1. Physiology of the Musculoskeletal System Chapters 7 & 8

2. 1. Neuromuscular Anatomy Pages 121-122, 126-129, 131, & 136

3. Nervous System Central Nervous System Peripheral Nervous System 3 CentralNervousSystemPeripheralNervousSystem

4. Afferent & Efferent Afferent Efferent Central Nervous System

5. Neuron

6. Synapse

7. Neuromuscular Junction

9. Action Potential Electrical impluse Neurons and muscle fibers Two phases Depolarization Sodium (Na) Potassium (K) Repolarization Sodium (Na) Potassium (K) Electrical impluse Neurons and muscle fibers Two phases Depolarization Sodium (Na) Potassium (K) Repolarization Sodium (Na) Potassium (K)

10. Action Potential

11. Depolarization Repolarization

12. Motor Unit Note: This motor unit has a 3:1 ratio Actual motor units range from 20:1 to 2,000:1

13. Motor Neurons Thick myelin sheath; fast action potential Thin myelin sheath; slow action potential

14. Motor Units 100-1000 per muscle Fast and Slow All-or-None Principle 100-1000 per muscle Fast and Slow All-or-None Principle

15. 2. Muscle Anatomy Overview Pages 141-152

16. Muscle Fiber Anatomy Note: muscle fiber = muscle cell

17. Muscle Fiber Anatomy

18. Sarcomere

19. Myofibrils/Filaments - actin - myosin

20. Actin & Myosin 3 2 1 1. Troponin 2. Tropomyosin 3. Actin

21. Actin & Myosin Actin Myosin

22. 3. The Sliding Filament Theory Excitation-Contraction Coupling

23. Sliding filament theory Step-by-Step Summary of Excitation-Contraction Coupling p. 145 http://www.blackwellpublishing.com/matthews/myosin.html http://www.mhhe.com/biosci/esp/2002_general/Esp/folder_structure/su/m4/s11/sum4 s11_9.htm

24. Neural Stimulation

25. Action Potentials & Acetylcholine

26. Calcium

28. Cross-Bridges & Power Strokes

29. Sliding

30. Sliding Relaxed Partial Maximal

31. ATP ( ✧ ) 1. 2.

33. Quick Time Movie This Quick Time Movie of the contraction process can be downloaded at the class web page.

34. Muscle Force Force = The capacity to do work or cause physical change When in the sliding filament theory is muscle force actually produced? Force = The capacity to do work or cause physical change When in the sliding filament theory is muscle force actually produced?

35. 4. Types of Muscle Contraction Static contraction Isometric Dynamic contraction Concentric Eccentric Static contraction Isometric Dynamic contraction Concentric Eccentric Pages 158-159

36. Isometric

37. Isometric or Static Contraction

38. Concentric

39. Concentric Contraction

40. Eccentric

41. Eccentric Contraction

43. Lengthens Eccentric Contraction

44. 5. Muscle Fiber Types Most Common: Slow twitch/Type I Fast twitch A/Type IIa Fast twitch B/Type IIb Type IIx Pages 153-154

45. Fiber Type Characteristics Fast FibersSlow fibers CharacteristicType IIType I Resistance to fatigueLowHigh Predominant energy system AnaerobicAerobic Speed of shorteningFastSlow Force productionHigh Moderate Fiber DiameterLargeSmall Others

46. Fiber Typing FYI

47. The things I’ll do for extra credit! FYI

48. Fiber Typing Type IIa Type IIb Type I Fig 8.12 Type I Type II FYI

49. Fiber Types and Individual Differences What are the percentages of fiber types in the average person? 107.5 kg (237 lbs) at clean & jerk in 1997. Bodyweight was 53.1 kg (117 lbs). Western States 100 two weeks later won Badwater Ultramarathon

50. Fiber Type Distribution SportType IType II Distance Runner 70-8020-30 Track Sprinter25-3070-75 Non-athlete47-53 Table 8.2

51. Fiber Type Distribution Average person; equal mix No sex difference No age difference Average person; equal mix No sex difference No age difference

52. Fiber Type Distribution

53. Alterations in Fiber Types Shift “skeletal muscle is highly plastic” Complete change Fast twitch to Slow twitch rigorous and regular exercise Shift “skeletal muscle is highly plastic” Complete change Fast twitch to Slow twitch rigorous and regular exercise 16 weeks of endurance training 6% increase in Type I 1% decrease in Type IIa 5% decrease in Type IIb

54. 6.Muscle Receptors Pages 163-165

55. Stretch Reflex stretch or increase length of the muscle......muscle contraction stretch or increase length of the muscle......muscle contraction

56. Muscle Spindle

58. Golgi Tendon Organ

59. 4. Inhibition 1. Contraction 2. 3.