Get to know your body’s most important muscle -- your heart -- and learn how to take your own pulse! ---------- Like SciShow? Want to help support us, and also get things to put on your walls, cover your torso and hold your liquids? Check out our awesome products over at DFTBA Records: http://dftba.com/SciShow Or help support us by becoming our patron on Patreon: https://www.patreon.com/scishow ---------- Looking for SciShow elsewhere on the internet? Facebook: http://www.facebook.com/scishow Twitter: http://www.twitter.com/scishow Tumblr: http://scishow.tumblr.com Instagram: http://instagram.com/thescishow SOURCES: http://www.chop.edu/pages/how-normal-heart-works#.VbbE30JViko http://www.nhlbi.nih.gov/health/health-topics/topics/hhw/contraction