Please can you explain what a heart attack is and how it can occur?

The heart is an organ made of muscle in the centre of the chest. It's role is to pump oxygenated blood around the body to enable our functions to be carried out. During a heart attack, a section of the heart muscle dies as a result of its blood supply being cut off. This condition is also referred to as a 'myocardial infarction' in medical terms, with the word 'myocardial' meaning heart muscle, and 'infarction' meaning death of tissue due to a lack of oxygen. The heart's blood supply is usually delivered by small tubes branching off the heart called coronary arteries. These arteries can become blocked by fatty deposits which mainly come from our diet. If the coronary arteries become blocked, there will be a sudden reduction of oxygen to the heart which is needed for heart cells to function. As a result a part of the heart muscle will begin to die leading to a heart attack. [support this explanation by using a visual aid diagram of the heart's structure and the coronary arteries in relation to this].