Heartbeat & blood pressure

A heart beat is caused by altering contractions and relaxation of the myocardium. contractions are created by electrical impulses from the s-a node . An impulse from the s-a node causes the atrias to contact, forcing blood into the ventricles. .Following the contraction, the ventricles relax, and pressure falls. Blood flows into the atria and an impulse from the s-a start the cycle over.

As your heart beats it pumps blood around your body so that your muscles can get all the energy, it needs. To achieve this you heart pushes your blood through your arteries . As the blood goes through the arteries it pushes against the sides of these blood vessels. The strength of this pushing is called your blood pressure.