1. Muscle Function and Anatomy

2. Function of Muscle Motion of joints Movement of body fluids - pump blood, peristalsis Regulation of body fluids - bladder Body stability Heat production - 85%

3. Muscle Architecture

4. How Are Muscles Built? In circular sections Deepest section contains two proteins Myosin Actin Myosin is surrounded by actin

5. Myofibrils Bundles of actin and myosin

7. Muscle Fiber Among others things, a muscle fiber contains many groups of myofibrils

10. Fascicle A group of muscle fibers bundled together.

11. The Whole Muscle

13. Muscle Membranes

14. Tendons All 3 membranes converge to form a tendon which connects the muscle to the bone

15. Muscle Fiber Arrangement p. 25 Pennate muscles Greater cross sectional area – greater force (strength) production Parallel muscles Longer muscles – greater range of motion

16. Parallel muscles 1.Flat (rectus abdominus) 2.Fusiform (biceps) 3.Strap (sartorius) 4.Radiate (trapezius) 5.Spincter Pennate 1.Unipennate (biceps femoris) 2.Bipennate (rectus femoris) 3.Multipennate (deltoid) Muscle Fiber Arrangement Strap

17. Types of Muscle Contraction p. 28 Isometric (Static) Isotonic (Dynamic) Concentric Eccentric

18. Types of Muscle Contraction Concentric contraction - If muscle force is greater than the resistance Static or Isometric contraction - If muscle force is equal to the resistance Eccentric contraction - If muscle force is less than the resistance

19. Lengthens

20. Eccentric Contraction Used to control agonist and prevent over lengthening of the antagonist. Example: triceps lowers dumbbell while biceps ’controls’ the triceps activity (action). Causes more damage than other types Greater repair required… …producing a stronger muscle Also, results in more muscle soreness.

21. TABLE 2.1Type of Contraction Isometric Isotonic ConcentricEccentric Agonist muscleNo changeShorteningLengthening AntagonistNo changeLengtheningShortening Joint angleNo changeIn direction of forceIn direction of external resistance Direction of body partAgainst immovable object Against gravity or external force Consistent with gravity or external force MotionPressure but no motionCauses motion DescriptionStaticDynamic shorteningDynamic lengthening Muscle force v. Resistance F = RF > RF < R SpeedEqual to resistanceFaster than the inertia of the resistance Slower than the speed of gravity or applied inertial forces Acceleration or Deceleration ZeroAD Symbol=+-

22. ROLE OF MUSCLES Agonist – prime mover Antagonist – have an action opposite to the agonist Stabilizers – fixate or stabilize the joint Synergists – assist or guiding Neutralizers – counteract or neutralize movements

23. Agonist and Antagonist

24. Types of Muscle Fibers Fast twitch Slow twitch

25. Questions?