This chapter presents the muscular system. In conjunction with the skeletal system, the muscular system serves to move the body.
The chapter introduces the three types of muscle; the major events in contraction of skeletal, smooth, and cardiac muscles; the
energy supply to muscle fiber for contraction; the occurrence of oxygen debt; and the process of muscle fatigue (objectives 1,
3, 4, and 10). The chapter describes the structure and function of a skeletal muscle, distinguishes between a twitch and a
sustained contraction, explains how various kinds of muscle contraction produce body movements and maintain posture, shows
how the location and interaction of muscles produce body movements, identifies the location and action of major skeletal
muscles, and differentiates the structure and function of a multiunit smooth muscle and a visceral smooth muscle (objectives 2,
5-9, 11, and 12).
The skeletal system can be thought of as the passive partner in producing movement; the muscular system can be thought of as
the active partner. This chapter explains how muscles interact with bones to maintain posture and produce movement. In
addition, it tells the characteristics and functions of skeletal, smooth, and cardiac muscles. This knowledge is a foundation for the
study of other organ systems, such as the digestive system, the respiratory system, and the cardiovascular system.
After you have studied this chapter, you should be able to:
Describe how connective tissue is part of the structure of a skeletal muscle.
Name the major parts of a skeletal muscle fiber and describe the function of each part.
Explain the major events that occur during muscle fiber contraction.
Explain how energy is supplied to muscle fiber contraction, how oxygen debt develops, and how a muscle may become
Distinguish between fast and slow muscle fibers.
Distinguish between a twitch and a sustained contraction.
Describe how exercise affects skeletal muscles.
Explain how various types of muscular contractions produce body movements and help maintain posture.
Distinguish between the structures and functions of a multiunit smooth muscle and a visceral smooth muscle.
Compare the contraction mechanisms of skeletal, smooth, and cardiac muscle fibers.
Explain how the locations of skeletal muscles help produce movements and how muscles interact.
Identify and locate the major skeletal muscles of each body region and describe the action of each muscle.
How do muscle cells utilize energy and interact with bones to accomplish such diverse movements as playing a piano and playing
a basketball game?