1. Nerve MUSCLE PHYSIOLOGY

2. Dystrophin-Glycoprotein Complex
Merosin

3. Dystrophin-Glycoprotein Complex
Large Protein=
Forms a rod which connects the actin filament to the transmembrane protein Beta-Dystroglycan in the sarcolemma.
Function
Add strength to the muscle by providing a scaffolding for the fibrils and connecting them to the Extra cellular matrix

5. ACTIN FILAMENTS Composed of three Protein components:
1. F-Actin strands formed by G-Actin Globular Proteins. MW = 42,000
2. Tropomyosin. - M W =70,000
3. Troponin ,comprised of 3 subunits
a. Troponin-T
b. Troponin-I
c. Troponin-C
G-Actin
F-Actin

6. Components of Actin FilamentsG- F-

7. ACTIN FILAMENTS
RELAXED
EXCITED

8. Myosin filaments Comprised of multiple Myosin Molecules M W = 480,000
Each Myosin Molecule is formed by:
Heavy Chains - MW 200,000 (Two)
Light Chains – MW 20,000 (Four)

9. MYOSIN FILAMENTS
Heavy Chain

10. CROSS SECTION OF SARCOMERE

11. Muscle Contraction (Active sites Exposed)
Relaxed
Contracted

12. Interaction B/W Actin & Myosin

13. Walk Along Theory

14. Walk Along (Ratchet) Theory

15. Relaxed & Contracted