Muscular

• Acetylcholine


  Chemical messenger released from the end of a motor neuron
• Actin


  Protein of which the thin myofilaments are composed
• Aerobic respiration


  Process that breaks down fatty acids for energy when oxygen is present
• Anaerobic respiration


  Process that breaks down glucose for energy when oxygen is not plentiful
• Antagonist


  Muscles that oppose the action of a prime mover
• Aponeurosis


  Flat, broad tendon that attaches a muscle to another muscle or to bone
• ATP

  Adenosine triphosphate; used for energy in cells to perform various functions, including muscle contraction
• Atrophy


  Decrease in the size of a muscle
• Belly


  The thick midsection of the muscle
• Complete tetanus


  Condition in which impulses arrive so fast the muscle cannot relax between stimuli and twitches merge into one prolonged contraction
• Creatine phosphate


  Compound stored in muscle that is used for short bursts of high-energy activity
• Endomysium


  Delicate connective tissue covering each muscle fiber
• Epimysium


  Connective tissue covering that surrounds muscles as a whole and binds all muscle fibers together
• Fascia


  Connective tissue surrounding the muscle
• Fascicles


  Bundles of muscle fibers
• Hypertrophy


  Enlargement of a muscle
• Incomplete tetanus


  Condition of rapid muscle contraction with only partial relaxation
• Insertion


  The end of a muscle that attaches to the more mobile bone
• Isometric contraction


  Contraction in which the tension within a muscle increases while its length remains the same
• Isotonic contraction


  Contraction in which the muscle changes length to move a load
• Motor unit


  A neuron and all the muscle fibers it stimulates
• Muscle fiber


  A skeletal muscle cell
• Muscle tone


  Continuous state of partial muscle contraction that allows for the maintenance of posture
• Myofibrils


  Long protein bundles that fill the sarcoplasm of a muscle fiber
• Myofilaments


  Fine protein fibers that make up a myofibril
• Myosin


  Protein of which the thick myofilaments are composed
• Neuromuscular junction


  Connection between a motor neuron and a muscle fiber
• Origin


  The end of a muscle that attaches to the more stationary bone
• Perimysium


  Sheath of connective tissue encasing fascicles
• Prime mover


  The main muscle triggering a movement
• Sarcomere


  The unit of contraction of the myofibrils of a muscle
• Sarcoplasm


  The cytoplasm of a muscle fiber
• Synaptic cleft


  Narrow space between the end of a motor nerve and the muscle fiber
• Synergists


  Muscles that assist in the movement of a bone
• Tendon


  Strong, fibrous cord through which a muscle attaches to a bone
• Transverse (T) tubules


  Tubules that extend across the sarcoplasm and allow electrical impulses to travel deep into the cell
• Treppe


  Phenomenon in which each successive twitch contracts more forcefully than the previous one
• Twitch


  Single, brief contraction
• According to VanPutte, Regan, & Russo (2016), muscle tissues are unique enough to be modified by the ones who owns it. One can change its size and type of muscle fibers thereby enabling enhancement of strength and endurance like what we've been observing to athletes.
• Moreover, muscle cells are elongated thus the term muscle fiber for every muscle cell.