Breathing rates impact on heart rate?

Question

I know that the respiratory and circulatory system go hand in hand and influence each other.

When we breathe rapidly, chances are that our heart rate is also higher. When we breathe slowly, our heart rate slows down.

How can this be explained more in depth? I mean does breathing stimulate something which changes your heart rate? Is it just how much oxygen your body is receiving?

Basically I would like to know in more detail what is actually happening in the body when your breathing rate is low or high and how this goes hand in hand with the heart's rhythm.

Thanks

Answer 1

http://en.wikipedia.org/wiki/Heart_rate

Try that link. I hope it helps b/c it's complicated.

Answer 2

Your respiratory rate is either determined voluntarily (you control the rate knowingly) or involuntarily. For the former, the rate is based on the amount of Carbon Dioxide in the body--the more there is, the faster the resp. rate.

When you breath excessively fast (tachypnea) for relatively long periods of time, however, less oxygen enters the blood stream via the lungs because there is simply not enough time for the exchange the carbon dioxide for oxygen in the alveoli before the air is expelled back out. Therefore, the blood is less oxygenated. In order to compensate for this, the heart beats faster so that the same rate of oxygen can be delivered to the bodies cells so that they can stay alive.

Oxygen is needed by the cells because it is the final hydrogen acceptor in the Electron Transport Chain (the H+ ion is an electron). The gas is needed for the cells take in energy and therefore stay alive.