1. Unit 11: Human Health and Physiology Lesson 11.2 Muscles and Movement Text Correlation: 11.3/11.4/11.5

2. Roles of nerves, muscles, ligaments, tendons and bones in producing movement Nerves- provide impulse that makes muscles contract Tendons- connect muscle to bone Ligaments- connect bone to bone Bone- provide structure Muscles- attach 2 bones Muscle Contraction 1) A nerve impulse reaches muscle. 2) The impulse triggers muscle contraction. 3) Muscles are attached to bone by tendon. 4) Bone moves.

3. Draw a diagram of the human elbow joint Identify: cartilage, synovial fluid, joint capsule, named bones, bicep, and tricep

4. Functions: Synovial fluid- provides food, oxygen, and lubrication to cartilage Cartilage- cushion against friction. Tendons- connect bone to muscle (attach bicep to scapula) Ligaments- connect bone to bone and keep them in correct place. Humerus- connected to bicep and tricep muscle. Radius/Ulna- help rotate forearm. Bicep- bend the arm Tricep- straighten arm

5. Hip and Knee Joints: Similarities: –Both are synovial joints –Both involved with movement of the leg –Both are required for walking Differences: –Ball vs hinge joints –Multiaxial vs single axis movement –Flex and extend plus rotation and abduction and adduction (move sideways) vs flex and extend only

6. Striated Muscle Fibers Muscle cells contain many nuclei because lots of cells fused together The sarcolemma is the membrane surrounding the muscle cell. Sarcoplasma the cytoplasm of a muscle cell Saroplasmic reticulum is the internal membrane that stores and releases calcium ions (Ca 2+ ) TONS of mitochondria found in the sarcolemma Myofibrils thin fibers found inside a muscle cell –These fibers are light and dark and are what cause the striated (striped) look of a skeletal muscles

7. Sarcomere Z-lines, actin, myosin (w/heads), light and dark bands I-Band: actin filaments attached to the Z-line (light section) A-Band: Myosin filaments (dark section) Sarcoplasmic reticulm: found across the fibers and regulates calcium ions

8. Muscle Contraction: Sliding Filament Theory Overview: Actin and Myosin filaments slide over each other to make the muscle shorter (contract). Myosin heads act as hooks and pull actin closer. 1) Calcum ions flood sarcoplasmic reticulum due to a nerve impulse. Calcium ions attach to troponin ( 1 st protein associated with actin) which is attached to tropomyosin (2 nd protein associated with actin) This uncovers the binding sites on actin for myosin 2) Myosin binds to ATP  ADP +P  Myosin in high energy configuration (SET). 3) Actin/myosin cross-bridge forms. 4) Myosin releases ADP + P  relaxes to low energy state, cross bridge moves actin filament. 5) Myosin binds to new ATP  releases cross-bridge. 6) ATP  ADP + P  Myosin back in high energy configuration.

9. Sliding Filament Theory: Animation 2 Animation 1

10. Electron Micrograph Z-Line I-Band (actin) A Band (myosin & Actin