This is an introductory exercise for a section on muscle physiology. It consists of a worksheet that can be used in any one of a number of teaching/learning styles. It is intended as a formative assessment and is the first in a series. Extra credit/extension questions are included at the end for advanced students. A PowerPoint show version is also included if the teacher chooses to use guided discussion with the entire class; some extra resources and background information are included in the PowerPoint. Teacher's versions of the worksheet and PowerPoint are included with answers (worksheet) and extra background information and commentary (PowerPoint). The author's intent is to have a series of activities related to all three standards on muscle physiology.