Skin optics Introduction Human skin is a multi-layered structure. It is generally divided into two layers, the epidermis and the dermis. Below the dermis a subcutaneous fat layer is found. The epidermis can be further divided into several sub-layers. These are the stratum corneum, the stratum lucidum, the stratum granulosum, the stratum spinosum, and the stratum germinativum. The stratum germinativum is usually referred to as the basal layer. Skin optics is the manner in which skin reflects and transmits light of different colors, or wavelengths, is determined by the inherent optical properties of the skin layers. Each of these layers has different inherent optical properties, primarily due to differences in the concentration …show more content…
A photon entering the skin will be scattered around by these particles therefore, be reflected from the skin in any direction with almost equal probability. This multiple scattering gives the skin its diffuse appearance. The reason for the white color of un-pigmented skin is that many of the skin particles have dimensions that are larger than, or as large as, the wavelengths of visible light. In that case the scattering efficiency does not vary strongly with wavelength. Had the skin particles been much smaller than the wavelengths of visible light, the skin would have appeared blue – just as light scattering by molecules in the air makes the sky appear blue. The scattering particles in the skin consist of either lipids or proteins embedded in the fluids in and between skin cells. These fluids mainly consist of water. The lipid scatterers are found in the stratum corneum, in the cell membranes, and in the intracellular particles. The most efficient scatterers with respect to both scattering probability and scattering angle are those with dimensions close to the wavelength of the incoming light.Thus, cells themselves, with dimensions of the order of 10 µm, scatter ultraviolet radiation much less efficiently
Anthropologists and geographers have studied and overtime come to the conclusion that distribution of skin color is not random. Darker skin color has been found to typically come from near the equator and lighter skin colors are typically coming from closer to the north and south poles. Over the years, researchers have found that darker skin colors has protected the skin from having skin cancer. Recent studies have shown that “skin color is the product of natural selection acting to regulate the effects of the sun’s ultraviolet radiation on key nutrients crucial to the reproductive success” (169).
To begin we will look at the integumentary system and its entire multitude of functions. The main components of the integumentary system are the skin, hair, nails, glands and nerves. For the purpose of this paper we will focus mainly on the levels of the skin and their functions. While the integumentary
Hair is considered one of the components of the integumentary system, along with the skin, nails, glands and nerves. Mammalian hair has many functions including protection from environmental factors and the ability to disperse sweat gland products such as pheromones. Almost every part of the human body is covered by hair except for the palms, hands and bottoms of the feet. On average, every person has about five million hairs; each of these hairs is born from a follicle or tiny tube-like structure that grows into the dermis layer of the skin. Oftentimes this follicle even reaches the subcutaneous layer, which is made of fat and connective tissue. (UXL Complete Health Research, 2001)
It is much thicker than the epidermis and contains collagen, reticular and elastic fibers, and is vascular. The area where the dermis meets the epidermis is unique in that the epidermis contains ridges at the stratum basale layer which interlocks with the dermal papillae, which are upward projections, like waves, on the uppermost surface of the dermis. The dermis had two sublayers. The papillary layer is in the dermal papillae and near it and is made up of areolar tissue. The reticular layer is dense irregular connective tissue that is found at the basal end of the dermis and contains collagen and adipose
Tanning can be harsh to your skin. The light coming from the sun contains different wavelengths of ultra violet (UV) waves. The two types of waves concerned about are UVA rays and UVB rays. UVA rays are long waves that cause more damage than a UVB ray. UVA rays penetrate deeper into your skin and cause tanning (“The Dangers of”). More and more exposure to UVA rays can cause permanent damage ...
Tanning affects the human skin through ultraviolet radiation, part of the spectrum of light that omits from the sun to the surface of the earth. Ultraviolet A rays are the longer ultraviolet rays that are projected, and these rays penetrate deep into the layers of skin, causing a tanning effect (Harvard Women's Health Watch, 2). It does this by penetrating into the lower layers of skin, or the epidermis, and triggering cells known as melanocytes to make melanin, the brown pigment that causes tanning (Hyde, Patrice, MD, 1). They account for most of the ultraviolet components emitted by lamps in tanning beds, because they are associated with an almost immediate tanning effect (Brady, Mary S, 2). The shorter rays are ultraviolet B rays, and these rays only reach the outer superficial skin cell layer, also known as the epidermis (Harvard Women's Health Watch, 2). UVB rays, therefore, are the actual cause of sunbur...
After production, melanin is packaged in membrane bodies called melanosomes. Dark skin has large melanosomes that are in a single state and also contains more melanosomes than lighter skin such as in Europeans. Most Asian skin, on the other hand, has smaller concentrated groups of melanosomes, whereas European skin has the smallest melanosomes, which are combined into bound materials. The spacing and amount of melanosomes are what gives the appearance of skin color due to the dispersal of light hitting the skin.
The second layer of the skin is called the dermis and is also known as the middle layer. The dermis is what holds the body together. The dermis has layers to it as well as the epidermis. There are two layers to the dermis, the papillary layer and the reticular layer. The cells of the dermis are fibroblast, macrophages, mast cells, and scattered white blood cells (wbc’s). the dermis is richly supplied with nerve fibers and BV;s. dermal BV’s is also a part of the integumentary system, dermal BV,s have converging and diverging vessels that ar...
The epidermis, which is the outer layer of the skin, is made up of four to five layers in some parts (Shier, Butler, & Lewis, 2009). In the majority of the areas, just four layers can be differentiated: the stratum basale, stratum spinosum, stratum granulosum, and stratum corneum (p.119). Another layer is the stratum lucidum which can be found in the thicker part of the skin of the palms and ...
Melanin helps reduce the absorption of wavelengths into the skin (Chaplin, Jablonski, 59). The more melanin in the skin, the greater the protection against harmful UV rays, and the amount of melanin in the skin correlates with the skin’s color (more melanin means darker skin)....
When light interacts with objects that are much smaller than the wavelength of the light, the light being scattered, rather than reflected. The electrons of such a small object are all shaken up and down at the same time by the electric field of the light wave, and they radiate that frequency of light in all directions. It turns out that the higher the frequency of the light, the more the light is scattered.
1. The colours would be adjusted to this type of skin( a wide variety of darker colours )
Light is what lets you experience colour. The pigment of the retina in your eyes is sensitive to different lengths of light waves which allows you to see different colours. The wavelengths of light that humans can see are called the visible colour spectrum.
Light passing through a medium such as air or water can be absorbed and scattered by the molecules in the medium or refracted by changes in air density. Earth's atmosphere contains air, water and dust molecules that cause light rays from the sun to change direction as they pass through slightly different densities of air - this is known as refraction. The amount of refraction of light is dependent on the refractive index (a measure of how much a substance bends light, dependent on its density and the type of molecules) and the incident angle at which the light enters the substance. Denser substances such as water will bend the light more than a less dense substance like air, and light entering a substance at an angle will refract more than entering perpendicular to the substance's surface. Air itself can have different indices- air that is warm will be less dense and so will refract light less.
The skin has 3 main function. It has to regulate body temperature, remove waste (perspiration), and protect. The skin is made up of 3 layers. The epidermis is the outer thinner layer of the skin that is made up of dead and living cells. The dermis is the thicker middle layer of the skin that contains blood vessels and nerves. Sweat glands are found in the dermis, they secrete perspiration through ducts to pores on the skin’s surface. To avoid problems like warts, boils, moles, acne, and sunburn you can wash your body daily, wear sunscreen that is 15 or higher, and check your body often...