The heart is a muscle about the size of a fist, situated just to the left of the centre of the chest, behind the ribcage.
The heart has four chambers – two on the left side and two on the right, divided by a muscular wall called the septum. The two small upper chambers are called the atria and are responsible for collecting the blood that arrives in the heart via the veins. The two lower chambers are larger and are called the ventricles; these are responsible for pumping blood out of the heart via the arteries.
Oxygen and nutrients are delivered to every part of the body via blood from the left side of the heart, while carbon dioxide and waste products are carried back in the blood to the right side of the heart. This blood then goes from the right side of the heart to the lungs, where carbon dioxide is replaced with fresh oxygen before the blood is sent back to the left side of the heart.
The average adult body contains about 5 litres (9 pints) of blood, which the heart has to keep circulating all day, every day. Your heart beats about 100,000 times a day, pumping the equivalent of about 23,000 litres (40,500 pints) of blood around the 60,000 miles of blood vessels that make up your circulatory system. As the blood moves, it pushes against the sides of the blood vessels. Blood pressure is the force that blood puts on arteries and veins as it is pumped around the body.
Together, the heart and circulatory system make up the cardiovascular system.
What can go wrong?
Some people are born with hearts that have not developed properly before birth - this is called congenital heart disease. Sometimes you can inherit a heart condition from your family.
Some heart conditions may develop later in life. One of the main problems that can occur with the cardiovascular system is cardiovascular disease, where arteries become progressively narrowed and hardened due to a build up of fatty deposits (atheromas) within their walls. This process is known as atherosclerosis.
If this occurs within the arteries that provide oxygen-rich blood to the heart itself (the coronary arteries), the heart may not receive enough oxygen, leading to angina (chest pain or discomfort). This form of cardiovascular disease is known as “coronary heart disease” or “coronary artery disease.
If the coronary arteries become so severely narrowed that a blockage forms, the heart can be completely starved of oxygen, leading to a heart attack; this can permanently damage heart muscle and cause lifelong heart failure and even death.
If cardiovascular disease affects the arteries of the neck, blood supply to the brain can be interrupted and lead to a stroke.
So, what can we do to keep that marvelous little muscle healthy?
In Part 2, I discuss how you can reduce the risk of developing cardiovascular disease with some healthy changes to your lifestyle, and the role an osteopath can play in helping you maintain a healthy circulation.