Question

How can the heart beat when it is outside of the body?

Answer 1

Hint: The heart is a vital organ which pumps blood through the body, and is part of our body's circulatory system. It is made up of muscles and the heart muscle is special because of what it does.

Complete answer:
The reason our heart survives outside is because it is not regulated by the brain. That is our heart does not need a brain, or body to keep beating. It is known that our brain determines how slow or fast our heart rate is, but it doesn’t actually control the heart beat. Everything needed to make the heart work is right within the heart itself. Heart is controlled by the muscles which are present in its structure that regulate the contraction and relaxation.
Heart contains AV and SA nodes, these nodes regulate its normal activity. The heart has its own electrical system that makes it to beat and to pump blood. Heartbeats are sparked by our own natural pacemaker which is found within the heart. Without this, our brain would have to send signals to the heart to trigger every beat. Instead, electrical impulses in our heart are triggered by the SA node or sinoatrial node. These impulses travel along the walls of our right and left atrium. Stimulating the top part of our heart to contract which, in turn, pumps the blood to ventricles. The SA node still sends impulses throughout the organ, even after our heart is disconnected from our body, allowing it to pump. Because of this, the heart continues to beat for a short time even after brain death, or after being removed from the body. As long as it has oxygen, the heart will keep beating. This continues, about 3 to 5 minutes, until the cells run out of energy.

Note: With the help of doctors and an ice box, our heart can survive outside of the body up to 4 hours. Because, it gets fed with the nutrients and the cold temperature keeps it from beating and from wasting energy. Once the heart starts to warm back, it starts beating like normal.