Muscles, Part 1 - Muscle Cells: Crash Course Anatomy & Physiology #21

We're kicking off our exploration of muscles with a look at the complex and important relationship between actin and myosin. Your smooth, cardiac, and skeletal muscles create movement by contracting and releasing in a process called the sliding filament model. Your skeletal muscles are constructed like a rope made of bundles of protein fibers, and the smallest strands are your actin and myosin myofilaments. It's their use of calcium and ATP that causes the binding and unbinding that makes sarcomeres contract and relax. Pssst... we made flashcards to help you review the content in this episode! Find them on the free Crash Course App! Download it here for Apple Devices: https://apple.co/3d4eyZo Download it here for Android Devices: https://bit.ly/2SrDulJ Chapters: Introduction: Muscle Love 00:00 Smooth, Cardiac, and Skeletal Muscle Tissues 1:18 Structure of Skeletal Muscles 2:40 Protein Rules 3:25 Sarcomeres Are Made of Myofilaments: Actin & Myosin 3:54 Sliding Filament Model of Muscle Contraction 4:38 Review 9:17 Credits 9:57 *** Thanks to the following Patrons for their generous monthly contributions that help keep Crash Course free for everyone forever: Mark Brouwer, Jan Schmid, Steve Marshall, Anna-Ester Volozh, Sandra Aft, Brad Wardell, Christian Ludvigsen, Robert Kunz, Jason, A Saslow, Jacob Ash, Jeffrey Thompson, Jessica Simmons, James Craver, Simun Niclasen, SR Foxley, Roger C. Rocha, Nevin, Spoljaric, Eric Knight, Elliot Beter, Jessica Wode, David Rybka, Beth Larter, Damian Shaw, Randy Goldberg MD, Cynthia Krohn, Allison DeVoe, Brinae Lois Gaudet, Sara Bovi, Stephen DeCubellis, Travis Bell -- Crash Course is on Patreon! You can support us directly by signing up at http://www.patreon.com/crashcourse Want to find Crash Course elsewhere on the internet? Facebook - http://www.facebook.com/YouTubeCrashCourse Twitter - http://www.twitter.com/TheCrashCourse Instagram - https://www.instagram.com/thecrashcourse/ CC Kids: http://www.youtube.com/crashcoursekids