~ 60% of skeletal muscles are axial muscles: muscles of head and neck, muscles of vertebral column, muscles of abdomen, muscles of pelvic floor. Muscles of facial expression: don"t need to know origins/insertion. Occipitofrontalis: muscles on front and back of skull that can pull skin on top of head back and forth, raise/lower eyebrows. Platysma: muscle that flares out, attaches to skin, flares out in neck. A: bilaterally flexes vertebral column in neck region, extends head, elevates sternum on forced inspiration. Unilaterally laterally flexes & rotation of head towards side opposite contracting muscles. Anterior (c3-c6) to first rib, middle(c2-c7) to first rib, posterior (c4-c6) to 2nd rib. Space between muscles is where brachial plexus comes out. If muscles are stretched they can damage brachial plexus. The intrinsic muscles of the back form 3 distinct layers: superficial: move the neck, intermediate: extend the vertebral column, deep: interconnect vertebrae. Take off latissimus dorsi, trapezius, etc, then you have these muscles.