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Muscle Contraction
Glossary - Muscle Contraction
Term | Definition |
---|---|
Acetylcholine | a chemical released from certain nerve endings, especially those innervating skeletal muscles |
Action Potential | a rapid change in electrical activity across a nerve or muscle membrane, usually due to a rapid flow of sodium ions across the membrane into the cell |
Adenosine Di phosphate (ADP) | one of the chemical products of the break down of Adenosine Triphosphate (ATP) for energy during muscle contraction |
Adenosine Triphosphate (ATP) | a chemical that serves as the immediate source of chemical energy for most of the energy consuming reactions of the body, especially for muscle contraction. ATP is split into ADP and phosphate to form energy. |
Alpha Motor Neurons | nerves that cause skeletal muscle fibers (extrafusal fibers) to contract |
Cross Bridges | the linkages between thick and thin filaments during muscle contraction |
Depolarization | reduction in the electrical charge across the resting cell membrane |
Motor Neuron | a nerve cell that conducts an impulse from the central nervous system to muscles or glands |
Motor Unit | a motor neuron and all the muscle fibers which it innervates |
Neuromuscular Junction (motor endplate) | the junction between motor nerve ending and sarcolemma membrane of a muscle fiber |
Sarcolemma | the muscle fiber membrane |
Sarcoplasm | the cytoplasm of muscle fibers |
Sarcoplasmic Reticulum | a network of channels extending throughout muscle fibers; regulates the availability of calcium to the troponin molecules of the thin filaments |
Transverse Tubules (T-Tubules) | channels that conduct action potentials from the surface of a muscle fiber to the interior of the fiber |
Tropomyosin | a protein in the thin filaments of skeletal muscle; blocks attachment sites on actin |
Troponin | a protein in the thin filaments of skeletal muscle; inhibits myosin ATPase activity until troponin is inactivated by calcium ions released from the sarcoplasmic reticulum |
Muscle Properties | force that causes joints to move; irritability, contractibility, distensibility, elasticity, and reparability |
Muscle Functions | pulley/lever system, stores creatine phosphate for quick energy, protects glands and organs. gives definition to body, maintains body temperature, and helps pump the blood in veins back to the heart |
Individual muscle fibers......(finish sentence) | always contract in a straight line |
What are the two categories of contraction planes? | Fusiform & Pennate (3 types of pennate-fan shaped muscles |
What are the 3 types of pennate-fan shaped muscles? | Unipennate, Bipennate, Multipennate |
Fusiform | straight muscle fibers; these fibers run longitudinal and parallel with the muscle's long axis |
Pennate Muscles | fan shaped muscles and they have tendons that run parallel with the muscle's longitudinal axis with the muscle fibers running obli |
Name 6 Types of Muscles | Triangular, Bicipital, Multipennate, Bipennate, Unipennate, Fusiform |
Name the Planes of Motion | Median line defines the center of the right and left sides. Front plane = anterior. Back plane = posterior. Outer side = lateral. *if exercise is out of alignment , planes of motion are less efficient. |
Leverage: The longer the lever,..... | the more muscle strength it takes to lift the same amount of weight. (takes more strength with a longer forearm) |