Through a series of exquisite ink and watercolour illustrations, ‘Anatomicum’ shows how our organs, tissues, blood vessels, nerves and cells are working together to make us who we are. In this extract, illustrator Katy Wiedemann and author Jennifer Z Paxton uncover some of the incredible things going on under our skin.
Our bodies inside out
Words by Jennifer Z Paxtonartwork by Katy Wiedemann
- In pictures

The study of the body’s structure – called anatomy – provides the basis for all of our medical understanding. The word comes from the ancient Greek anatome, meaning ‘to cut up’. It has been studied since the earliest recorded periods of history, as long ago as 1600 BCE. The immune system, shown here, is a collection of organs, tissues and cells that work to defend the body from harmful bacteria or substances that do not belong.

Providing the framework for the entire human body is the skeleton. This hard but flexible scaffold gives us our overall shape, supports the muscles, protects the body’s soft inner organs and constantly manufactures new blood cells. The skull is a protective home for the brain and the eyes, ears, nose and tongue. Although it appears to be a single bone, it is in fact formed of 22 individual bones.

There are over 300 joints in the body, with every bone connected to at least one other (except the hyoid bone in the throat). There are three different types. Fibrous or immovable joints serve the important function of holding bones together for stability. Slightly more flexible are the cartilaginous joints, where a layer of cartilage sits between the bones and joins them together. By far the most common are the moveable, or synovial, joints, including the hip, knee, shoulder and elbow.

From the cautious first steps of a baby finding its way in the world to the speed of an Olympic athlete, the muscular system is responsible for producing every possible kind of movement. Over 40 muscles lie under the skin of our face, which joins to the bones of the skull. They work together in many combinations, allowing us to produce approximately 10,000 different facial expressions, vital for our interaction and communication with others.

We breathe over 10,000 litres of air each day to keep our cells alive and healthy. Once air enters the lungs, it begins a journey through a dividing network of more tubes that become smaller and smaller as they travel deeper into the organ. Eventually the air reaches tiny closed sacs called alveoli. There are several hundred million alveoli in an adult’s lungs, meaning they have a huge surface area in order to quickly transfer as much gas as possible.

Also part of our cardiovascular and respiratory system, a huge network of tubes called blood vessels lets blood travel to every part of our body. Laid end to end, this vascular network would measure over 120,000 kilometres – long enough to circle the globe three times. Within this network, arteries carry blood away from the heart, veins carry blood towards the heart, and capillaries join the two together.

The liver carefully orchestrates hundreds of processes to keep the blood clean and the body healthy. As the largest organ inside the body, it sits in the upper right region of the abdomen, just under the ribcage and diaphragm. It is roughly triangular in shape, with four different parts, or lobes. The liver receives over 10 per cent of all the blood in the body at any one time, and pumps an astonishing 1.5 litres of blood through it every minute.

All but the most simple animals have a nervous system, and humans possess the most advanced one we know of. Despite making up just 3 per cent of our overall body weight, the brain uses about 20 per cent of the body’s energy – much more than any other organ. This enormous demand for power is because the brain controls everything we do, from movement and breathing to thoughts, emotions and memories.
‘Anatomicum’ is out now.
About the contributors
Jennifer Z Paxton
Jennifer Z Paxton is Lecturer in Anatomy at the University of Edinburgh and Principal Investigator of the Paxton Lab, a tissue engineering laboratory. Jennifer has won the Wellcome Trust 'I'm a Scientist' competition twice (2013, 2018). She loves bringing the science of anatomy to a wider audience and working with primary schools to engage more children with the subject.
Katy Wiedemann
Katy Wiedemann is an illustrator and tattoo artist in Philadelphia, USA. Her work explores the field of scientific illustration, particularly that of human and animal anatomy. Working in ink and watercolour, Katy uses traditional techniques to realise her blend of realism and scientific understanding, and to highlight the beauty and complexity of our biological forms.