The Muscular System

1. The Muscular System Part II Skeletal Muscle Contraction

2. Introduction • Muscles receive… • Actin and myosin… • Sarcomeres… • Muscle fibers… • Pulls on…

3. Fig. 9.8

4. Neuromuscular Junction • Each skeletal muscle fiber ___________ connected to a neuron • Neurons (Motor Neurons) 1. 2. 3. • Neurotransmitters 1. 2. 3. 4.

5. Neuromuscular Junction • Synapse 1. 2. • Ach receptors 1. 2.

6. Fig. 9.8

7. Fig. 9.9

8. Fig. 9.8

9. Stimulus for Contraction • Muscle impulse 1. 2.

10. Excitation Contraction Coupling • Muscle impulse causes … • Ca2+ binds to … • Binding sites … • Actin can…

11. Fig. 9.10

12. The Sliding Filament Theory • Sarcomeres… • Thin and thick filaments … • Slide past one another 1. 2. 3.

13. Fig. 9.11

14. Fig. 9.11

15. Cross-Bridge Cycling • Sarcomere shortening 1. 2. 3. • ATP is required 1. 2. • Cross- bridge binding repeats 1. 2.

16. Fig. 9.10

17. Relaxation • Nerve impulse… • Acetylcholinesterase 1. 2. • Calcium … • Myosin… • Tropomyosin … *ATP … • Rigor mortis

18. Fig. 9.10

20. Diseases of the Muscular System • Polio 1. 2. • Botulism 1. 2.

21. Clin. App. 9.1: Myasthenia Gravis 1. 2. 3. Symptoms a. b. 4. Treatment a. b. c. d.