Describe the three types of muscular tissue. Describe the physiological properties that all muscle types have in common. List the defining characteristics of skeletal muscle. Discuss the possible elastic functions of the connective tissue components of a muscle. Describe the structural components of a muscle fiber. Relate the striations of a muscle fiber to the overlapping arrangement of its protein filaments. Name the major proteins of a muscle fiber and state the function of each. Explain what a motor unit is and how it relates to muscle contraction. Describe the structure of the junction where a nerve fiber meets a muscle fiber. Explain why a cell has an electrical charge difference across its plasma membrane and, in general terms, how this relates to muscle contraction. Explain how a nerve fiber stimulates a skeletal muscle fiber. Explain how stimulation of a muscle fiber activates its contractile mechanism. Explain the mechanism of muscle contraction. Explain how a muscle fiber relaxes. Explain why the force of a muscle contraction depends on sarcomere length prior to stimulation.