The human skin is the body’s outer covering and is the largest organ of the integumentary system. The skin has up to seven layers of ectodermal tissue guarding muscles, bones, ligaments, and internal organs. Human skin is similar to most other mammals’ skin, and it is very similar to pig skin. Though nearly all human skin is covered with hair follicles, it can appear hairless. There are two general types of skin, hairy and glabrous skin (hairless).
Because it interfaces with the environment, skin plays an important immunity role in protecting the body against pathogens and excessive water loss. Its other functions are insulation, temperature regulation, sensation, synthesis of vitamin D, and the protection of vitamin B folates. Severely damaged skin will try to heal by forming scar tissue. This is often discolored and depigmented. In humans, skin pigmentation (affected by melanin) varies among populations, and skin type can range from dry to non-dry and from oily to non-oily. Such skin variety provides a rich and diverse habitat for bacteria that number roughly 1000 species from 19 phyla, present on the human skin. Even though we have 7 and sometimes more layers, it all can be broken down into 3 basic layers which are.
The Epidermis: This is the outermost layer. In layman’s terms, if you scratch yourself and it doesn’t bleed, you only damaged this layer.
The Dermis: This is where the capillary blood vessels are along with the sweat ducts that travel through it. It is pink in color and contains most of the nerve endings, which is why damage here, like paper cuts, drives us crazy.
Subcutis/Hypodermis: This is where all of the blood vessels that carry blood to the capillaries are located. The fat and sweat glands are located here as well.
The actual skin color of different humans is affected by many substances, although the single most important substance determining human skin color is the pigment melanin. Melanin is produced within the skin in cells called melanocytes and it is the main determinant of the skin color of darker-skinned humans. The skin color of people with light skin is determined mainly by the bluish-white connective tissue under the dermis and by the hemoglobin circulating in the veins of the dermis. The red color underlying the skin becomes more visible, especially in the face, when, as a consequence of physical exercise or the stimulation of the nervous system (anger, fear), arterioles dilate.
The Fitzpatrick scale is a numerical classification schema for human skin color developed in 1975 as a way to classify the typical response of different types of skin to ultraviolet (UV) light:
I Always burns, never tans Pale, Fair, Freckles
II Usually burns, sometimes tans Fair.
III May burn, usually tans Light Brown
IV Rarely burns, always tans Olive brown.
V Moderate constitutional pigmentation Brown
VI Marked constitutional pigmentation Black
The function of the skin
1) Protection: an anatomical barrier from pathogens and damage between the internal and external environment in bodily defense; Langerhans cells in the skin are part of the adaptive immune system. Perspiration contains lysozymes that break the bonds within the cell walls of bacteria.
2) Sensation: contains a variety of nerve endings that react to heat and cold, touch, pressure, vibration, and tissue injury; see somatosensory system and haptics.
3) Heat regulation: the skin contains a blood supply far greater than its requirements which allows precise control of energy loss by radiation, convection and conduction. Dilated blood vessels increase perfusion and heat loss, while constricted vessels greatly reduce cutaneous blood flow and conserve heat.
4) Control of evaporation: the skin provides a relatively dry and semi-impermeable barrier to fluid loss. Loss of this function contributes to the massive fluid loss in burns.
5) Aesthetics and communication: others see our skin and can assess our mood, physical state, and attractiveness.
6) Storage and synthesis: act as a storage center for lipids and water, as well as a means of synthesis of vitamin D by action of UV on certain parts of the skin.
7) Excretion: sweat contains urea, however, its concentration is 1/130th that of urine, hence excretion by sweating is at most a secondary function to temperature regulation.
8) Absorption: the cells comprising the outermost 0.25–0.40 mm of the skin is almost exclusively supplied by external oxygen, although the contribution to total respiration is negligible. In addition, medicine can be administered through the skin, by ointments, or by means of an adhesive patch, such as the nicotine patch or iontophoresis. The skin is an important site of transport in many other organisms.
