axial muscles

obicularis oculi

closes eye, aids flow in tears (muscle of facial expression)

obicularis oris

purse lips (muscle of facial expression)

zygomaticus major

elevate mouth, lateral pull on the mouth (muscle of facial expression)

zygomaticus minor

elevate mouth (muscle of facial expression)

buccinator

pull mouth laterally but press down against cheek (think of sucking) (muscle of facial expression)

superior oblique

gaze down and laterally CN4

superior rectus

gaze up CN3

lateral rectus

gaze laterally CN6

medial rectus

down gaze into nose CN3

inferior oblique

gaze upward and laterally CN3

inferior rectus

gaze down CN3

masseter

elevate mandible

temporalis

elevate mandible

pterygoids

elevate mandible

laterally move mandible

muscles of the tongue

palatoglossus

styloglossus

genioglossus

hyoglossus

sternocleidomastoid and function

sternum to mastoid process

CN11

same side lateral flexion of the neck

opposite side rotation

internal intercostals

pull upper rib down

depress rib

forced exhalation

external intercostals

pull up on inferior rib

inhalation

external oblique general action

compress abdomen

depress ribs

same side unilateral flexion

opposite side rotation

internal oblique

compress abdomen

depress ribs

lateral flexion of torso

same side rotation

rectus abdominis

depress ribs

flexion of vertebral column

compress abdomen

general function of the three layers of the intrinsic back muscles

• Superficial: posture & big movements

• Intermediate: stabilization & fine control

• Deep: segmental stability & proprioception