Skin Anatomy & Function:
A Western Medical Perspective
Before we can properly care for our skin, it is important to understand how it functions. Without understanding the biology of the skin we are at risk of doing the wrong things, combining too many active ingredients, or doing nothing at all. Traditional skincare involved categorizing skin into 4 subtypes - oily, dry, normal/sensitive, and combination - and treating accordingly. However the current emergence of precision based skincare and innovative ingredients aims to address far more targeted physiologic and cosmetic concerns. The best way to know what products are right for your skin is to understand what is happening beneath the surface.
- At roughly 3000 square inches (give/take, depending on your size), the skin is the largest organ of the body
- Skin is several layers deep and includes:
- Finger/toe nails
- Sweat glands
- Sebaceous (oil) glands
In Western medicine, 7 distinct layers of skin are identified and grouped into three main groups:
- Hypodermis (Subcutaneous Layer)
Each of these 3 main layers serves different crucial roles when it comes to our internal and external health, which affects the radiance and clarity of our skin.
Epidermis: Anatomy & Function
- Consists of top 5 layers
- Stratum corneum
- Stratum lucidum
- Stratum granulosum
- Stratum spinosum
- Stratum basale (Basement membrane)
- Keeps bacteria out both mechanically and chemically by way of special immune cells (MICROBIOME), thus protects from infection
- Keeps moisture in
- Melanocytes produce melanin which are responsible for giving skin its color
- A disruption in the function of melanocytes can cause hyperpigmentation - dark spots/patches - (or hypopigmentation - light spots) often a skin complaint
- New skin cells are made here
- Protects from external environment (think wind, sun, flying objects)
- The epidermis becomes thinner as we age, becoming more thin, dry, and flaky
Dermis: Anatomy & Function
- Provides skin a natural thickness, or fullness
- Is responsible for heat regulation
- Composed of collagen and elastin
- Allows skin to stretch then resume its original shape
- With age, the production of collagen and elasten diminishes leading to more “droopiness,” “jowls”, wrinkles, sunken eyes, and loose skin - despite exercise and/or weight loss
- Within the dermis you will find:
- Nerve receptors
- Connective tissue
- Vascular tissues
- Sebaceous (oil) glands
- Hair follicles
Hypodermis: Anatomy & Function
- Bottom-most layer of skin comprised of fat (adipose) tissue and well vascularized connective tissue
- Supports the top layers of the skin
- Provides insulation and padding
- Protects underlying tissues and organs from trauma
- Prevents heat loss
- Acts as reserve source of energy
- Home to excess fat most people are concerned with when losing weight
- Excess adipose leads to obesity and health problems
Treatment for Skin Disorders
Depending on the skin condition, various topical and systemic medications can be used to treat and clear the disease and/or manage the symptoms.
- Corticosteroids: reduce immune system activity, swelling, itching, and redness and improve dermatitis (an umbrella term for any inflammatory skin condition). Steroids are often used. They are available over-the-counter (hydrocortisone cream) or various prescription preparations.
- Antibiotics: treat bacterial infections such as cellulitis, acne, rosacea, impetigo
- Antiviral Drugs: Suppress activity of viruses (they do not eliminate the virus) such as herpes and shingles
- Antifungal Drugs: topical or oral medications that treat fungal infections such like athletes foot or other yeast infections
- Antihistamines: oral or topical medications that block histamine, a substance that causes itching
- Skin surgery
- Used to remove skin cancers, large infections, or other growths
- Reduce symptoms of dry skin which is more prone to irritations and break down.
The health of our skin is affected by more than just what we put on it. The environment has an enormous impact on the skin’s elasticity and luster. For instance, pollution, sun exposure, extreme temperatures, or climate conditions (ie: wind) will rapidly degrade the integrity of the epidermis. As we age, it takes longer and becomes more difficult to repair and regenerate damaged tissue, therefore creating an aged appearance earlier in life.
Lifestyle factors are also known contributors to early aging: smoking, excessive alcohol intake, a poor diet (excessive or inadequate), and improper hygiene. These habits play a key role in the process of oxidation which is a precursor to aging and, in some cases, some forms of cancer. Antioxidants are popular because they combat the effects of oxidation; however avoiding the trigger is far better than trying to do damage control later.
In conclusion, to best care for your skin it is important to first understand what makes it tick. Skin care trends and ingredient du jour’s change with the wind, but if you comprehend the fundamentals of anatomy and physiology, you will be able to discern which products to take home and those to leave on the store shelf.