1. Muscle Anatomy and Physiology The Review!

2. Skeletal Muscle Functions Locomotion Movement Maintaining Posture Generating Heat!

3. Characteristics Excitability: Membrane potentials, action potentials, Na+ and K+ Contractility: Sarcomeres, Sliding Filament Theory, Ca++ and ATP Extensibility Elasticity

4. Anatomy: Max Min Muscle, fascicle, fiber, fibrils containing sarcomeres, filaments – actin and myosin Fascia / epimysium, perimysium, endomysium “Bundles within bundles”

5. Contractile units: SARCOMERES Thin: actin, troponin, tropomysim Thick: myosin Sarcomere Regions: Z- lines, A-band, I-band, H- Zone

6. Sliding Filament Theory of Contraction All-or-None Sarcomere units shorten by thin and thick filaments “sliding” past each other Requires Ca++ Requires ATP

7. Excitability! The stimulus to contract Resting Membrane Potential: Membranes separate charges: polarized with positive Na+ outside Depolarization: Charge reversal across membrane

8. Depolarization reaches Threshold voltage and All-or-None Depolarization travels along membrane Action Potential AP travels along sarcolemma T- tubules sarcoplasmic reticulum Terminal Cisternae Calcium released Troponin-Calcium move Tropomysin exposing myosin binding sites Why all the Excitement?

10. Remember the Simulation? Motor Nerve – Muscle Fiber Pre-Synaptic Terminal: Acetylcholine released Post-Synaptic Terminal: Ach binds to Ach receptors =>Muscle fiber depolarization Contraction!

11. The Neuromuscular Junction An Interesting Place to Chemically Manipulate Neuro- Muscular Function…Causing Paralysis or Worse…

12. Motor Units = Motor Control Motor Neuron + Muscle fiber(s): fine vs. strong Twitch: Single contraction & relaxation Recruitment: Smooth moves Tetanus: Sustained contraction

13. Energetics of Contraction ATP-PC: fast, limited Anaerobic Glycolysis: cytosolic breakdown of Glucose without O2 Aerobic Oxidation: slow, but plentiful supply of ATP

14. Final Exam: 20 Multiple Choice 2 Matching: Bundles of bundles, and movement terms 5 Short Answers: ATP systems Roll of Calcium in Contraction Sarcomere: Anatomy and Function Poisons/Drugs affecting NMJ – Neurotransmitters Your Burning Question/Answer