PCBI101: MUSCULAR QUIZ

• MUSCLE TONE


  The constant tension produced by the body's muscles for a long period
• ISOMETRIC


  A type of muscle contraction where there is no movement, but increased tension in the muscles
• ELASTICITY


  The ability of muscle tissue to return to its original length after contraction or extension
• PERIMYSIUM


  The connective tissue enveloping bundles of muscle fibers
• RESTING MEMBRANE POTENTIAL


  The charge difference across the membrane of an unstimulated cell membrane
• TETANUS


  A condition where the muscles remain contracted without relaxing
• ACETYLCHOLINE


  The neurotransmitter produced and released by the motor neuron upon the arrival of the nerve impulse
• ATP


  The form of energy that muscles and all cells of the body use
• HYPOTONIA


  Also known as floppy baby syndrome, a condition of low muscle tone
• THRESHOLD


  The weakest stimulus needed to produce a response
• Acetylcholine attaches to receptors on the sarcolemma to allow sodium ions to enter the muscle
• During a muscle contraction, the H zone and I band shorten but the A band stays the same
• Rigor mortis is a condition when a person dies and no ATP is available to release cross-bridges
• Synapse is where nerve cell and muscle fiber meet
• In repolarization the Na+ is lower in the cell making it negatively charged which is a resting membrane potential
• Sliding filament mechanism is the process used by muscles to contract
• Skeletal muscles must be stimulated by a nerve to contract
• Diffusion of Na+ in the cell generates action potential
• The part of the sarcomere with only actin filaments is called the I band
• When action potentials cease the muscle stops contracting
• Walking is an example of isometric contraction
• Fibers do not contract partially, they either do or don't
• Ca2+ causes synaptic vesicles to release acetylcholine into the synaptic cleft
• Ca2+ binding to tropomyosin causes troponin to move exposing attachment sites for myosin
• Striations of skeletal and cardiac muscle are due to sarcomeres (actin and myosin)
• Cerebral palsy is a group of disorders that affect movement and muscle tone or posture
• The following are typical symptoms of Prader-Willi syndrome: an excessive appetite and overeating, floppiness caused by weak muscles (hypotonia), and learning difficulties
• People with myotonic dystrophy often have prolonged muscle contractions and are not able to relax certain muscles after use
• Rigidity is the type of stiffness related to uncontrolled reflexes
• Becker Muscular Dystrophy begins between ages 2 and 3