Muscles support the body's skeleton and allow for voluntary movements. Muscles also allow for the many involuntary movements that support the body, such as the beating heart and the contraction of the stomach. The large amount of ATP required for muscle movement is provided by cellular respiration in the cells.
The oxygen required for cellular respiration is provided by the respiratory system, as is the expulsion of carbon dioxide as a waste product.
As you work through this unit and its module, you will find Self-Check questions, labs, and critical thought questions. There will be lesson goals indicated at the beginning of each lesson and then clearly identified throughout the lesson.