About Your Skin
Would you like to learn more about how your skin works and how you can take good care of it? Eva has put together several short, informative articles for you to read. After you have absorbed these general facts about skin, you can use the Self-Assessment Exercise to take a critical, educated look at your own skin, and can consider in what areas you might like Eva's assistance.
A Brief Tour of the Skin
Most of the aesthetic endeavors in Eva's practice concern our skin, the interface between our bodies and the world. If you have a basic understanding of skin structure, you will be able to understand how and why different aesthetic techniques work.
Skin is a large sensory organ that transmits neural messages about touch, pressure, pain, and temperature. It is part of the integumentary system, which also contains nails and sweat and oil glands. Its primary and critical function is to provide a protective barrier between our bodies and external materials, both organic and inorganic. It also helps to regulate body temperature and to minimize evaporative fluid loss. The pigment of the skin provides protection from ultraviolet light (UV). Vitamin D is synthesized on exposure to short-wave UV light.
The skin is comprised of three main layers:
- The epidermis, the outermost layer.
- The dermis (stratum corium), the central layer.
- The hypodermis (subcutaneous layer), the bottom layer.
(Note that people in the aesthetics industry sometimes use “mesoderm” to denote the combined dermis and hypodermis, although technically the term means “middle layer.” In biology, the term refers to the germ layer between the ectoderm and the endoderm in a developing embryo. This layer eventually develops into connective tissue, muscle, bone, and the urogenital and circulatory systems, as well as the entire dermis (skin). “Mesoderm” used in our specialty has only the first meaning.)
The translucent epidermis in turn contains several cell layers. The outer stratum corneum, or horny layer, consists of flattened, rough, dead cells like fish scales. These keratinized squames shed, and are replaced by new cells that are formed in the stratum germinativum, the deepest epidural layer, and then migrate up to the surface. In addition to keratinocytes, this layer contains melanocytes, the pigment-producing cells. A glowing complexion results primarily from a moist epidermis from which most of the rough outer cells have been removed (exfoliated).
The dermis is the workhouse of the skin. It is tough and resilient due to its support of interlaced fibrous tissue. It contains blood and lymph vessels, sensory nerves, sweat glands and ducts, sebaceous (oil) glands, and hair roots, bulbs, and follicles. The erector pilli in this layer are small muscles that contract in response to cold, pulling the follicles upright (goose bumps). Eccrine sweat glands produce sweat; apocrine sweat glands are responsible for natural odor; unpleasant body odor results from organisms that live on moist skin.
The deep hypodermis binds the skin to the body and provides cushioning and insulation, as well as a storage repository for fat. It contains fibrous connective tissue, fat (adipose cells; subcutaneous fat), and blood vessels.
Melanin, carotene, and hemoglobin all contribute to skin color. Melanosome pigment is produced by melanocytes and is the primary determinant; located in each cell, it darkens (“tans”) when exposed to UV radiation (primarily sunlight) and also protects the cell. It is the size of the melanosome granules, rather than the quantity, that determines the degree to which skin is “black” or “white.” Hemoglobin — the iron-containing protein of red blood cells — adds pink color from oxygenated blood in the dermis. Carotene, found in the dermis and hypodermis, is the orange pigment in vegetables such as carrots and sweet potatoes; it is most visible in thick skin, such as on the palms of the hands.
The dermis is composed largely of the structural protein collagen. These molecules form cablelike strands and network sheets that provide support to skin and internal organs, and connect soft-tissue structures to the skeleton. Most dermal collagen forms horizontal bundles held together by elastin fibers and surrounded by hyaluronic acid. Fibroblast cells in the dermis produceboth collagen and elastin fibers. Glycoproteins hold water in the dermis; hyaluronic acid’s water-retaining abilities plump the skin and keep it moist and supple. As we age, production of collagen, elastin, and hyaluronic acid declines; subcutaneous fat thins; and facial muscles lose strength and volume (atrophy). The result is a loss of elasticity and of ability to maintain hydration. Add gravity and motion, and the skin sags and wrinkles.
The deeper parallel collagen bundles are thick and tough. They may rupture if they are stretched significantly, causing stretch marks. When the skin is injured (grazed or cut, for example), it heals itself by forming new collagen. Excess collagen may cause scars that are too large (hypertrophic) or lumpy (keloids).
Subcutaneous fat pillows, or lobules, are separated by collagen. If the lobules grow large (store excess fat), they can become visible as dimpling, or cellulite (dermatomyoliposclerosis; DMLS). Cellulite is most likely to form where the skin is bonded firmly to the muscles, such as on the buttocks and thighs. It is a normal, genetically determined condition. Mild cellulite is visible only when the skin is compressed (pinched gently); moderate cellulite is visible on only a standing person. Fully developed cellulite is visible all the time.
When the triple-helix collagen molecule is heated, it unwinds and the chains separate, destroying the network structure. The cooled collagen soaks up water and forms gelatin. Hydrolyzed collagen protein, used as a dietary supplement, is animal collagen that has been broken down by enzymes into more-readily digestible, short amino-acid chains.
I hope that you find this information useful and appropriate. If you have any questions, please do not hesitate to contact me or schedule an appointment.
Best,
Eva Sztupka
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