1. The Muscular System

2. Important Terms for Muscle Movement Origin point of attachment to the more stationary bone Insertion point of attachment to the more movable bone Nerve innervation what nerve “ talks ” to the muscles to cause contraction or relaxation Action coordinated response of a group of muscles to bring body into movement TREND: When a muscle contracts, it shortens. This shortening causes the muscle ’ s insertion to move toward the origin … movement

3. Muscles for Practice Biceps brachii Origin Insertion Nerve Innervation Action Use 3 references to complete the chart: Wingerd pgs. 213, 223 BRB pg. 366 Musculoskeletal Anatomy pgs. 5, 7, 25, 75

4. Production of Movement OriginInnervation Insertion Action Prime mover (agonist) muscle that causes a desired action Antagonist muscle that relaxes & yields to the prime mover Synergist muscle that works with prime mover … steadying the movement by stabilizing the joint & moving bones Fixator muscle that stabilizes the bone & joint at the muscle ’ s origin

5. Types of Muscle Contraction Isotonic contraction –Produces movement as the muscle pulls on the bone –Consistent load through a range of motion –2 types Concentric (+) –Muscle shortens & pulls on bone to produce movement –Decreases joint angle Eccentric (-) –Muscle length increases during contraction to produce movement Isometric contraction –Produces muscle tension but muscle does not shorten –Same length