1. Portion of action potential when inside of plasma membrane is returning to resting membrane potential, becoming more negative 6. Acetylcholine binds to -gated ion channels 7. Ability of muscle to recoil to original resting length after stretched 9. Mature cartilage cell 11. Smooth muscle is controlled by this branch of the peripheral nervous system 13. Basic functional unit of muscle contraction; From Z disk to Z disk 14. Type of muscle fatigue resulting from emotional state of an individual 17. Inflammation of fibrous connective tissue following prolonged skeletal muscle tension 19. Protein covering active sites on actin during state of muscle relaxation 21. Decrease in muscle size over time 22. Type of bone formation resulting from calcification of cartilaginous tissue 23. Muscle fiber type that responds rapidly to nervous stimulation; rapid breakdown of ATP; few mitochondria 24. A state of muscle contraction when the tension of muscle fibers change while maintaining consistent length