Basics of Skin Anatomy and Physiology (Part One)
All About Wounds (Part Two)
Basics of Wound Assessment (Part Three)
Dynamics of Wound Healing (Part Four)
The objective of this series is to equip persons with knowledge to identify a wound at different stages and to understand the importance of intervention; such that, when said intervention is not implemented, it can cause more harm than good.
For all types of wounds, please ensure that you consult a doctor to treat that specific wound. The information in this blog is not meant to replace medical advice nor be interpreted as medical advice.
With that being said, let’s start with our first instalment –
Basics of Skin Anatomy and Physiology
Basics of Skin Anatomy
The skin is the largest organ in the body. It makes up 16% of your total body weight. It is the body’s first line of defence. The skin is made up of:
- Epidermis (top layer)- This is made up of dead skin. Its main function is protection
- Dermis (mid layer)- Has hair roots, sweat glands, nerves, blood vessels
- Subcutaneous (fat) layer – This is the anchor for the skin. Gives warmth and stores energy
- Accessory structures (hair, nails, sweat gland)
Blood Supply
The skin receives its blood supply through blood vessels that originate in the underlying muscle. The arteries branch into smaller blood vessels and then into even smaller vessels called capillaries, forming a network that goes up to the dermis and subcutaneous layer.
Understanding the blood supply will allow you to understand why some wounds bleed more than others do. It also indicates the amount of blood that can escape from a wound and thus significantly reduce the total blood in your body’s circulation. This will then determine the level of urgency needed to treat such a wound.
Basics of Skin Physiology
The skin performs various vital functions. Damage to the skin impedes the ability to carry out these vital functions. Let’s have a look at what some of these functions are:
Protection
The skin is a physical barrier against microorganisms and other items not desired in the body, ultimately protecting the body against infection. It also protects the tissues underneath from mechanical injury and it provides protection from loss of water, electrolytes and other substances inside the body.
When the skin is broken, that protection is compromised and can cause harm to many systems within the body.
Sensory Perception
The skin contains nerve endings that allow you to feel pain, pressure, heat, and cold to identify potential dangers and avoid injury. For persons with decreased nerve ending functionality, such as diabetic patients, this function can be lost in affected areas, making it easier to become inadvertently injured.
Thermoregulation
As the skin comprises nerves, blood vessels and endocrine glands in the dermis layer, the skin controls body temperature. It can cause blood vessels to reduce blood flow to conserve heat by constricting the blood vessels when the surroundings or the body is cold and dilate them to increase sweat production when the surroundings or body is hot.
Excretion
The skin transmits small amounts of water and body waste (small items the body does not want retained within) through small pores to the outside world. Through your sweat, you excrete waste products. This process also allows the skin to maintain thermoregulation and balance of water and electrolytes.
Metabolism
Minerals are essential to the body. The skin helps maintain the mineralization of bones and teeth. It also synthesizes Vitamin D when exposed to sunlight – Vitamin D is essential to the metabolism of Calcium and Phosphate.
Absorption
The skin allows for the absorption of some drugs directly into the bloodstream.
Looking at all the functions of the skin, we can see how important it is to identify when skin integrity is compromised with a wound, and getting it assessed by a doctor to implement the correct treatment for healing.
As we age, the skin goes through degenerative changes that may affect the usual functions of the skin as well as the risk of wound development and reduce the ability for the skin to heal. Let’s look at some of these changes.
Skin Thickness
There is a decline in the thickness of the skin, which reduces the level of protection the skin can provide. The subcutaneous layer contains fewer fat cells in the elderly, so the ability to keep warm is also reduced.
Reduced Vascularity
This causes reduced blood flow to the skin, which in turn reduces the nourishment and the ability of the skin to function at an optimal level
Reduction of Special Cells
Melanocytes decrease, causing pigmentation irregularities, which increases the risk of skin cancer and Mast cells decline, reducing the inflammatory response – a process that entails fighting bacteria and other harmful elements in a specific area of the body.
In an earlier blog “Main factors that cause falls in the elderly”, we saw how easy it could be for the elderly to fall. Falls are a direct cause of wounds in the elderly that is why it is so important to protect them from falls as their chances of recovery are greatly disadvantaged by the natural process of ageing. Read the blog http://niceusgeriatric.com/2021/08/31/main-factors-that-may-cause-falls-in-the-elderly/ to get some tips on how to keep your elderly loved one safe from falls.
Next week we look at different wound types and classifications. Until next time!