1. Muscle Tissue 2 Muscle Contrations

2. The Sliding Filament Theory The thin filaments (actin) slide over the thick causing the sarcomere to shorten. This process requires ATP

4. Mechanism of Filament Sliding Animation http://www.blackwellpublishing.com/ma tthews/myosin.html

5. Neuromuscular Junction Where a muscle is innervated -OR- Place where a nerve meets a muscle

6. Neuron Nerve Cell

7. Motor Neuron The nerve that stimulates a muscle to contract

8. Motor End Plate Axon of a motor neuron that attaches to the sarcolemma of the muscle fiber Muscle   Neuron  Motor End Plate

9. Motor Unit The combination of the motor neuron and the muscle it innervates

11. Physiology of Contraction An action potential causes the release of Ca+2 ions stimulating the myosin to move the actin filament http://www.brookscole.com/chemistry_d/templates/student_resources/shared_resources/an imations/muscles/muscles.html (labeling picture)

12. Muscle Contraction Summary http://bcs.whfreeman.com/thelifewire/c ontent/chp47/4702001.html Narrated Summary with tabs

13. Energy for Contraction The body uses ATP for energy This ATP can be produced by the body in 3 ways

14. Phosphagen System ADP + P + Energy  ATP Fast Not a lot of energy

15. Anaerobic System 1C 6 H 12 O 6  2C 3 H 6 O 3 + ATP Glucose is broken down into Pyruvic Acid Needs no oxygen Not a lot of ATP

16. Aerobic System 1C 3 H 6 O 3 + O 2  CO 2 + H 2 O + ATP Starts with Pyruvic Acid from Anaerobic Needs Oxygen to take place Makes a lot of energy Many Steps - longest

17. What Happens When You Exercise The muscle cells burn off the ATP they have floating around in about 3 seconds. The phosphagen system kicks in and supplies energy for 8 to 10 seconds. This would be the major energy system used by the muscles of a 100-meter sprinter or weight lifter, where rapid acceleration, short-duration exercise occurs. If exercise continues longer, then the glycogen-lactic acid system kicks in. This would be true for short-distance exercises such as a 200- or 400-meter dash or 100-meter swim. Finally, if exercise continues, then aerobic respiration takes over. This would occur in endurance events such as an 800- meter dash, marathon run, rowing, cross-country skiing and distance skating.

19. All or None Principle When a muscle fiber is stimulates it either completely contracts or does not contract at all

20. Threshold Stimulus – the weakest stimulus that can cause a muscle to contract Sub-Threshold Stimulus – a stimulus that is too weak to cause a contraction

22. Myogram A record of the electrical activity of a muscle to determine the type of contraction

23. Twitch A rapid, jerky response to a single stimulus

24. Latent Period – time between the application of the stimulus and the muscle contraction Contraction Period – time when filament are sliding over each other, causing a contraction Relaxation Period – Time during which filaments are sliding back into place Refractory Period – Time following a contraction during which a muscle is unable to respond to a stimulus

25. Latent Period Contraction Period Relaxation Period Refractory Period

26. Tetanus A sustained contration

27. Treppe A muscle contracts more forcefullu after contracting several times

28. Isotonic Tension remains constant but the muscle shortens Lifting

29. Isometric Tension increases but muscle does not shorten

30. Muscle Tension The force of a muscle contraction

31. Muscle Tone State of partial contraction – muscle is tight but not causing movement

32. Muscular Atrophy Wasting away of muscle

33. Muscular Hypertrophy Increase in the size of muscle fibers