1.3 皮肤疾病和疾病 -- -- 高级
章节大纲
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What happens if skin grow too quickly?
::如果皮肤长得太快会怎样?Normally, skin cells grow gradually and flake off about every four weeks. New skin cells grow to replace the outer layers of the skin as they shed. But in psoriasis, new skin cells move rapidly to the surface of the skin in days rather than weeks, resulting in thick, red skin with flaky, silver-white patches called scales.
::通常情况下,皮肤细胞会逐渐生长,大约每四个星期就会消散一次。 新的皮肤细胞会随着皮肤外层的脱落而生长,以取代外层的皮肤。 但在微丝虫病中,新的皮肤细胞会在几天内而不是几周内迅速迁移到皮肤表面,导致厚红皮肤,上面有薄薄的银白斑块。Homeostatic Imbalances of the Skin
::皮肤的自制性不平衡Many wavelengths of electromagnetic radiation are emitted by the sun: some we can see, and others we cannot. The range of wavelengths of radiation we can see is called visible light. However, visible light makes up only a small portion of the total radiation that comes from the sun. Two other types of radiation that you have probably heard about before include infrared and ultraviolet radiation. Infrared light is the thermal energy , or the “heat rays,” that you feel when the sun shines on you. The other, ultraviolet (UV), which we have discussed a little already, helps the body produce vitamin D , but it can also damage in skin cells. Our main source of UV radiation , the sun, is shown in Figure .
::许多电磁辐射波长是由太阳释放的:有些我们可以看到,有些我们看不到。我们可以看到的波长辐射波长称为可见光。然而,可见光光只占太阳辐射总量的一小部分。你可能听说过另外两类辐射,包括红外线和紫外线辐射。红外线光是热能,或“热光线 ” , 当太阳照耀你时你感觉到的。另一个紫外线(紫外线),我们已经讨论过一点,帮助身体生产维生素D,但它也可能损害皮肤细胞。我们的紫外线主要辐射源,太阳,在图中显示。Ultraviolet radiation emitted by the sun. Prolonged exposure to UV radiation can lead to skin cancer and premature wrinkling of the skin.
::太阳发射的紫外线辐射,长期接触紫外线辐射可能导致皮肤癌和皮肤过早皱纹。Beneficial Effects of UV Radiation
::紫外辐射的有益影响A positive effect of ultraviolet radiation (UV) exposure is that it causes the production of vitamin D in the skin. It has been estimated that tens of thousands of premature deaths occur in the United States annually from a range of cancers due to vitamin D deficiency.
::紫外线辐射(UV)照射的一个积极影响是导致皮肤产生维生素D,据估计,美国每年有成千上万人因维生素D缺乏引起的一系列癌症而过早死亡。Ultraviolet radiation has other medical applications in the treatment of skin conditions such as psoriasis, a disorder in which red, scaly patches form due to an overproduction of epithelial cells, and vitiligo, a condition that causes loss of pigment, which results in irregular, pale patches of skin, as shown in Figure .
::紫外线辐射在皮肤病治疗中还有其他医疗用途,如皮质丝虫病,这种病症中,由于上皮细胞的过度生产而形成红色、刺青的斑块,以及维蒂里戈病,造成颜料流失,造成不规则的、苍白的皮肤斑块,如图6所示。Vitiligo is a chronic skin condition that causes loss of pigment, resulting in irregular pale patches of skin. The cause of vitiligo is not fully understood. There is some evidence suggesting it is caused by a combination of auto-immune, genetic, and environmental factors. Phototherapy, in which the patient is exposed to long-wave ultraviolet (UVA) light from the sun or from UVA lamps, used together with certain medicines can help in many cases.
::维蒂里戈是一种慢性皮肤病,造成色质丧失,导致不规则的皮肤苍白斑块,维蒂里戈的原因没有完全被理解,有些证据表明,它是由自动免疫、遗传和环境因素综合作用造成的。 照片治疗,即病人接触太阳或UVA灯的长波紫外线(UVA)光,与某些药物一起使用,在很多情况下都有帮助。Harmful Effects of UV Radiation
::紫外辐射的有害影响In humans, prolonged exposure to solar UV radiation may result in acute and chronic health effects on the skin, , and immune system . While some sunlight is good for health, skin cancer caused by excessive exposure to sunlight is not among the sun's benefits. Because some types of skin cancer are easy to cure, the danger posed by too much sunlight is perhaps not taken seriously enough. It is important to remember that a more serious form of skin cancer called melanoma is also associated with excessive sun exposure. Melanomas are potentially lethal tumors .
::在人类中,长期接触太阳紫外线辐射可能会对皮肤、免疫系统和免疫系统造成急性慢性健康影响。虽然某些阳光对健康有益,但过度接触阳光造成的皮肤癌并不是太阳的好处。由于某些种类的皮肤癌容易治愈,过多的阳光造成的危险可能不够严重。重要的是要记住,一种叫作乳腺瘤的更为严重的皮肤癌也与过度接触太阳有关。 美拉诺马是潜在的致命肿瘤。The UV radiation excites DNA molecules in skin cells, causing bonds to form between neighboring thymine bases, producing a thymine dimer that changes the shape of the DNA helix. These dimers can lead to . Mutations are changes to the base pair sequence of DNA or . Mutations can result in cancerous growths.
::紫外线辐射刺激皮肤细胞中的DNA分子,导致相邻的甲状腺基体之间形成联系,产生一种改变DNA螺旋形状的胸膜薄膜。这些硬币可以导致。变异是DNA基对序列的变化或。变异可能导致癌症增长。Skin cancer is an increasingly common condition. This is due in part to peoples’ increased exposure to UV radiation, because of the increased popularity of sun bathing. Because melanin protects the skin from the effects of UV radiation, lighter-skinned people are at more risk of developing skin cancer than darker-skinned people are. However, the risk of developing skin cancer is related to the amount of sunburn and the overall length of time a person has been exposed to UV light. The three most common types of skin cancers are shown in Figure .
