The subject of ‘Medicine’ is incredibly broad. The National Health Service, which is the publicly funded health care system in the UK, is one of the largest employers in the world, employing approximately 1.5 million people. Of these staff, slightly over half are clinical professionals (doctors, nurses, midwives and more), who have either specialist or generalist roles in providing health care within the UK.

For an insight into some of the clinical roles that healthcare professionals provide in the UK, and an introduction to how a student who studies Medicine progresses from their theoretical studies to being a practicing doctor, watch the video below.


One of the many areas that doctors can specialise in is Cardiology. Cardiologists are experts on the cardiovascular system, which includes the heart and blood vessels. It is worth noting that Cardiologists, alike many medical professionals, work exclusively on adult patients – doctors trained to work with patients under 18 years are Paediatric Cardiologists.

The structure of the heart

In order to diagnose and treat diseases of the heart, it is important to understand how the heart functions in a healthy state. The heart pumps blood around the body in two systems. First, the systemic system pumps blood from the left side of the heart, through the brain and other organs, to ensure they receive oxygen. As the blood supplies oxygen to organs, the blood becomes deoxygenated. Secondly, the pulmonary system pumps blood from the right side of the heart to the lungs, in order to resupply the blood with oxygen (make the blood oxygenated).

A diagram of the heart is shown here – the areas shown in red are places where blood is oxygenated, and areas shown in blue are places where the blood is deoxygenated. Notice the arteries (blood vessels that take blood away from the heart) and veins (blood vessels that bring blood back to the heart) are named as belonging to one of the two systems: systemic or pulmonary.

“OpenStax AnatPhys fig.19.6 – Surface Anatomy of the Heart – English labels” by OpenStax, license: CC BY. Source: book ‘Anatomy and Physiology’,

A 3D model of the exterior of a human heart is shown below. The model has 18 labels on it, which correspond to the diagram above. Using this model and the diagram above, work out on the 3D model where oxygenated and deoxygenated blood exists.

“3D model human heart” by Bluelink Anatomy – University of Michigan, © B. Kathleen Alsup and Glenn M. Fox, license: CC BY-NC-ND. Captured and edited by: Madelyn Murphy, Will Gribbin

Once you have located each part of the heart, watch the video below on ‘the structure of the heart’ to find out the function of each of these parts, and make brief notes on what each part of the heart does.

Cardiovascular disease

Understanding the function of the heart in a healthy state helps to inform doctors of the likely causes when the heart doesn’t function as it should. Cardiovascular disease is a term used to refer to any kind of failure of the cardiovascular system. Types of Cardiovascular disease include:

  • Coronary heart disease. This occurs when the heart does not receive oxygenated blood, due to the blood flow to the heart being blocked or reduced. Coronary heart disease can lead to chest pain (angina), heart attacks and heart failure.
  • Stroke. When the supply of oxygenated blood to the brain is blocked or reduced, a stroke occurs. Stroke can lead to brain damage and potentially death. A ‘mini-stroke’, caused by a temporary disruption in blood flow to the brain, is called a transient ischaemic attach (TIA).
  • Peripheral arterial disease. If arteries carrying oxygenated blood from the heart to peripheral limbs become blocked, this can lead to a dull or cramping pain, numbness or weakness in the limbs, hair loss and/or persistent open sores (called ulcers). Typically, this condition affects the legs.
  • Aortic disease. The Aorta is the largest blood vessel in the body, sending blood from the left side of the heart to the rest of the organs and brain. Aortic diseases affect the aorta – a common example Is aortic aneurysm, where the artery muscle becomes weaker, bulging outwards. This can be life-threatening if the bulge bursts.

Many of the types of cardiovascular disease listed above are caused by blockages to the cardiovascular system. So, how can the cardiovascular system become blocked? A common cause is a condition caused atherosclerosis. Atherosclerosis is a build up of fatty deposits (called plaques) in a blood vessel, which both narrow the diameter of the vessel (meaning less blood can pass through), and also make the blood vessel stiffer, and more likely to become blocked, leading to blood clots which can block the blood flow to the brain, heart, or other organs. You can see a 3D rendering of atherosclerosis in the image to the side of this paragraph.

Given how dangerous atherosclerosis is, you can imagine that doctors are keen to treat and prevent this occurring in patients. We currently do not know the exact reasons why blood vessels accumulate fatty plaques, but a few risk factors are known, including:

  • Smoking (risk increases)
  • Diet (risk increases with a high-fat, unhealthy diet)
  • Exercise (risk increases with less exercise)
  • Weight (risk increases if you are clinically overweight or obese)
  • Alcohol (risk increases if you drink large amounts, regularly)

Here, we have focussed on the risk factors that are within your control (e.g. ‘Age’ is another risk factor, but since you cannot change this we haven’t included it here). This is because we do not currently have any treatments that can reverse atherosclerosis, therefore, controlling the development of atherosclerosis is the main way that doctors can help patients. In order to do this, doctors work to educate people about the ways to live more healthily, and decrease their risk of developing atherosclerosis and cardiovascular disease.

Medical Ethics

The importance of educating the public about health, highlights another important aspect of working as a doctor: communicating and working with people. Working in healthcare, doctors need to have both an in depth understanding of science, and also a drive to help people. Doctors hold a place of trust in the eyes of the public, and it is important that they therefore work in the public interest at all times, putting their patients first.

In order to achieve this, medical practice is founded in four key pillars of ethics: autonomy, beneficence, non-maleficence and justice. The short videos below each summarise one of these pillars of ethics – watch the videos to find out more about each of these topics, and how these principles translate into medical practice.





Every decision in medical practice should be guided by these principles. However, as the videos allude to, sometimes it can be hard to know how to best apply these principles. It is important to consider each case carefully, as when these pillars of ethics are not followed, it can lead to increased suffering of, injury to or even death of patients.

Below, there are four brief (3-5 minute) articles or reports, relating to a recent medical decision. Some of these articles demonstrate the application of the four pillars of ethics, and some illustrate what happens when one or more of these pillars is not properly applied. Read each article, and ask yourself:

  1. Which pillar(s) of medical ethics do you think are most relevant here?
  2. Is the subject of this article ethical, according to your understanding of medical ethics?

Finally, many doctors go above and beyond for their patients! For example, Robert Parry, M.D., FACS, director of Paediatric General Surgery at Akron Children’s Hospital, adds something special to the experience of each child he operates on. For each post-surgery bandage, he draws a picture of a character the child loves to personalise their bandage and make it look more ‘friendly’. He has done this for over 10,000 children!

Going Further

As part of educating people, the NHS has its own YouTube channel, where you can find videos on lots of aspects of healthcare, and information about the NHS. NHS – YouTube

Dr Ana Wallis
Dr Ana Wallis

Ana is Project Lead for the Post-GCSE Inspire Programme, and competed her DPhil (PhD) at Oxford, where she examined how our genetic material (DNA) is copied when a cell divides.