CHAPTER 9

·      LO 9.1.1 Compare and contrast the three basic types of muscle tissue.

o   What are the three types of muscle?

o   Where is each type of muscle located?

o   Is each muscle type striated? Is it branched? Is it voluntary? Can it contract without stimulation from the nervous system?

·      LO 9.1.2 List four important functions of muscle tissue.

o   What are four important characteristics of muscle tissues?

o   What are four important functions of muscle tissues?

·      LO 9.2.1 Describe the gross structure of a skeletal muscle.

o   What is the relationship between muscles, muscle fascicles, and muscle fibers?

o   Which connective tissue sheath surrounds _________

§  each muscle fiber?

§  each muscle fascicle?

§  each muscle?

·      LO 9.3.1 Describe the microscopic structure and functional roles of the myofibrils, sarcoplasmic reticulum, and T tubules of skeletal muscle fibers.

o   What is the special name given to the plasma membrane of a muscle fiber?

o   What is the name given to bundles of myofilaments found inside muscle fibers?

o   What is a sarcomere and which two myofilaments overlap to create a sarcomere?

o   In which segment of a sarcomere do we find only thick filaments? Only thin filaments (in a relaxed muscle)? Both thick and thin filaments?

o   What protein makes up thick filaments? Thin filaments?

o   Which structure of a thick filament is able to bind to the actin of a thin filament?

o   What is the sarcoplasmic reticulum, and what is its function?

o   What are T tubules, and what are their function?

·      LO 9.3.2 Describe the sliding filament model of muscle contraction.

o   What is the function of sarcomeres and of myofilaments in the sliding filament model of contraction?

o   What happens to the distance between the sarcomere’s Z-discs and M-line during muscle contraction?

·      LO 9.4.1 Explain how muscle fibers are stimulated to contract by describing events that occur at the neuromuscular junction.

o   What are the four stages of skeletal muscle contraction? Which two cells are required for skeletal muscle contraction?

o   What are six steps that happen at the neuromuscular junction that lead to excitation of the skeletal muscle fiber? It can be useful to draw a picture of each event as you describe it in your own words.

o   What is an action potential? Do neurons experience them? Do skeletal muscle cells experience them?

o   What are the three phases of an action potential?

o   What is an end plate potential? How is it related to an action potential in a muscle fiber?

·      LO 9.4.2 Follow the events of excitation-contraction coupling that lead to cross bridge activity.

o   What is excitation-contraction coupling, and how is it related to muscle contraction?

o   What are the four steps of EC coupling? Where in the skeletal muscle fiber does each step occur?

o   What are five types of ion channel involved in muscle fiber excitation and EC coupling? Where is each ion channel located and what stimulates each channel?

·      LO 9.4.3 Describe the steps of a cross-bridge cycle.

o   What is the purpose of the cross-bridge cycle?

o   What are the four steps of a cross bridge cycle?

o   What is triggered when ATP binds to the myosin head?

o   What is triggered when ATP hydrolysis occurs?

o   Which event of the cross-bridge cycle cannot occur in the absence of ATP? What is that condition called?

·      LO 9.5.1 Define motor unit and muscle twitch and describe the events occurring during the three phases of a muscle twitch.

o   What is the name for a skeletal muscle fiber’s tiny response to a single action potential?

o   What are the three phases of a muscle twitch?

§  What is a motor unit? How many motor neurons are involved in one motor unit? How many skeletal muscle fibers are involved in one motor unit?

§  Which molecular event is occurring inside a muscle fiber during the latent period of a twitch?

§  Which molecular event is occurring inside a muscle fiber during the contraction period of a twitch?

§  What happens to the muscle fiber during the relaxation period of a twitch?

·      LO 9.5.2 Explain how smooth, graded contractions of a skeletal muscle are produced.

o   How do individual muscle twitches contribute to larger muscle contractions that generate more tension?

o   What is summation? How does the frequency of motor neuron activation relate to summation?

o   How does simultaneous activation of motor units relate to the tension produced by a skeletal muscle?

·      LO 9.5.3 Differentiate between isometric and isotonic contractions.

o   In what way is an isometric contraction different than an isotonic contraction of a skeletal muscle? Provide a real-life example of each type.

o   What are the two types of isotonic contractions and how are they different?

·      LO 9.6.1 Describe three ways in which ATP is regenerated during skeletal muscle contraction.

o   What are the three main mechanisms for ATP regeneration in skeletal muscles?

§  What is an advantage of each mechanism?

§  What is a disadvantage of each mechanism?

o   Which two substrates are needed for ATP regeneration by direct phosphorylation? Which two products are created through this process?

o   Which sugar is needed for ATP regeneration by anaerobic metabolism?

o   Is oxygen required for ATP regeneration by aerobic metabolism? Which organelle is also needed?

o   Which mechanism for ATP regeneration will be dominant during each phase of exercise? First 6 seconds? Next 10 seconds? Next few minutes? Next minutes to hours?

·      LO 9.6.2 Define EPOC and muscle fatigue. List possible causes of muscle fatigue.

o   What does EPOC stand for?

o   What are four events happening in a person’s body while they experience EPOC?

o   What is muscle fatigue? How does it protect a person’s body?

o   What are two major causes of muscle fatigue?

·      LO 9.7.1 Describe factors that influence the force, velocity, and duration of skeletal muscle contraction.

o   What are four factors that can increase the force of a skeletal muscle contraction?

o   What are three factors that can increase the velocity and duration of a skeletal muscle contraction?

·      LO 9.7.2 Describe three types of skeletal muscle fibers and explain the relative value of each type.

o   What are the three types of skeletal muscle fiber? What two characteristics are used to organize the three types?

o   Which type contracts most quickly? Most slowly?

o   Which type fatigues most quickly? Most slowly?

o   Which type produces the most force? The least?

·      LO 9.8.1 Compare and contrast the effects of aerobic and resistance exercise on skeletal muscles.

o   What are three adaptations that will occur in response to endurance exercise?

o   What are five adaptations that will occur in response to resistance exercise?