It produces collagen and elastin to give skin its shape, plumpness and elasticity. It contains over 17 kilometres of blood vessels and millions of sweat glands regulate body temperature. It also houses sensitive nerve receptors which enable us to feel the environment around us.
The dermis also contains an army of immune cells allowing us to fight any pathogens, bacteria and viruses. Skin is considered as the first defence of your body. Although the structure remains the same across the body, the properties of the skin varies in different locations, for example you can probably tell there are differences between skin on your face, hands or back.
We also know that the skin contains a complex vasculature that serves multiple functions including nutrition and removal of waste products, regulation of body temperature, as well as the movements of immune cells.
what are the differences in the skin vasculature at different locations on the body?
This an interesting question because the skin has always been studied as one organ, but depending on its location, its structure and some proprieties differ.
It is very important to be aware of those differences to be able to better treat skin diseases that affect certain areas, e.g. conditions that are seen more commonly on the facial than the body skin.
Dr Clarisse Ganier is a Centre for Stem Cell & Regenerative Medicine (CSCRM) researcher studying the cells and structure of human skin. One of her areas of interest is the skin vasculature (the blood vessels that supply the skin) using a technology called optical coherence tomography.
To help see the differences in our skin, we are using a non-invasive imaging technology called Optical Coherence Tomography (OCT) which is a relatively novel method in the field of dermatology. The machine we use is an Angiographic-OCT which works by beaming safe, low-power infrared laser light through the top most layers of the skin to detect blood-flow motion as small as the width of a human hair.
WHAT IS OPTICAL COHERENCE TOMOGRAPHY?
3D Optical Coherence Tomography images from living human skin in the hand palm location.
3D Angiographic OCT images
(Source: Adapted from Wan, Ganier et al.2020).
Images a and b are OCT outputs showing the top layer of the skin (epidermis), with the dermis underneath it. The red colour running through the dermis is the blood flow that has been detected by the machine. In image c, the OCT has captured the skin of the palm from the top (as if you were looking at your palm) and shows the paths of blood flow underneath. Image d shows the bloodflow without any of the skin structure surrounding it, giving a 3D model of the vasculature of the palm skin.
By analysing these images, we have discovered that the skin vasculature has a distinct shape and structure depending on its skin location which could influence different skin conditions or how wounds heal. We are doing further investigations to understand why we have those differences.
Did you know that the human skin is the largest organ of the body?
An average adult has 2 square metres of skin, which makes up 16% of their body weight.