The Heart - Our First Organ

Subscribe to Naked Science - http://goo.gl/wpc2Q1 Every other Wednesday we present a new video, so join us to see the truth laid bare... Three weeks into your pregnancy one of the first recognisable organs to form is the heart. Without a heart there is no way of spreading around the food and oxygen the embryo needs to flourish. Until now the heart has been a dormant clump of muscle cells, but after 22 days it bursts suddenly into life when still just the size of a poppy seed. One cell spontaneously contracts, triggering its neighbours, and setting off a chain reaction, until all the heart cells are beating. Later on, when the nervous system is more developed, the brain will carefully control the rate of contraction, keeping it steadily beating and pumping for the rest of the child’s life. If he lives to 75, that will be 2.75 billion heart beats. Clip from the award winning documentary “In the Womb”. Watch it here - http://youtu.be/0gAsdEUNUJY