Skin explained
Skin is a waterproof casing, a protection against bacteria, a cooling system and a sense organ. It is being made by two main layers, the dermis and the epidermis. Most frequent skin problems include eczema, adult acne, fungal infections, warts, dermatitis, skin cancer and sunburn.
The skin is the biggest organ in a human body. It is soft which helps movement, but still difficult enough to resist tearing or breaking. It varies in thickness and texture from a part of the body to another.
For example, the lips and eyelids skin is very soft and thin, while the sole skin on one’s feet is harder and thicker. The skin is a good reflection of general health. If someone is sick, it often reflected in their skin.
A Range of Functions:
Skin is one of our most versatile organs. Few of the various functions of skin include:
- A waterproof wrapping for the whole body
- The first line of defense against bacteria and other organisms
- A cooling system via sweat
- A sense organ that offers us information about pleasure, pain, temperature and pressure.
The Epidermis
The skin one can see is called the epidermis. This saves the more soft inner layers. The epidermis is made up of several cells sheets. The bottom sheet is where new epidermal cells are developed.
As dead skin and old cells are sloughed off the surface, new ones come up to replace them. The epidermis also carries melanin, the pigment that gives skin their color.
The Dermis
Underneath the epidermis is the dermis. This is made up of elastic fibres (elastin) for suppleness and protein fibers (collagen) for energy. The dermis carries sweat glands, hair follicles, sebaceous glands, nerves and blood vessels.
Glands and blood vessels
The dermis is well supplied with blood vessels. After exercise, in warm up session or in hot weather these blood vessels expand, bringing body heat to the skin surface. Perspiration floods out of sweat glands and evaporates from the skin, taking the heat along with it.
If the temperature is cold, these blood vessels in the dermis contract, which helps to lower the heat loss. Sebaceous glands in the dermis secrete sebum to lubricate the skin.
Hair and nails
Our lack of an entire cover of body hair makes human skin very different from any other animal skin. Hair is made up of a protein called keratin. The amount of body hair varies from place to place. Hairless sites include the palms, lips and feet soles.
The hairiest sites include the scalp, pubis and underarms in both sexes, and the face and throat in men. Nails are made from skin cells but the only live parts are the nail bed and the nail matrix just behind the cuticle. The nail itself is made of dead cells.
Nerves
Both the dermis and epidermis have nerve endings. These keep you informed on temperature, sensation (pleasure or pain) and pressure. Some areas have more of these nerves than others, like the fingertips for example.
Common Problems
Some common skin problems include:
- Adult acne – affected by hormones
- Dermatitis – inflammation of the skin, with number of various triggers
- Fungal infections – like tinea (athlete’s foot)
- Skin cancer – from long term exposure to the UV rays
- Sunburn – a radiation burn caused by UV rays
- Warts – caused by a virus
Where to seek help
- Your doctor
- Dermatologist
Things to remember
- Skin is the biggest body organ
- It is made up of two main layers, the dermis and epidermis
- Skin is a good indicator of common health.
