click below
click below
Normal Size Small Size show me how
A&P1-5 Muscular Sys
Ch 5: Muscular System
Term | Definition |
---|---|
Acetylcholine (ACh) | Neurotransmitter released to stimulate a contraction of skeletal muscle tissue. (must meet threshold amount for muscles to react; adding more ACh to the threshold will not give bigger response) |
Aerobic respiration | Type of cellular respiration requiring oxygen that results in enough energy to generate 36 ATP molecules from each glucose molecule & produces carbon dioxide & water. (for endurance; converts pyruvic acid to carbon dioxide & water) See slow-twitch fibers. |
Anaerobic respiration | Type of cellular respiration in the absence of O2 resulting in enough energy to generate 2 ATP molecules from each glucose molecule & produce lactic acid (bursts of energy; converts pyruvic acid to lactic acid as a waste product.) See fast-twitch fibers |
Antagonist | A muscle that has an opposite action (ex: raise hand from waist to mouth-biceps brachii contract (shorten) & triceps brachii relax (lengthen) |
Extension | The ability to be stretched (action that bends a part of the body posteriorly, such as straightening the arm at the elbow.) |
Fascicle | Group of muscle fibers surrounded by perimysium |
Fatigue | The inability of a muscle to fully respond to a nerve impulse. |
Flexion | Action that bends a part of the body anteriorly, such as flexing the elbow |
Insertion | The attachment of a muscle to a bone or structure that does move when the muscle contracts. |
Isometric | A type of contraction in which the length of the muscle remains constant while the tension in the muscle increases. (muscles stays the same) |
Isotonic | A type of contraction in which the tension in the muscle remains constant and motion is the result. (muscle shortens & lengthens. Ex: boxer moving his arm during the punch, the tension in his muscles remained constant and motion was the result.) |
Lever | A rigid object that can be used to lift something. Bones act as levers in lever systems that muscles use to move the body. |
Motor unit | A single nerve cell and all the muscle cells it stimulates |
Muscle twitch | The contraction of one muscle cell due to one nerve impulse |
Origin | The attachment of a muscle to a bone or structure that does not move when the muscle contracts |
Recruitment | The process of getting more and more motor units involved in a contraction to create a larger motion. (ex: there is rapid recruitment in a boxer’s punch) |
Sarcomere | A section of a myofibril extending from one Z line to the next |
Sliding filament theory | An explanation of muscle contraction that involves thick myofilaments grabbing thin myofilaments and pulling them toward the center of the sarcomere |
Synergists | Muscles that have the same action (ex: raise hand from waist to mouth-biceps brachii contract (shorten) & triceps brachii relax (lengthen) |
Tetany | A sustained contraction brought about by a high frequency of nerve impulses. (ex: like holding a pencil, muscles can’t enter relaxation phase or you’ll drop the pencil. (a sustained contraction brought about by a high frequency of nerve impulses.) |