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56 Cards in this Set
- Front
- Back
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This system is responsible for moving the body
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Muscular system
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These are the organs of the muscular system
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Individual muscles
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Largest muscle in human body
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gluteus maximas
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3 Functions of muscular system
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1. Movement of body or its parts
2. Heat production 3. Posture |
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Skeletal muscles are composed of:
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nervous tissue
vascular tissue connective tissue skeletal tissue |
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Type of connective tissue over skeletal muscles
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Fascia tissue
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Bundle of muscle fibers is called
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Fassicles
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Individual muscle fiber has numerous:
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duclei
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The sarcoplasm (aka muscle's cytoplasm) contains:
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mitochondria
sarcoplasmic reticulum myofibrils |
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Myofibrils are composed of thousands of smaller fibers called:
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Microfilaments
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Skeletal muscle is often referred to as
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Striated muscle
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One of the patterns of on the myofibril is called
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Z Line
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Area between two Z lines is called
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Sarcomere
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The Sarcomere is the _____ unit.
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Contractile
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This is the name for a nerve cell attached to muscle fibers
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Motor neuron
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The motor unit contains
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The motor neuron
Cell fibers |
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Point where motor neuron attaches to a muscle fiber is called
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neuromuscular junction
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What generates a muscle impulse
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When the motor unit receives a stimulus and acetylocholine is released which allows impulse to travel across synapse
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Muscle fiber contractions results from a
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sliding movement of the think and thick filaments.
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Thick filaments consist of a protein called:
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myosin
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Head of a myosin molecule is called
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cross-bridge
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cross bridge has a __________ like action
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Hinge
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When energized, the myosin cross-bridge has a strong attraction for
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binding sites on the thin filaments
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Thin filaments consist of globular molecules of
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actin twisted into a helix.
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Actin molecules have a binding site for
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myosin cross-bridges
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Cross-bridges cannot bind to the actin when
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the binding sites are covered by troponin (protein)
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A muscle fiber is usually stimulated by
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acetylcholine
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Acetylcholine causes _____ to the motor end plate.
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depolarization
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Muscle impulse reaches the deep parts of the fiber by means of the ___
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Tranverse tubules
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Muscle impulse signals the sarcoplasmic reticulum to release _____
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calcium ions
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Calcium ions bind to the troponin which causes___
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the tropomysin to move exposing the actin cross-bridge binding sites.
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Actual movement is caused by
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reaction between actin and myosin filaments
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ATP does what to the cross-bridges
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Breaks the link
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ATP is chemically converted into ADP and phosphate. This releases
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Heat
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how long can rigor mortis last in humans?
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Up to 72 hours
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Muscle fibers relax when
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calcium ions are transported back into sarcoplasmic reticulum
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Entire muscle movement is referred to as
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Sliding filament model
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Fingers have the _____ number of muscle fibers per motor unit.
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fewest
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Larger muscles have ____ number of muscle fibers
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largest
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Muscles are ______ to respond in the legs than in the mars
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slower
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Threshold Stimulus
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minimum amount of stimulation needed to cause muscle fiber to contract.
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None or all principle
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Muscles either contract with force or not at all. No middle ground or half contraction.
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Recruitment of motor units
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as intensity is needed, additional motor units are used in system to add force or tension.
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movement produced by a muscle is called
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its action
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Insertion
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moveable end of a skeletal muscle
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Origin
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immovable end of a skeletal muscle
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prime mover
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agonist is muscle responsible for most of movement
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Synergists
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muscles that work or assist the prime mover
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Antagonist
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muscles that oppose the movement of the prime mover
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Why do muscle fibers have more mitochondria than found in other cells?
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Mitochondria provide energy a cell needs to function. Muscle cells require more energy to move, thus more mitochondria.
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Why is the gleutus maximus so large in humans?
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Bipedalism
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What structure is the contractile unit of a myofibril?
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Sarcomeres
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What is a motor unit?
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Motor Neuron
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What is a neuromuscular junction?
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Where motor neuron attaches to muscle fiber.
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What role do motor neurons play in the functioning of muscle tissue?
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It releases acetylcholine which generates muscle impulse.
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What is function of transverse tubules?
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Transmit signal into cell interior
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