1. Mader Chapter 7 1-5 on page 133

2. 1. Skeletal – voluntary (attached to skeleton) 2. Cardiac – involuntary (heart) 3. Smooth – involuntary (walls of hollow internal organs)

3. 1. Produce movement – picking up an object 2. Resist movement – posture, blood pressure (Newton’s 3 rd Law: muscles generate a force (static tension) that exactly opposes and equal but opposite force being applied to a body part 3. Generate heat – contraction of our muscles accounts for > 75% of all heat generated by the body – shivering thermogenesis 4. Stabilizing joints – stabilize & strengthen

4.  A group of many individual cells, all w/same origin and insertion and all with the same function (p. 115)  Arranged in bundles called fascicles  Each bundle is enclosed in a sheath of fibrous connective tissue called fascia  Each fascicle contains 12 to 1000s of individual muscle cells – called muscle fibers  The outer surface of the whole muscle is covered with several more layers of fascia – at the ends all come together forming tendons

5.  Tube shaped 3 cm – 30 cm (thigh)  Can contain more than one nucleus just under the cell membrane (skeletal)  Nearly entire cell is packed with long cylindrical structures in parallel called myofibrils  Myofibrils are packed with contractile proteins called actin and myosin  When myofibrils contract the muscle cell also contracts

6.  Each skeletal muscle fiber is a long, cylindrical cell w/multiple oval nuclei just beneath the sarcolemma (plasma membrane) surface  Fibers are large, 10 to 100  m in diameter, and up to hundreds of centimeters long  Sarcoplasm, similar to cytoplasm of other cells, but has numerous glycosomes (=organelle full of glycogen) and a unique oxygen-binding protein called myoglobin, similar to hemoglobin

9.  A single myofibril within one muscle cell (in your biceps) can contain > 100,000 sarcomeres arranged end to end.  100,000 sarcomeres all shortening at once produces a muscle contraction  Understanding muscle shortening is simply understanding how a single sarcomere works

10. From Z to shining Z

11.  2 kinds of proteins 1) Myosin – thick filaments interspersed @ regular intervals with a different protein 2) Actin – thin filaments that are structurally linked to the Z-line  Myosin filaments are completely contained within the sarcomere  Muscle contractions depend on the interaction of these 2 filaments

15. 1. Nerves activate skeletal muscles 2. Activation releases calcium 3. Calcium starts the sliding filament mechanism 4. Contraction ends when nerve activation ends  Sliding filament model of contraction

17.  http://video.google.com/videosearch?ndsp=1 8&um=1&hl=en&q=sliding%20filament%20of %20contraction&ie=UTF-8&sa=N&tab=iv# http://video.google.com/videosearch?ndsp=1 8&um=1&hl=en&q=sliding%20filament%20of %20contraction&ie=UTF-8&sa=N&tab=iv#  grants.hhp.coe.uh.edu/clayne/6397/Unit3.ht m grants.hhp.coe.uh.edu/clayne/6397/Unit3.ht m

18. 1. Lots of mitochondria form ATP by aerobic cellular respiration 2. Muscles contain creatine phosphate (high E storage supply) used to regenerate ATP indirectly 3. ATP produced anaerobically when oxygen supply is limited

19.  Continued intake of oxygen (panting) to complete the metabolism of lactic acid (built up anaerobically)  Lactic acid is transported to the liver and broken down into carbon dioxide and water