| A | B |
|---|
| myosin | main protein found in thick filaments of muscle |
| actin | main protein found in thin filaments of muscle |
| myoglobin | stores oxygen for use during cellular respiration in muscles |
| H zone | region within muscle fiber containing only thick filament |
| A band | region of muscle fiber that extends the full length of the thick filament |
| I band | region of muscle fiber containing only thin filament |
| mitochondria | cellular structure that provides ATP during muscle contractions |
| cellular respiration | process that occurs in the mitochondria |
| isotonic contraction | type of contraction that produces movement |
| isometric contraction | type of contraction that produces no movement |
| muscle hypertrophy | an increase in muscle size |
| muscle atrophy | a wasting away of muscle |
| origin | point of muscle attachment on the bone that remains stationary |
| insertion | point of attachment to the bone that moves |
| agonist | muscle that creates the desired movement |
| antagonist | muscle that extends while an agonist is contracting |
| skeletal muscle | category of muscle that is under voluntary control |
| cardiac muscle | category of muscle that has no regenerative ability |
| smooth muscle | category of muscle found in walls of tubular structures |
