A. Read pg. 182… B. Origin and Insertion 1. Where do muscles attach? a. “one end attaches to an immovable part and one end attaches to a moveable part” 2. Origin – the immovable end of the muscle 3. Insertion – the moveable end of the muslce *When a muscle contracts, its insertion is pulled toward its origin. 4. Can have more than one origin or insertion.

a. Ex: Biceps Brachii 5. Flexion vs. Extension decreasing joint angle increasing joint angle

C. Interaction of Skeletal Muscles 1. Agonists vs. Synergists a. Agonists – prime mover muscle b. Synergists – other muscles that aid in movement or stability. c. Ex: lifting your arm up…  deltoid = agonist  trapezius, levator scapulae… = synergist d. Antagonist – act as a prime mover against a muscle.  What would the antagonist be of the triceps brachii? Biceps brachii

A. Superficial Muscles – name may indicate size, shape, location, action, number, or direction of fibers. 1. Ex: pg. 184 (bolded) -pectoralis major… -deltoid… -extensor digitorum… -biceps brachii… -sternocleidomastoid… -external oblique… large triangle function Two heads or origins Attachment sites Location and muscle fiber direction

B. Facial Expression Muscles MuscleOriginInsertionAction Epicranius (frontalis- occipitalis) Orbicularis Oculi Orbicularis Oris Buccinator Zygomaticus Platysma

C. Mastication Muscles MuscleOriginInsertionAction Masseter Temporalis

D. Muscles that Move the Head MuscleOriginInsertionAction Sternocleidomastoid Splenius Capitus Semispinalis Capitus

E. Muscles that move the Pectoral Girdle MuscleOriginInsertionAction Trapezius Rhomboideus major Levator scapulae Serratus anterior Pectoralis minor

F. Muscles that move the Arm MuscleOriginInsertionAction Coracobrachialis Pectoralis major Teres major Latissimus dorsi Supraspinatus Deltoid Subscapularis Infraspinatus Teres minor

G. Muscles that move the forearm MuscleOriginInsertionAction Biceps Brachii Coracoid Process Radial Tuberosity Flexes Forearm BrachialisHumerusRadiusFlexes Forearm Triceps Brachii Tubercle below glenoid cavity Olecranon Process Extends Elbow

H. Muscles that move the thigh MuscleOriginInsertionAction Gluteus Maximus SacrumPosterior femurExtends thigh Gluteus MediusIlium Greater Trochanter of femur Abducts thigh Gracilis Pubic Symphysis TibiaAdducts Thigh

I. Muscles that move the leg MuscleOriginInsertionAction SartoriusIliac SpineTibiaFlexes leg Biceps FemorisXXFlexes leg SemitendinosusXXFlexes leg SemimembranosusXXFlexes leg Rectus FemorisXXExtends knee Vastus lateralisXXExtends knee Vastus MedialisXXExtends knee Vastus Intermedius XXExtends knee

J. Muscles that move the foot MuscleOriginInsertionAction Tibialis anteriorTibia1 st metatarsalDorsiflexion Gastrocnemius Condyles of femur CalcaneusPlantar flexion Soleus Head of fibula and tibia CalcaneusPlantar flexion