A guide to the heart
Article date: 26 June 2014
Your heart is a powerhouse central to sustaining life, pumping 23,000 litres of blood around the body each day.
It is essential to take good care of it and ensure that it is working as effectively as possible as any cardiac problems have a huge effect on health.
The anatomy of the heart
Essentially your heart is a pump, beating about 100,000 times daily, or three billion times in an average lifetime, with each expansion and contraction propelling blood through a system of vessels.
Central to the cardiovascular system, it is located between your lungs and is around the size of a grapefruit or a human fist.
Roughly cone-shaped, the heart is situated slightly to the left of the sternum (breastbone) and under the ribcage.
The heart is a single hollow organ comprising four chambers, the upper two of which are called atria and the lower two ventricles. The atria collect blood and the ventricles pump it around the body.
Between the chambers is a series of one-way valves that close after blood flows through, with the movement creating the heartbeat noise.
Made of cardiac muscle, the heart operates as a double pump in that it sends oxygen-rich blood throughout the body and oxygen-poor blood to the lungs.
The left and right sides of the heart are divided by a wall of muscle tissue called the septum, with the left ventricle pumping harder than the right. This is why your pulse is felt more strongly on the left hand side of your chest.
A small group of cells in the heart called the sinoatrial node act as a pacemaker and ensure that the cardiac muscle in the heart beats at the same rate throughout the organ.
Damage to this part of the heart can affect the heart rate and an artificial pacemaker may be required to take over the role.
Three main types of blood vessel make up the cardiovascular system along with the heart. These are arteries, which carry oxygen-rich blood away from the heart, veins, which take blood full of waste products such as carbon dioxide back to the heart and the capillaries (small blood vessels connecting the arteries and veins).
The human body's network of blood vessels is around 60,000 miles long.
Superior and inferior vena cava
These are the two main veins attached to the heart. The superior vena cava is a wide vessel that carries deoxygenated blood from the upper part of the body to the heart, while the inferior vena cava carries deoxygenated blood from the lower half of the body to the heart.
The aorta is a large artery that carried oxygenated blood from the heart around the body.
The pulmonary artery carries blood from the heart to the lungs for it to be filled with oxygen.
The pulmonary vein is responsible for carrying oxygenated blood from the lungs into the heart for it to be pumped around the body.
The four valves of the heart
Between the four chambers of the heart are four valves that transport blood between them. They are central to the effective flow of blood through the organ and operate as one-way valves, restricting the flow of blood by opening and closing during contractions.
The four valves are called the tricuspid valve, the pulmonary valve, the mitral valve and the aortic valve, with their function controlled by a series of muscles and pressure differences within the heart.
How does the heart work?
The heart is essential for sustaining life and pumps constantly without rest. Cardiac muscle does not tire in the way that other muscle does and is only found in the heart.
By pumping oxygen-rich blood around the body and blood that has been depleted of oxygen to the lungs to be replenished and drop off carbon dioxide.
The right ventricle is responsible for pumping blood to the lungs and the left for pushing oxygen-rich blood around the body.
Heart rate is determined by the nervous system, with an average resting rate of around 70 beats per minute, rising to a maximum of around 220 beats per minute minus your age when you are anxious or take exercise.
The heart beats without you thinking about it as cardiac muscle operates involuntarily, with nerve cells in the brain telling it when to speed up and slow down.
Coronary arteries on the outside of the heart supply blood and oxygen to the heart itself to enable it to do its job.
In addition to transporting carbon dioxide to the lungs to be breathed out, blood also carries nutrients from the digestive system around the body, immune cells to fight disease and hormones from glands. Furthermore, waste products are taken through vessels to the liver and kidneys for processing.
How you can look after your heart
Sometimes described as the body's engine room, making sure your heart is healthy can have a hugely positive effect on overall wellbeing.
With all the essential functions the organ performs, it is of great concern that heart disease has been rising for the past century, with much of the problem attributed to changes in diet and lifestyle.
Some people are born with heart problems, known as congenital heart disease, but other issues can develop that can adversely affect the way the organ functions.
Taking care of the heart ensures that it remains healthy and does its job carrying oxygen around the body and removing carbon dioxide to be breathed out effectively.
A key way of ensuring your long-term heart health and protecting the organ is to eat a diet rich in fruit and vegetables, with low levels of fat, salt and sugar.
Smoking, drinking and stress can all have a negative effect on heart function and can lead to heart disease.
High blood pressure is another danger when it comes to looking after your heart and action should be taken to lower it where possible.
Taking regular exercise in order to raise your heart rate and give it a workout can improve its function, with studies showing those who are more physically active have a lower risk of developing cardiovascular disease than people with a more sedentary lifestyle. It’s widely recommended that you participate in 150 minutes of moderate intensity exercise each week, which can be broken down into five 30 minute sessions.
High cholesterol levels can also be linked to poor heart health and ensuring a balanced diet may assist in lowering them.
Being aware of the causes of cardiovascular disease and what can prevent it from developing, alongside the right support to achieve goals, can begin at any age and help to ensure your heart keeps beating strongly for many, many years.
Diabetes and family history can increase the risk of heart disease and those with close relatives affected or who are diabetics should take extra steps to protect their cardiovascular system.
Other ways of improving overall wellbeing and ensuring your heart is healthier are to manage your weight, eat oily fish regularly as it contains omega-3 fats to help protect against heart disease, get a health check and eat five portions of fruit and vegetables a day.
Coronary heart disease occurs when the heart's blood supply is blocked or interrupted as a result of fatty deposits building up in arteries.
An estimated 7.2 million people worldwide die each year as a result of heart disease. It is the biggest killer in the UK, causing an estimated 82,000 deaths annually.
With around one in eight women and one in five men dying from heart disease and 2.7 million people thought to be living with the condition, taking action to improve cardiovascular health can help to prevent it from developing.
Sufferers of heart disease have symptoms that can range from angina, or chest pain, to heart attacks and complete heart failure.