Unit3 Lab9 AXIAL

orbicularis oris

action: closes the lips

orbicularis oculi

action: closes the eyes

buccinator

action: compresses cheeks

platysma

action: tenses skin of neck, pulls lower lip back and down

temporalis

insertion: coronoid process of mandible

action: elevates and retracts mandible

masseter

action: elevates the mandible

sternocleidomastoid

origin: manubrium, sternal end of clavicle

insertion: mastoid process

action: unilateral- laterally flexes head to same side and rotates head to opposite side, bilateral- flexes head

splenius capitis

action: unilateral- laterally flexes and rotates head to same side, bilateral- extends head

semispinalis capitis

action: unilateral- rotates vertebral column and head to opposite side, bilateral- extends vertebral column and head

spinalis group

action: extends vertebral column

longissimus group

action: unilateral- laterally flexes vertebral column to same side and rotates head to same side, bilateral- extends vertebral column and head

iliocostalis group

action: unilateral- laterally flexes vertebral column to same side, bilateral- extends vertebral column

diaphragm

action: prime mover of inspiration

external intercostals

action: pulls ribs towards one another to elevate rib cage; aids in inspiration

internal intercostals

action: draws ribs together to depress rib cage; aids in forced expiration

rectus abdominis

origin: pubic crest and symphysis

insertion: xiphoid process; costal cartilage of ribs 5-7

actions: flexes and rotates vertebral column; compresses abdominal wall

external/internal oblique

action: unilateral- rotates and laterally flexes vertebral column to same side, bilateral- flexes vertebral column and compresses abdominal wall

transversus abdominis

action: compresses abdominal wall