How is your skin made?
Know its structure and functions. Know Your Skin

The skin is the largest organ of the body and is made up of multiple layers of cells   that are constantly going through self shedding and regeneration once every 30 days. The skin is made up of 3 main layers: Epidermis, Dermis and Subcutaneous or hypodermis. These layers are held together by the protein, collagen and elastin fibres. Collagen provides durability and strength. Time taken for deepest layer to come to the top is 45-75 days.

Epidermis

The epidermis is the outer layer of skin. The thickness of the epidermis varies in different types of skin. It is the thinnest on the eyelids at .05 mm and the thickest on the palms and soles at 1.5 mm.

The epidermis contains 5 layers. From bottom to top the layers are named:

• stratum basale
• stratum spinosum
• stratum granulosum
• stratum licidum
• stratum corneum

The bottom layer, the stratum basale, has cells that are shaped like columns. In this layer the cells divide and push already formed cells into higher layers. As the cells move into the higher layers, they flatten and eventually die.

The top layer of the epidermis, the stratum corneum, is made of dead, flat skin cells that shed about every 2 weeks

Specialized Epidermal Cells

There are three types of specialized cells in the epidermis.

• The melanocyte produces pigment (melanin)
• The Langerhans' cell is the frontline defense of the immune system in the skin
• The Merkel's cell's function is not clearly known

Dermis

The dermis also varies in thickness depending on the location of the skin. It is .3 mm on the eyelid and 3.0 mm on the back. The dermis is composed of three types of tissue that are present throughout - not in layers. The types of tissue are:

• collagen
• elastic tissue
• reticular fibers

Layers of the Dermis

The two layers of the dermis are the papillary and reticular layers.

• The upper, papillary layer, contains a thin arrangement of collagen fibers.
• The lower, reticular layer, is thicker and made of thick collagen fibers that are arranged parallel to the surface of the skin.

Specialized Dermal Cells
The dermis contains many specialized cells and structures.

• The hair follicles are situated here with the erector pili muscle that attaches to each follicle.
• Sebaceous (oil) glands and apocrine (scent) glands are associated with the follicle.
• This layer also contains eccrine (sweat) glands, but they are not associated with hair follicles.
• Blood vessels and nerves course through this layer. The nerves transmit sensations of pain, itch, and temperature.
• There are also specialized nerve cells called Meissner's and Vater-Pacini corpuscles that transmit the sensations of touch and pressure.

Subcutaneous Tissue

The subcutaneous tissue is a layer of fat and connective tissue that houses larger blood vessels and nerves. This layer is important is the regulation of temperature of the skin itself and the body. The size of this layer varies throughout the body and from person to person.

The skin is a complicated structure with many functions. If any of the structures in the skin are not working properly, a rash or abnormal sensation is the result. The whole specialty of dermatology is devoted to understanding the skin, what can go wrong, and what to do if something does go wrong.

These are fat cells that conserve body heat while protecting other organs from injury. They provide a cushioning effect and are a source of energy in lean times.

Thickness of layer varies - the thinnest layer is on our eyelids making them light and flexible, the thickest is on our hands and feet for gripping.

Functions of Skin

This skin provides a protective layer for organs and tissues from pathogens, heat and light. It regulates body temperature. It stores water, fat and Vitamin D and has touch receptors that sense pain or pleasure. Skin is an excretory and absorption organ.

Skin has a natural moisturising factor (NMF). Teen skin is prone to oiliness as hormones are regulating. At 20-30 years skin cell turnover provides optimum condition. At 30-40 years cell turnover starts to decrease and fine lines start to appear. At 40-50 years skin becomes more dry. Over 50 years of age, cell turnover drops by 50% resulting in flaky patches and deeper lines.

The skin may be sensitive. Sensitive skin reddens easily due to environmental changes or cosmetic products. Skin can become permanently sensitive due to allergy, shaving, and use of skin care productscontaining alpha hydroxy and retinoic acid skin.

Skin has several jobs

• It holds the body together
• It stops water and body fluids from leaking out of the body.
• It stops germs and dirt from getting into the body.
• It senses how things feel (touch).
• It can sense the temperature of things.
• It can tell you when you have been hurt (pain).
• It is waterproof so that rain slides off.

TYPES OF SKIN

Skin can be divided into various types according to its texture. It is essential to know the various types of skin, so that  its treatment can be done accordingly.

• Normal skin
• Dry skin
• Oily skin
• Combination skin
• Sensitive skin

Normal Skin

It has a fine even texture with a supple and smooth surface. It has a proper balance between oil and moisture contents and is therefore moist and neither greasy nor dry. It looks clear and does not develop spots and blemishes. The pores of the skin are fine and barely visible. It reflects good health and needs gentle treatment.

Dry skin

Dry skin has a dry parched appearance and has a tendency to flake easily. It is prone to wrinkles and lines. It is due to the inability to retain moisture as well as the insufficient production of sebum by  the sebaceous glands. Dry skin often has problems in cold weather and ages faster than normal or oily skin. Constant protection is very important. It needs a moisturiser during the day and a good cream at night.

Oily skin

This type of skin is caused by the over secretion of sebum making the skin surface oily. The excess oil on the surface of  the skin attracts dirt and dust from the environment. oily skin is also prone to black heads, white heads, spots, pimples and such skin will never be clear. This type of skin needs to be cleansed thoroughly.

Combination skin

This type of skin is very common. As the name suggests, it is a combination of both oily and dry skin with certain areas of the face oily and the rest dry. Usually there  is a Central greasy panel consisting of the forehead, nose and  chin and a dry panel consisting of cheeks and the areas around the eyes and mouth. The greasy central panel is referred to as T - Zone. In such cases, each part of the face should be treated accordingly - the dry areas as for dry skin and the central panel as for oily skin.

Sensitive skin

This type of skin has a fine texture and is very sensitive to changes in the climate. They show the disadvantage of bleaching, Waxing, threading etc.

Choosing Your Skin Type

The best way to get the most out of your natural skin care products is to choose them on the basis of your skin type.

There are four basic skin types: oily, normal, dry and sensitive. When it comes to the skin of the face and neck, most people have a combination of two or more of these, so when choosing your skin care products consider how each product is going to affect your skin.

How to choose your skin type

Problems and tests

Take the tests to see if you have any problems with your skin

Test No.1

Run a pencil over your cheeks and neck with gentle force, if this results in reddening or swelling, you have very sensitive skin.

Test No.2

Press a small mirror against various parts of your face, if you have a dry skin, only a very slight touch of grease will show on the mirror surface, With combination skin, more grease will show when using the mirror on the middle part of the face. Greasy skin is recognizable by obtaining greasy spots from the cheeks.