The heart can continue to beat for days, even weeks or more, after an animal has died. The French Nobel laureate Alexis Carrel showed that a chick’s heart tissue, cultured on a medium of blood plasma and water, will pulsate for months and can remain alive for more than 20 years, much longer than the normal life span of its host. If the heart is the last major organ to stop working, it is also the first to develop—starting to beat, in humans, approximately three weeks into fetal life, even before there is blood to pump. From birth until death, it beats nearly 3 billion times. The amount of work it performs is mind-boggling. Each heartbeat generates enough force to circulate blood through approximately 100,000 miles of vessels. The amount of blood that passes through an average adult heart in a week could fill a backyard swimming pool.
—Adapted from Heart: A History, by Sandeep Jauhar, published by FSG
This article appears in the December 2018 print edition with the headline “The Beat Goes On.”