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48 Cards in this Set
- Front
- Back
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what is the name of the plasma membrane of a muscle fiber?
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sarcolemma
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What is a isometric contraction?
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a contraction in which the tension within the muscle changes, but the length of the muscle does not.
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What would attempting to pick up an object too heavy result in?
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It results in ISOmetric contraction.
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What is myosin?
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a protein within thick filaments that contain cross-bridges.
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What ion is necessary for cross-bridging?
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Calcium ions are nesscessary for what?
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What are endomysium?
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individual muscle fibers
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What are skeletal muscles innervated by?
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somatic motor neurons
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What connective tissue sheath envelopes bundles of muscle fascicles?
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epimysium
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What are the major functions of muscles?
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movement, protection, heat production, and posture
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What is the plasma membrane of a muscle fiber?
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sarcolemma
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In the structure called the triad, the T-tubule is positioned where?
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between the sarcoplasmic reticulum.
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What is the function of the T-tubule?
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to allow for electrical signals to move deeper into the cell.
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The neurotransmitters secreted at the motor end plate of the skeletal muscle are called?
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acetylcholine
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What is acetylcholine?
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neurotransmitters secreted at the motor end plate of skeletal muscle
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A motor unit is most correctly described as a?
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muscle fiber and a motor neuron.
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What is the sarcoplasmic reticulum
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an elaborate network of membranes in skeletal muscle cells that store calcium.
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During muscle contraction, myosin cross bridges attach to what?
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actin filaments.
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What is a state of sustained muscle contraction called?
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muscle tone
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What do somatic motor neurons innvervate?
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skeletal muscle
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What is the most distinguishing characteristic of muscle tissue?
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the ability to transform chemical energy
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What is the major function of the sarcoplasmic reticulum?
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to regulate intracellular calcium concentration
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What is calmodulin?
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the site of Calcium regulation in smooth muscle cells
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What is treppe?
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the warm-up period required by athletes in order to bring their muscles to peak performance.
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What are white fibers?
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fast fibers.
are also also known as what? |
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A lack of ATP, High levels of lactic acid, high levels of metabolic waste products, all may lead to what?
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muscle fatigue.
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What are the proteins associated with thin myofilaments?
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Troponin, tropomyosin, actin.
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The treppe effect is also termed as?
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the staircase phenomenon
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What is hypertrophy?
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an increase in muscle size without an increase in the number of cells
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What are the functional characteristics of skeletal muscles?
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contractibility, extensibility, excitability
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What do skeletal muscles look like?
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they are long, cylindrical, and have many nuclei
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In skeletal muscle, where do Calcium muscles bind to?
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they bind to the TROPONIN molecule.
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3 Characteristics of thin filaments are:
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1.) composed of actin proteins
2.)contain regulatory proteins 3.)it is a helical structure that looks like a double strand of pearls. |
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What is troponin. Name 2 characteristics.
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Troponin is a protein found on the actin filament.
It is calcium dependent, and if calcium binds to it, it will then expose the actin filament binding site. |
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What is influx?
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the flow of sodium ions into the cell.
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What is the synaptic cleft?
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the space that separates the axonal ending and the muscle fiber.
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What is excitability?
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the ability of a muscle to receive and respond to a stimulus.
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What happens in excitation-contraction coupling? 4
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the actin potential travels along the muscle cell wall, calcium ions are released from the sarcoplasmic reticulum, calcium binds to troponin, and myosin heads bind to actin active sites.
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What is tetanus:
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the sustained state of muscle contraction
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What is needed in order for the myosin head to bind to the actin active site?
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calcium first binds to troponin
tropomyosin blocking actin needs to be removed, ATP is required. |
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Give an example of typical skeletal muscle contraction.
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moving your feet and walking.
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What is absolute refractory period?
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the period where a muscle will not contract irrespective of the rate or strength of the stimulus.
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What is isometric contraction:
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change in the muscle tension without a change in muscle length.
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What system does Duchenne Dystrophy attack?
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the muscular system
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What is contractibility?
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the ability of the muscle cell to shrink (contract) forcibly when adequately stimulated.
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At -90 mV, the concentration of sodium is:
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high in the extracellular
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Three characteristics of Thick filaments:
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1.composed of myosin protein.
2. has a rod like tail and 2 globular heads. 3.)the myosin head is the binding site for ATP |
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What does lack of ATP result in?
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it results in locking of actin filaments to the myosin head, and this results when cells undergo respiration in the absence of Oxygen.
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The resting membrane for a muscle cell is -90 mV with a threshold value of -60 mV. What would opening the K+ voltage gates result in?
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Hyperpolarization.
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