• Question: How do we control the beating of our hearts when we don't think about telling our brain to make our heart eat??

    Asked by emilemon to Adam, Faye, Martin, Samantha on 23 May 2012.
    • Photo: Adam Bibbey

      Adam Bibbey answered on 23 May 2012:

      HI emilemon,

      Another great question, I guess you are interested in biology?

      The human heart actually creates its own beating rhythm. When a heart is removed from the body it will actually continue to beat on its own. It is caused by an electrical signal which begins in an area called the sinoatrial node. This then sends a signal to the atrioventricular node (also in the heart) which then spreads this electrical current along fibres (Purkinje fibres) causing the heart muscle (cardiac muscle) to contract, pumping blood out of the heart.

      This is repeated around 70 times per minute. The heart actually creates around 100 signals per minute if left alone but input from the brain (along nerves in the parasympathetic system) actually slow this down!

      Hope this helps πŸ™‚

    • Photo: Faye Didymus

      Faye Didymus answered on 26 May 2012:

      Hi emilemon! We have two different types of muscles in our bodies – voluntary and involtary. Our heart muscle is an example on an involuntary muscle so we don’t need to think about telling our brain to make it beat – it does it on it’s own! Cool, huh? πŸ™‚