A journey through the mechanisms of muscles and muscular contraction. I begin by outlining the key structural elements of muscle cells, including the sarcolemma, sarcoplasmic reticulum, the myofibrils and their myofilaments. I then explain the sliding filament mechanism of muscle contraction, and how it is governed by neural signals through the release of calcium. I conclude with a brief overview of the types of muscle contractions, the difference between fast twitch and slow twitch muscle fibres, and a short discussion of some metabolic aspects of muscle function, including the role of creatine phosphate. Recommended pre-listening is Episode 26: Human Organ Systems. If you enjoyed the podcast please consider supporting the show by making a PayPal donation or becoming a Patreon supporter. https://www.patreon.com/jamesfodor https://www.paypal.me/ScienceofEverything