Muscles

Front 1

Buccinator

Back 1

Origin: maxilla and mandible Insertion: orbicularis oris Action: Draws corner of mouth laterally; compreses check; holds food between teeth during chewing

Front 2

Masseter

Back 2

Origin: zygomatic arch and maxilla
Insertion :angle and ramus of mandible
Action: close jaw and elevate mandible

Front 3

Sternocleidomastoid

Back 3

Origin: Manubrium of sternum and medial portion of clavicle
Insertion: mastoid process of temporal bone and superior nuchal line of occiptial bone
Action: flex/rotate head

Front 4

Scalenes anterior, middle, and posterior

Back 4

Origin: Transverse processes of cervical vertebrae
Insertion: anterolaterally on ribs
Action: Flex and slightly rotate neck; elevate ribs 1-2 (aid in inspiration)

Front 5

Pectoralis major

Back 5

Origin: clavicle, sternum, cartilage of ribs 1-6 and aponeurosis of external oblique muscle
Action: prime mover of arm flexon: adducts, medially rotates. Pulls chest upward.

Front 6

serratus anterior

Back 6

origin: lateral aspect of ribs 1-8(or9)
Insertion: vertebral boarder of anterior surface of scapula
Action Moves scapula forward toward chest. rotates scapula. abduction and raising of arm

Front 7

Deltoid

Back 7

Origin: Lateral 1/3 of clavicle; acrmoion, and spine of scapula
Insertion; deltoid tuberosity of humerus
Action: Acting as a whole, prime mover of arm abduction. Can aid in flexion, extension and rotation of humerus.

Front 8

Diaphragm

Back 8

Origin:Inferior boarder of rib and sternum, costal cartillages of last six ribs and lumbar vertebrae
Insertion: centeral tendon
Action: prime mover of inspiration flattens on contraction, increasing vertical dimensions of thorax; increases intra abdominal pressure

Front 9

Rectis abdominis

Back 9

origin- pubis insertion- sternum, costal cartilage, and some ribs Action- flexes vert. column, supports and compresses abdominal viscera.

Front 10

trapezius

Back 10

Origin: Occipital bone: ligamentum nuchae; spines of c7 and all thoracic vertebrae
Insertion: acromion and spinous process of scapula
Action: stabilizes, raises, retracts and rotates the scapula. the superior fibers elevate, the middle fibers retract, and the inferior fibers depress the scapula. together the upper and lower fibers rotate the arm.