Term | Definition |
Abduct | to move away from the midline of the body |
Actin | a contractile protein of muscle |
Action Potential | the change in electrical potential of a muscle fiber when stimulated |
Adduct | to move towards the midline |
Aerobic | oxygen requiring |
Aerobic Endurance | the length of time a muscle can continue to contract using aerobic pathways |
Aerobic Exercise | exercise such as biking, swimming, jogging, that causes more efficient muscle and general body metabolism |
Anaerobic | not requiring oxygen |
Anaerobic Threshold | The point at which muscle metabolism converts to anaerobic glycolosis |
Antagonist | muscle that reverses or opposes the action of another muscle |
Aponeurosis | fibrous or membranous sheet connecting a muscle and the part it moves |
Arrector Pili | tiny, smooth muscle attached to hair follicles |
Ataxia | Disruption if muscle coordination resulting in inaccurate movements |
Atrophy | reduction in size or wasting away of an organ or cell resulting from disease or lack of use |
Biceps | two-headed, especially applied to certain muscles |
Calcaneal tendon | tendon that attaches the calf muscles to the heel bone; Achilles tendon |
Calcium channel blockers | drugs that interfere with the movement of calcium across the plasma membrane, thus inhibiting muscle contractions |
Contraction | to shorten or develop tension, an ability highly developed in muscle cells |
Contracture | fibrosis of connective tissue in skin, fascia, muscles, or joint capsules that prevents normal mobility of the related tissue or joint |
Convulsion | a rapid series of involuntary muscular contractions and relaxations, especially of the skeletal muscles |
Cramp | sustained spasm, or titanic contraction of an entire muscle, which lasts for just a few seconds or several hours, causing the muscle to become taut or powerful |
Effector | muscle capable of being activated by nerve endings |
Electromyography | the recording, study preparation, and interpretation of graphic record of the contractions of muscles as a result of electrical stimulation |
Endomysium | thin connective tissue surrounding each muscle cell |
Epimysium | sheath of fibrous connective tissue surrounding a muscle |
Fascia | layers of fibrous tissue covering and separating muscles |
Fascicle | bundle of muscle fibers bound together by connective tissue |
Fibromyositis | a group of conditions involving inflammation of a muscle, its connective tissue coverings and tendons, and capsules of nearby joints |
Fibrosis | the abnormal formation of, or degeneration into, fibrous tissue; may occur around the membranes of the lungs as a result off an inflammation or pneumonia; may also occur in and around the arteries |
Fibrositis | an inflammation and hyperplasia of white fibrous tissue, especially that which forms muscle sheaths and fascia layers |
Fixator | muscle that immobilizes one or more bones, allowing other muscles to act from a stable base |
Flaccid | a condition in which the muscles are uncommonly weak, flabby, or soft; may be indicative of a defect in muscular tone |
Fulcrum | the fixed point on which a lever moves when force is applied |
Hernia | protrusion of an organ through its body cavity wall |
Hypertrophy | increase in size of a tissue or organ independent of the body's general growth |
Insertion | movable attachment of a muscle |
Irritability | ability to respond to a stimulus |
Isometric contraction | contraction in which the muscle tension remains constant and the muscle shortens |
Isotonic contraction | contraction in which the muscle tension remains constant and the muscle shortens |
Kymograph | a recording instrument used in muscle physiology experiments |
Lever system | consists of a lever (bone), effort (muscle action), resistance (weight of object to be moved), and fulcrum (joint) |
Mechanical advantage | condition that occurs when the load is close to the fulcrum and the effort is applied far from the fulcrum |
Mechanical disadvantage | condition that occurs when the load is far from the fulcrum and the effort is applied near the fulcrum |
Muscle fatigue | state of physiological inability to contract; results from relative deficit of ATP, ionic imbalances |
Muscle spindle | encapsulated receptor found in skeletal muscle that is sensitive to stretch |
Muscle tone | sustained partial contraction of a muscle in response to stretch receptor inputs; keeps muscle healthy and ready to act |
Myalgia | Muscle pain |
Myectomy | surgical removal of a portion of a mucle |
Myoclonus | the spastic, shock-like contractions of a part of a muscle or the entire muscle, usually a symptom of a convulsive disorder |
Myofibril | rod-like bundle of contractile filaments found in muscle cells |
Myofilament | actin and myosin bands within sarcomeres |
Myoglobin | red pigment that stores oxygen within muscle cells |
Myokymia | an involuntary twitching or quivering of a muscle |
Myoma | a tumor characterized by containing muscle tissue |
Myomalacia | the abnormal softening of muscle tissue |
Myopathy | disease of muscles |
Myosclerosis | the abnormal softening of muscle tissue |
Myosin | one of the principal contractile proteins found in muscle |
Myositis | inflammation of a muscle or muscles |
Myotonia | a condition involving irregular tonic spasms of a muscle or the temporary rigidity of a muscle after normal contraction |
Origin | attachment of a muscle that remains relatively fixed during muscular contractions |
Paralysis | a temporary or permanent loss of functional motion or sensation of a muscle or muscles due to an impairment of the neural or muscular mechanism |
Perimysium | the sheath of connective tissue surrounding a bunch of muscle fibers |
Peristalsis | progressive, wavelike contractions that move foodstuffs through the alimentary canal or other hollow organs |
Pronation | inward rotation of the forearm causing the radius to cross diagonally over the ulna |
Resistance exercise | high intensity exercise in which the muscles are pitted against high resistance or immovable forces, and, as a result, muscle cells increase in size |
RICE | rest, ice, compression, and elevation; standard treatment for a pulled muscle or excessively stretched tendon or ligaments |
Sarcolemma | plasma membrane of muscle cell |
Sarcomere | the smallest contractile unit of muscle |
Sarcoplasm | cytoplasm of muscle cell but it contains unusually large amounts of stored glycogen and myoglobin |
Spasm | a sudden involuntary muscle twitch ranging in severity from merely irritating to very painful |
Sphincter | a circular muscle surrounding an opening; acts as a valve |
Strain | excessive stretching and possible tearing of a muscle due to muscle overuse or abuse |
Supination | the outward rotation of the palms causing palms to face anteriorly |
Synergist | muscle that aids the action of a prime mover by effecting the same movement or by stabilizing joints across which the prime mover acts to prevent undesirable movements |
Tendonitis | an inflammation of a tendon and the tendon-muscular attachment |
Tetanus | a state of sustained contraction of a muscle that is a normal aspect of skeletal muscle functioning |
Twitch | a single, rapid contraction of muscle in response to a stimulus |