BIOLOGY 235 MIDTERM 2 REVIEW CHAPTER 11: THE MUSCULAR SYSTEM

BIOLOGY 235 MIDTERM 2 REVIEW CHAPTER 11: THE MUSCULAR SYSTEM origin - stationary bone, usually proximal Insertion - attachment of muscle's other tendon to movable bone, usually distal belly (body) - fleshy portion of muscle between their tendons (origin and insertion) Actions - main movements that occur when the muscle contracts reverse muscle action (RMA) - during specific movements the actions are reversed; • bones act as levers, and joints function as the fulcrums of these levers • lever: rigid structure that can move around a fixed point called a fulcrum • effort: causes movement force exerted by muscular contraction • load or resistance: opposes movement. • the load is typically the weight of the body part that is moved or some resistance that the moving body part is trying to overcome - motions occur when effort applied at insertion exceeds the load mechanical advantage - only needs small amount of force to move load over small distance mechanical disadvantage - larger amount of force to overcome load