1. Muscles
Head, Neck and Torso

2. Over 600 Muscles

3. Muscles
2 separate groups: for every bone, there’s a muscle on the back of the bone and a muscle on the front
Frontal muscles: in general function is to flex, flexor muscles
Back: in general  exstensors (of arm or leg)
Flex: joint angle decreasing
Extend: straightening

4. Muscles are Named By: # of origins: Action Direction of muscle fibers:
Rectus - straight
Transverse – horizontal
Oblique – diagonally
Location:
Pectoralis – chest
Frontalis – over the frontal bone
Shape:
Serratus – saw toothed
Deltoid – triangular
Origin and insertion
Sternocleidomastoid
# of origins:
Biceps
Triceps
Action
Adductor
Flexor – extensor
Supinator – pronator

5. Muscles of Facial Expressions* * * * * * * * * *

6. Muscles that Move the Head
Sternocleidomastoid
Depresses(flexes neck), rotates head
Scalenes
Anterior, middle and posterior
Help turn head side to side
Lifts the first 2 ribs to assist inspiration

7. Anterior Abdominal Rectus Abdominis External Oblique Internal Oblique
“six pack”
Flexes spine/torso
Stabilizes body
External Oblique
Rotation of torso
Stabilize
Internal Oblique
Same as above

9. Anterior Abdominal Diaphragm Main muscle in inspiration
Separates abdomen from thorax

10. Intercostal Muscles Internal Intercostals External Intercostals
Forced Expiration
External Intercostals
Aid in inspiration

11. Muscles that Move the Shoulder Girdle (anterior)
Pectoralis major
Prime mover in shoulder flexion, flexes, adducts arm medially
Pectoralis minor
Pulls scapula forward (anteriorly) and downward
Serratus Anterior
Rotates scapula upward & laterally

12. Muscles that Move the Shoulder Girlde (posterior)
Trapezius:
Extends head, shrugs shoulder
Adducts scapulae
Levator Scapulae
Elevates scapula
Rhomboid major and minor
Pulls scapula inward

13. Muscles that Move the Humerus
Latissimus dorsi
Arm extension and adduction
Pulls arm posteriorly
Teres Major and Teres Minor
Work synergistically with above (adduction)
Deltoid
Shoulder abduction