Muscle Physiology

2. Functional unit of a skeletal muscle fiber defined as the region from one Z-line to the next Z-line
5. This connects the muscle to the bones
6. A connective tissue outside the epimysium that surrounds and separates the muscles
10. Theory explaining how muscles contract, wherein actin filaments slide over myosin filaments resulting in a shortening of the length of the sarcomeres, and hence, a shortening of the muscle fibers
11. Connective tissue that encases muscle fiber groups
12. Cytoplasm of a muscle cell
14. Type of contraction wherein the muscle does not shorten and does not require the sliding of myofibrils
17. cells
19. A regulatory protein that allows myosin heads to bind to actin (initiating muscle contraction) when (certain ions bind) bound with calcium ions

1. Tissue found only in the heart
2. Plasma membrane of the muscle cell
3. Type of isotonic contraction wherein muscle fibers lengthen during contraction
4. Layer that separates the muscle from surrounding environment
7. Covers active actin filament sites to prevent binding with myosin and initiating contraction
8. Are long ribbon-like fibers of a muscle cell composed of threadlike proteins
9. Ion responsible for exposing the active site on actin when it binds to troponin
13. This causes the contractions of skeletal muscles
15. The increase in the volume of an organ or tissue due to the enlargement of its
16. One of the 2 filaments forming the contractile part of the muscle that appears thin and light and is more abundant
18. A vertical line located in the middle of the H zone at which accessory proteins hold together thick filaments