belly - hyoid bone

Innervation of the Omohyoid muscle

Ansa cervicalis (C1-C3)

Action of the Omohyoid muscle

Depresses and retracts hyoid bone

Origin of the Sternothyroid muscle

Manubrium of sternum

Insertion of the Sternothyroid muscle

Thyroid cartilage

Innervation of the Sternothyroid muscle

Ansa cervicalis (C1-C3)

Action of the Sternothyroid muscle

Depresses larynx

Origin of the Thyrohyoid muscle

Thyroid cartilage

Insertion of the Thyrohyoid muscle

Hyoid bone

Innervation of the Thyrohyoid muscle

C1 spinal nerve anterior ramus

Action of the Thyrohyoid muscle

Depresses hyoid; elevates larynx if hyoid is fixed

Origin of the Sternohyoid muscle

Manubrium of sternum; posterior to sternoclavicular joint

Insertion of the Sternohyoid muscle

Hyoid bone

Innervation of the Sternohyoid muscle

Ansa cervicalis (C1-C3)

Action of the Sternohyoid muscle

Depresses hyoid bone after swallowing

Origin of the Sternocleidomastoid muscle

Sternal head - manubrium of sternum; Clavicular head - medial third of clavicle

Insertion of the Sternocleidomastoid muscle

Mastoid process of temporal bone; lateral half of superior nuchal line

Innervation of the Sternocleidomastoid muscle

Accessory nerve, CN XI

Action of the Sternocleidomastoid muscle

Unilateral contraction - lateral flexion to same side, rotation to opposite side; bilateral contraction - neck flexion; with head fixed, assists with elevation of thorax during forced inspiration

Origin of the Longus capitis muscle

Anterior surface, transverse processes C3-C6

Insertion of the Longus capitis muscle

Occipital bone (anterior to foramen magnum)

Innervation of the Longus capitis muscle

Anterior rami C1-C3

Action of the Longus capitis muscle

Flexes cervical vertebrae and head

Origin of the Longus colli muscle

Superior oblique part - anterior surface of transverse processes C3- C5; vertical part - anterior bodies of C5-T3; inferior oblique part - anterior bodies of T1-T3

Insertion of the Longus colli muscle

Superior oblique part - anterior arch of atlas; vertical part - anterior surface vertebral bodies C2-C4; inferior oblique part - anterior surface of transverse processes C5-C6