Exam 2 Actions, Insertions, Innervations, Origins

sternocleidomastoid origin

manubrium and medial 1/3 of clavicle

sternocleidomastoid insertion

mastoid process

sternocleidomastoid actions

flexes the neck draws head to shoulder

turns face to opposite side

accessory muscle of respiration

sternocleidomastoid innervation

spinal accessory nerve

Omohyoid inferior belly origin

superior border of scapula

Omohyoid inferior belly insertion

intermediate tendon

Omohyoid inferior belly action

depresses hyoid

Omohyoid inferior belly innervation

ansa

anterior scalene origin

transverse processes of C3 to C6

anterior scalene insertion

1st rib

anterior scalene action

bilaterally — flexes the neck

singly — flexes neck laterally

elevates 1st rib during forced inspiration

anterior scalene innervation

ventral rami of cervical nerves

middle scalene origin

transverse processes of C2-C7

middle scalene insertion

1st rib

middle scalene actions

bilaterally — flexes the neck

singly — flexes neck laterally

elevates 1st rib during forced inspiration

middle scalene innervation

ventral rami of cervical nerves

posterior scalene origin

transverse processes of C5 and C6

posterior scalene insertion

2nd rib

posterior scalene actions

bilaterally — flexes the neck

singly — flexes neck laterally

elevates 1st rib during forced inspiration

posterior scalene innervation

ventral rami of cervical nerves

infrahyoid (strap) muscles function

pull down on the hyoid (lowers pharynx/larynx)

stabilizes hyoid

infrahyoid (strap) muscles innervation (except thyrohyoid)

ansa cervicalis

thyrohyoid innervation

nerve to the thyrohyoid (C1)

thyrohyoid action

depresses hyoid bone

anterior digastric origin

intermediate tendon

anterior digastric insertion

mandible

anterior digastric action

depresses mandible; raises and steadies hyoid bone during swallowing and speaking

anterior digastric innervation

nerve to mylohyoid

mylohyoid origin

mylohyoid line of mandible

mylohyoid insertion

hyoid bone

mylohyoid action

elevates hyoid bone

mylohyoid innervation

nerve to mylohyoid

geniohyoid origin

inferior genial tubercles

geniohyoid insertion

hyoid bone

geniohyoid action

elevates hyoid bone

geniohyoid innervation

nerve to geniohyoid (C1)

posterior digastric origin

digastric notch

posterior digastric insertion

intermediate tendon

posterior digastric action

depresses mandible; raises and steadies hyoid bone during swallowing and speaking

posterior digastric innervation

facial nerve

stylohyoid origin

styloid process

stylohyoid insertion

greater horn of hyoid

stylohyoid innervation

facial nerve

stylohyoid action

elevates hyoid bone

omohyoid superior belly innervation

ansa

omohyoid superior belly action

depresses hyoid

sternothyroid innervation

ansa

sternothyroid action

depresses larynx

sternohyoid innvervation

ansa

sternohyoid action

depresses hyoid bone