RT Book, Section A1 Kandel, Eric R. A1 Koester, John D. A1 Mack, Sarah H. A1 Siegelbaum, Steven A. SR Print(0) ID 1192996818 T1 The Motor Unit and Muscle Action T2 Principles of Neural Science, 6e YR 2021 FD 2021 PB McGraw Hill PP New York, NY SN 9781259642234 LK accessbiomedicalscience.mhmedical.com/content.aspx?aid=1192996818 RD 2024/03/29 AB ANY ACTION—ASCENDING A FLIGHT of stairs, typing on a keyboard, even holding a pose—requires coordinating the movement of body parts. This is accomplished by the interaction of the nervous system with muscle. The role of the nervous system is to activate the muscles that provide the forces needed to move in a particular way. This is not a simple task. Not only must the nervous system decide which muscles to activate, how much to activate them, and the sequence in which they must be activated in order to move one part of the body, but it must also control the influence of the resultant muscle forces on other body parts and maintain the required posture.