ES 553- head and face muscles (AOIN)

sternocleidomastoid

anterior scalene

middle scalene

posterior scalene

masseter

temporalis

digastric

suprahyoids

occipitofrontalis

lateral pterygoid

medial pterygoid

sternocleidomastoid origin and insertion

sternal head- O: top of manubrium

clavicular head- O: medial 1/3 of clavicle

I: mastoid process of temporal bone, the lateral portion of superior nuchal line of occiput

anterior scalene origin and insertion

O: transverse processes of C3-C6 (anterior tubercles)

I: first rib

middle scalene origin and insertion

O: transverse processes of C2-C7 (posterior tubercles)

I: first rib

posterior scalene origin and insertion

O: transverse processes of C6-C7 (posterior tubercles)

I: second rib

masseter origin and insertion

O: zygomatic arch

I: angle and ramus of mandible

temporalis origin and insertion

O: temporal fossa and fascia

I: coronoid process, anterior edge of ramus of the mandible

digastric origin and insertion

O: mastoid process (deep to sternocleidomastoid and splenius capitis)

I: inferior border of the mandible

suprahyoids origin and insertion

geniohyoid and mylohyoid- O: underside of mandible

stylohyoid- styloid process

I: hyoid bone

occipitofrontalis origin and insertion

O: galea aponeurotica

frontalis- I: skin superior to eyebrows

occipitalis- I: superior nuchal line of the occiput

lateral pterygoid origin and insertion

superior head- O: infratemporal surface and and crest of greater wing of sphenoid bone

inferior head- O: lateral surface of lateral pterygoid plate of sphenoid bone

I: articular disc and capsule of temporomandibular joint, neck of mandible

medial pterygoid origin and insertion

O: medial surface of lateral pterygoid plate of sphenoid bone, tuberosity of maxilla

I: medial surface of ramus of the mandible

sternocleidomastoid action

unilaterally- laterally flex the head and neck to the same side, rotate the head and neck to the opposite side

bilaterally- flex the neck, assist to elevate the rib cage during inhalation

anterior scalene action

unilaterally- with the ribs fixed, laterally flex the head and neck to the same side, rotate the head and neck to the opposite side

bilaterally- elevate the ribs during inhalation, flex the head and neck

middle scalene action

unilaterally- with the ribs fixed, laterally flex the head and neck to the same side, rotate the head and neck to the opposite side

bilaterally- elevate the ribs during inhalation

posterior scalene action

unilaterally- with the ribs fixed, laterally flex the head and neck to the same side, rotate the head and neck to the opposite side

bilaterally- elevate the ribs during inhalation

masseter action

-elevate the mandible (temporomandibular joint)

-may assist to protract the mandible (TM joint)

temporalis action

-elevate the mandible (TM joint)

-retract the mandible

digastric action

-with the hyoid bone fixed, depress the mandible (TM joint)

-with the mandible fixed, elevate the hyoid bone

-retract the mandible

suprahyoids action

-elevate hyoid and tongue

-depress mandible (TM joint)

occipitofrontalis action

frontalis- raise the eyebrows and wrinkle the forehead

occipitalis- anchor and retract the galea posteriorly

lateral pterygoid action

unilaterally- laterally deviate the mandible to the opposite side

bilaterally- protract the mandible

medial pterygoid action

unilaterally- laterally deviate the mandible to the opposite side

bilaterally- elevate the mandible, protract the mandible

sternocleidomastoid nerve innervation

-spinal accessory n. (XI)

-C2, C3

anterior scalene nerve innervation

C(3), C4-C8

middle scalene nerve innervation

C(3), C4-C8

posterior scalene nerve innervation

C(3), C4-C8

masseter nerve innervation

trigeminal n. (V)

*mandibular division

temporalis nerve innervation

trigeminal n. (V)

*mandibular division

digastric nerve innervation

anterior belly- trigeminal n. (V) (mandibular division)

posterior belly- facial n. (VII)

suprahyoids nerve innervation

geniohyoid- C1-C2

mylohyoid- trigeminal n. (V)

stylohyoid- facial n. (VII)

occipitofrontalis nerve innervation

facial n. (VII)

lateral pterygoid nerve innervation

trigeminal n. (V)

medial pterygoid nerve innervation

trigeminal n. (V)