If you're seeing this message, it means we're having trouble loading external resources on our website.
If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.
Unit 11: Musculoskeletal system physiology and disease
About this unit
Learn how our muscles work from the cellular level to executing a kick or a dance move. Discover how our brain tells muscle to contract, and how that helps us respond to changes in temperature or even a lion chasing us