Muscle Anatomy and Physiology Overview

1. Epimysium: The outer membrane of a muscle formed from connective tissue.

2. Endomysium: The membrane around an individual muscle fiber.

3. Perimysium: The membrane surrounding a group of muscle fibers.

4. Fascicle: A group of muscle fibers.

5. Myofibril: Long fibers inside a muscle cell that help it contract.

6. Sarcomere: The basic unit of muscle contraction.

7. Actin: The thin filament in muscle fibers that helps with contraction.

8. Myosin: The thick filament in muscle fibers that helps with contraction.

9. Cardiac Muscle: Muscle tissue found in the heart.

10. Action Potential: The chemical/electric signal that triggers muscle contraction.

11. Cross-Bridge: The part of muscle fibers that connects actin and myosin during contraction.

12. Anaerobic: The energy process in muscle fibers that doesn't require oxygen.

13. Aerobic: The energy process in muscle fibers that requires oxygen.

14. Glycolysis: The process where glucose is quickly turned into energy (ATP) in a cell.

15. Lactic Acid: A substance that builds up in muscles during intense exercise and causes fatigue.

16. Electrons: Tiny particles that help transfer energy inside cells.

17. Motor Units: A motor neuron and the muscle fibers it controls, working together for movement.

18. Slow Twitch Fibers: Muscle fibers that use oxygen for energy and are good for long, steady activities.

19. Concentric Contraction: When a muscle shortens while contracting (like lifting a weight).

20. Eccentric Contraction: When a muscle lengthens while contracting (like lowering a weight).

21. Isometric Contraction: When a muscle contracts but doesn't change length (like holding a plank).

22. Flexion: Bending a joint (like bending your elbow).

23. Extension: Straightening a joint (like straightening your elbow).

24. Abduction: Moving a body part away from the center of the body (like lifting your arm to the side).

25. Adduction: Moving a body part toward the center of the body (like lowering your arm back to your side).

26. Neuro-Muscular Junction: The point where a nerve and muscle meet to allow movement.

27. Motor Neuron: A nerve cell that sends signals to muscles to make them move.

28. Creatine Phosphate: A molecule that helps muscles quickly produce energy during short, intense activity.

29. Krebs Cycle: A process in cells that helps produce energy from food molecules.

30. Electron Transport Chain: A series of reactions that make most of the energy (ATP) in cells.

31. Mitochondria: The part of a cell that produces energy (ATP).

32. Fusiform Muscle: A muscle with a spindle shape, wider in the middle and narrower at the ends (like the biceps).

33. Pennate Muscle: A muscle with angled fibers, making it good at generating force (like the quadriceps).

34. Circular Muscle: A muscle that forms a ring around an opening (like the muscles around your eyes).

35. Smooth Muscle: Involuntary muscle found in organs, like the stomach or intestines.

36. Skeletal Muscle: Voluntary muscle attached to bones, responsible for movement.