9) Water resistance: The skin acts as a water-resistant barrier so essential nutrients are not washed out of the body.
Oily skin is caused by overactive sebaceous glands that produce a substance called sebum, a naturally healthy skin lubricant. A high glycemic-index diet and dairy products (except for cheese) consumption increase IGF-1 generation, which in turn increases sebum production. Oily skin is typified by shininess, blemishes, and pimples. The oily-skin type is not necessarily bad, since such skin is less prone to wrinkling, or other signs of aging because the oil helps to keep needed moisture locked into the epidermis (outermost layer of skin). The negative aspect of the oily-skin type is that oily complexions are especially susceptible to clogged pores, blackheads, and the buildup of dead skin cells on the surface of the skin.
Sunblock and sunscreen
Sunblock and sunscreen are different. Sunblock is opaque and stronger than sunscreen, since it is able to block most of the UVA/UVB rays and radiation from the sun and does not need to be reapplied several times in a day. Titanium dioxide and zinc oxide are two of the important ingredients in sunblock.
Sunscreen—Sunscreen is more transparent once applied to the skin and also has the ability to protect against UVA/UVB rays, although the sunscreen’s ingredients have the ability to break down at a faster rate once exposed to sunlight, and some of the radiation is able to penetrate to the skin.
Vitamin A, also known as retinoids, benefits the skin by normalizing keratinization, downregulating sebum production which contributes to acne, and reversing and treating photodamage, striae, and cellulite.
Vitamin D is used to downregulate the cutaneous immune system and epithelial proliferation while promoting differentiation.
Vitamin C is an antioxidant that regulates collagen synthesis.
Vitamin E is a membrane antioxidant that protects against oxidative damage and also provides protection against harmful UV rays.
Care for skin
The skin supports its own ecosystems of microorganisms, including yeasts and bacteria, which cannot be removed by any amount of cleaning. Despite these vast quantities, all of the bacteria found on the skin’s surface would fit into a volume the size of a pea. In general, the microorganisms keep one another in check and are part of healthy skin. When the balance is disturbed, there may be an overgrowth and infection, such as when antibiotics kill microbes, resulting in an overgrowth of yeast.
Cosmetics should be used carefully on the skin because these may cause allergic reactions. Each season requires suitable clothing to facilitate the sweat’s evaporation. Sunlight, water, and air play an important role in keeping the skin healthy.
Exfoliating the skin is key to keeping it healthy. How often depends on your own skin type, thickness, age, and type of exfoliator method utilized. I exfoliate every 3 days and that seems to work for me but please use your own judgement.
Cleansing the skin before bed should be disciplined and methodical. We all need to cleanse it at least once a day. I wash mine twice, am and pm. I utilize a battery powered rotary brush in am. and a woven cloth type while in the shower at night. As you progress in your transition, you will actually go through a mild puberty stage, and acne is part of that process. Keep your skin as clean and dry as possible to avoid blackheads and scarring. Use a mild soap with cloth and hot water to open pores, there is a lot of debate on the vacuum devises to clean out the pores of your face. If you do, utilize it directly after the wash while pores are still open, then close the pores with cold water splashes before using creams and/or Collagen on your face.
As skin ages, it becomes thinner and more easily damaged. Intensifying this effect is the decreasing ability of the skin to heal itself as a person ages. Among other things, skin aging is noted by a decrease in volume and elasticity. There are many internal and external causes of skin aging. For example, aging skin receives less blood flow and lower glandular activity. Cortisol causes the degradation of collagen, accelerating skin aging. Anti-aging supplements containing retinol and collagen are used to treat skin aging.
Please remember to read all documentation accompanying any supplemental products that you’re going to use for your skin. There is so much more to write here i.e. Tattoos, burns, cuts, and the list goes on and on. I hope this condensed version helped you take care of the largest organ of your body. For the M2F’s, there is a benefit that the Estradiol gives us for our skin making the care of it easier to maintain our skin.
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