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31 Cards in this Set
- Front
- Back
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Three Types of Muscle Tissue
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1) skeletal muscle
2) cardiac muscle 3) smooth muscle |
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Muscle Contraction has four possible functions:
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1) body movement
2) stabilization of body position 3) movement of substances through the body 4) generating heat to maintain body temperature |
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What kind of muscle tissue is skeletal muscle tissue?
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voluntary muscle tissue (it can be consciously controlled)
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Tendon
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connects muscle to bone
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Ligament
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connects bone to bone
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Agonist
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the muscle responsible for the movement (contracts)
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Antagonist
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the muscle that stretches when the agonist contracts
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Synergistic Muscles
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assist the agonist by stabilizing the origin bone or by positioning the insertion bone during the movement
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T or F: contraction of skeletal muscle may squeeze blood and lymph vessels aiding circulation
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True
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Shivering
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controlled by the hypothalamus upon stimulation by receptors in the skin and spinal cord, is the rapid contraction of skeletal muscle to warm the body
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How does a muscle use leverage?
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It applies a force to a bone at its insertion point and rotates the bone in some fashion about the joint.
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Sarcomere
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The smallest functional unit of skeletal muscle. It is composed of many strands of 2 protein filaments (thick and thin) laid side by side to form a cylindrical segment.
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Sarcoplasmic Reticulum
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Each myofibril (sarcomeres are positioned end to end to form a myofibril) is surrounded by this. The lumen is is filled with Ca+ ions.
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Skeletal muscle is ____nucleate
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multi
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Sarcolemma
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A modified membrane called the sarcolemma wraps several myofibrils together to form a muscle cell or muscle fiber.
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Thick Filament
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made of the protein myosin, several long myosin molecules wrap around each other to form one thick filament
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Thin Filament
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composed mainly of a polymer of the globular protein actin (attached to the actin are the proteins troponin and tropomyosin)
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T or F: The H zone and the I band get smaller, while the A band does not change size
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True
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Neuromuscular Synapse
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A neuron attaches to a muscle cell forming a neuromuscular synapse. The action potential of the neuron releases acetylcholine into the synaptic cleft.
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T-Tubules
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The action potential moves deep into the muscle cell via these small tunnels in the membrane. They allow for a uniform contraction of the muscle by allowing the action potential to spread through the muscle cell more rapidly.
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Motor Unit
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The neuron and the muscle fibers that it innervates (independent of each other)
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What does the force of a contracting muscle depend upon?
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The number and size of the active motor units, and the frequency of the action potentials in each neuron of the motor unit.
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T or F: Fingers have larger motor units than back muscles
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False
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Myoglobin
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Stores oxygen inside muscle cells. Can only store one molecule of oxygen.
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T or F: Muscle cells always can divide.
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False. They are so specialized that they have lost the ability for mitosis.
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Striated
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Both cardiac and skeletal muscle are striated (composed of sarcomeres)
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How many nuclei does one cardiac muscle cell contain?
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ONE
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Intercalated Disc
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Separates one muscle cell from another. They contain gap junctions which allow an action potential to spread from one cardiac cell to the next (via electrical synapses)
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The action potential of cardiac muscle
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exhibits a plateau after depolarization, which is created by slow-voltage-gated calcium channels which allow calcium to enter and hold the inside of the membrane at a positive potential difference (plateau lengthens time of contraction)
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Smooth muscle is innervated by:
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autonomic nervous system
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Read Page 164-182 [LAST THING]
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Biology, lectures 8 and 9
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