::皮肤癌越来越常见,部分原因是人们越来越多地接触紫外线辐射,因为太阳浴越来越受人欢迎。 由于梅兰宁保护皮肤免受紫外线辐射的影响,皮肤皮肤较皮肤较皮肤较黑的人更有可能患皮肤癌。 但是,皮肤癌的发病风险与太阳晒伤量和一个人受到紫外线照射的总时间长度有关。 三种最常见的皮肤癌类型见图。The three most common forms of skin cancer. Basal cell carcinoma (left), squamous cell carcinoma (center), and melanoma (right). All three types arise from cells in the epithelium.
::最常见的三种皮肤癌形式是:巴萨细胞癌(左),基细胞癌(中位)和黑皮瘤(右位),这三种类型都来自上皮的细胞。As a defense against UV radiation, the body tans when exposed to moderate levels of radiation by releasing the brown pigment melanin. This helps to block UV penetration and prevent damage to the vulnerable skin tissues deeper down. Suntan lotion, often referred to as "sun block" or "sunscreen," partly blocks UV and is widely available. Most of these products contain a sun protection factor (SPF) rating that describes the amount of protection given. This protection, however, applies only to a type of UV radiation called UVB rays—the type of radiation that is responsible for sunburn. UVA rays, another type of UV radiation, penetrate more deeply into the skin and may be responsible for causing and wrinkles. Some sunscreens now include compounds, such as titanium dioxide, which help protect against UVA rays. Other UVA blocking compounds found in sunscreen include zinc oxide and avobenzone. Another means to block UV radiation is sun protective clothing, as shown in Figure . This is clothing that has an ultraviolet protection factor (UPF) rating that describes the protection given against both UVA and UVB radiation.
::作为防范紫外线辐射的一种防护措施,在通过释放棕色色色素而暴露于中等辐射水平时,身体会晒黑;这有助于阻止紫外线穿透,防止对皮肤组织造成更深的损害;日光乳液,通常被称为“太阳块”或“太阳屏”,部分封隔紫外线,广泛使用;这些产品中的大多数含有太阳保护系数(SPF),描述所提供的保护量;然而,这种保护仅适用于一种被称为紫外线的紫外线——这种辐射是造成日晒的。紫外线是另一种紫外线,这种辐射更深入地穿透皮肤,并可能引发和皱纹。有些日光膜现在包括化合物,例如二氧化钛,有助于防范紫外线。在防晒中发现的其他紫外线封堵化合物包括氧化锌和avobenzone。如图所示,阻止紫外线辐射的另一种手段是防晒衣服。这是紫外线保护系数(UPFF),说明对紫外辐射的防护。Some good advice from the National Cancer Institute. The risk of developing melanoma and other forms of skin cancer can be significantly reduced by avoiding excessive exposure to the sun, using sunscreen lotions, and wearing protective clothing to shield the skin from ultraviolet radiation.
::国家癌症研究所提供了一些良好的建议,通过避免过度暴露于太阳、使用防晒霜洗涤剂、穿防护服保护皮肤免受紫外线辐射,可以大大减少患染黑瘤和其他形式的皮肤癌的风险。Acne
::丙烷The most common form of acne is known as acne vulgaris, which means "common acne." Many teenagers get this type of acne. Acne is a highly complicated and variable form of skin infection. It affects more than 85% of teenagers, but frequently also continues into . For most people, acne tends to decrease or disappear after one reaches his or her early twenties. Excessive secretion of sebum from the sebaceous glands leads to the plugging of the hair follicle with dead skin cells (corneocytes). This blockage is caused by a failure of the normal process in which skin cells that line the pores are usually shed. Within these blocked pores, and yeast begin to multiply. In response to the bacterial and yeast , the skin inflames, which produces a red bump.
::许多青少年患上这种腺炎。 肾炎是一种非常复杂和易变的皮肤感染形式。 它影响超过85%的青少年,但也经常持续。 对于大多数人来说,在一个人到达20岁早期后,丙烯往往会减少或消失。 塞巴塞的腺体中过多的渗漏导致毛囊与死皮肤细胞(角形细胞)的塞合。 这种阻塞是由于正常过程的失败造成的,正常过程是将毛孔排在皮肤细胞中,通常在皮肤细胞中排出。在这些被堵的孔中,酵母开始增加。在细菌和酵母中,皮肤发炎,导致红肿。Summary
::摘要-
Positive effects of UV exposure include the production of vitamin D and medical applications such as the treatment of skin conditions like psoriasis and vitiligo.
::紫外线照射的积极影响包括生产维生素D和医疗应用,如治疗皮肤病,如psorpic和vippiligo。 -
Prolonged exposure to solar UV radiation may result in acute and chronic health effects on the skin, eyes, and immune system. Melanoma is an example.
::长期暴露于太阳紫外辐射可能会对皮肤、眼睛和免疫系统造成急性和慢性健康影响。 -
Acne is a highly complicated and variable form of skin infection.
::Acne是一种非常复杂和多变的皮肤感染形式。
Review
::回顾-
How can UV rays lead to cancer?
::紫外线如何导致癌症? -
What causes acne?
::是什么导致丙烯? -
The SPF rating on sunscreen protects against which types of UV rays?
::防晒霜上的SPF评级保护哪类紫外线?
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Positive effects of UV exposure include the production of vitamin D and medical applications such as the treatment of skin conditions like psoriasis and vitiligo.
