What actually causes the heart to pump?

romeomikegolf

Electrical signals from the brain causing the heart muscle to contract and relax. http://www.netdoctor.co.uk/hearthealth/howtheheartworks.htm Jan 11 13, 1:11 PM

tadpoles_uk

There is more to it than that. When the brain signals fail, the heart contracts on its own due to filling with blood. http://en.wikipedia.org/wiki/Cardiac_cycle Jan 11 13, 10:48 PM

sinty2

OK well we get electrolytes (sodium, potassium, chloride, and bicorbonate) from the food and water we eat/drink. Electrolytes basically become ions in solution and acquire the capacity to conduct electricity, this is essential for normal cell function and regulation of the heartbeat and the function of the muscles.The cardiac muscle is myogenic, meaning it has the property of being able to contract rhythmically independent of any nerve supply. The impulse to contract arises through spontaneous depolarisation in an area of tissue near the entry of the superior vena cava into the right atrium called the SA node (pacemaker of the heart). Jan 12 13, 9:36 AM