章节大纲

  • 常规

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  • 综合系统介绍

    lesson content

    Art for All Eras
    ::全伊拉斯艺术组织

    This is Maud Stevens Wagner, a tattoo artist who is pictured above in 1907. T attoos are not just a late 20th and early 21st century trend. They have been popular in many eras and cultures. Tattoos literally illustrate the biggest organ of the : the skin. The skin is very thin, but it covers a large area — about 2 m 2 in adults. The skin is the major organ in the integumentary system .
    ::纹身艺术家Maud Stevens Wagner是1907年的上图。纹身不只是20世纪末和21世纪初的趋势,它们在许多时代和文化中很受欢迎。纹身真实地说明了最大的器官:皮肤。皮肤非常薄,但覆盖大面积——成人约2平方米。皮肤是营养系统的主要器官。

    What Is the Integumentary System?
    ::什么是综合系统?

    In addition to the skin, the integumentary system includes the hair and nails, which are organs that grow out of the skin. Because the organs of the integumentary system are mostly external to the body, you may think of them as little more than accessories, like clothing or jewelry, but they serve vital physiological functions. They provide a protective covering for the body, sense the environment, and help the body maintain .
    ::除了皮肤外,内脏系统还包括毛发和指甲,这些指甲是皮肤生长的器官。由于内脏系统的器官大部分是身体外部的,所以你可能认为它们只是配件,如衣物或首饰,但能起到重要的生理功能。它们为身体提供防护,感知环境,帮助身体维持。

    The Skin
    ::皮肤

    The skin is remarkable not only because it is the body’s largest organ. The average square inch of skin has 20 , 650 sweat glands , and more than a thousand nerve endings. It also has an incredible 60 thousand pigment-producing . All of these structures are packed into a stack of cells that is just 2 mm thick, or about as thick as the cover of a book. Although the skin is thin, it consists of two distinct layers: the epidermis and dermis (as shown in the diagram ).
    ::皮肤之所以显著,不仅是因为它是身体最大的器官。 皮肤的平均平方英寸有20,650个汗腺和一千多个神经末端。 它也拥有6万种令人难以置信的颜料。 所有这些结构都被包装在一堆只有2毫米厚的或与一本书封面一样厚的细胞中。 虽然皮肤是薄的,但它由两层不同的层组成:皮层和皮层(如图所示 ) 。

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    The epidermis is the thinner outer layer of skin, and the dermis is the thicker inner layer of skin. The latter contains structures such as blood vessels and sweat glands.
    ::皮层是皮肤较薄的外层,皮层是较厚的皮肤内层,后者含有血管和汗腺等结构。

    Outer Layer of Skin
    ::皮肤外层

    The outer layer of skin is the epidermis . This layer is thinner than the inner layer (the dermis). The epidermis consists mainly of epithelial cells, called keratinocytes, which produce the tough, fibrous keratin . The innermost cells of the epidermis are cells that divide continuously to form new cells. The newly formed cells move up through the epidermis toward the skin surface, while producing more and more keratin. The cells become filled with keratin and die by the time they reach the surface, where they form a protective, waterproof layer. As the dead cells are shed from the surface of the skin, they are replaced by other cells that move up from below. The epidermis also contains melanocytes , the cells that produce the brown pigment melanin , which gives skin most of its color. Although the epidermis contains some sensory receptor cells — called Merkel cells — it contains no nerves, blood vessels, or other structures.
    ::皮肤的外层是外皮层。 这个层比内皮层(皮肤)更薄。 外皮主要由内皮细胞组成, 叫做乳腺细胞, 产生硬性、 纤维化的氯丁酸; 皮皮最深的细胞是不断分裂以形成新细胞的细胞。 新形成的细胞通过皮皮层向皮肤表面移动, 同时生产越来越多的氯丁烷。 细胞在到达表面时被填满了氯丁烷, 并在到达表面时死亡, 形成保护性、 防水层。 随着死亡细胞从皮肤表面脱落, 它们被从皮肤下面移动的其他细胞所取代。 皮皮皮层中还含有黑素, 产生棕色色色色色素的细胞, 其颜色大部分为皮质。 虽然上皮层含有感官感应体细胞, 叫做墨克尔细胞, 它没有神经、 血管或其他结构 。

    Inner Layer of Skin
    ::皮肤内层

    The dermis is the inner, thicker layer of skin. It consists mainly of tough connective tissue , and is attached to the epidermis by collagen fibers. The dermis contains many structures (as shown in the figure ), including blood vessels, sweat glands, and hair follicles , which are structures where hairs originate. In addition, the dermis contains many sensory receptors, nerves, and oil glands.
    ::皮肤是内层较厚的皮肤层,主要由坚硬的连接组织组成,通过凝固的纤维附着在皮层上。皮肤包含许多结构(如图所示 ) , 包括血管、 汗毛腺和毛囊, 它们是毛发发发发源的结构。 此外,皮肤包含许多感官受体、神经和油腺。

    Functions of the Skin
    ::皮肤的功能

    The skin has multiple roles in the body. Many of these roles are related to homeostasis. The skin’s main functions are  preventing loss from the body and serving as a barrier to the entry of microorganisms. Another function of the skin is synthesizing vitamin D , which occurs when the skin is exposed to ultraviolet (UV) light. Melanin in the epidermis blocks some of the UV light and protects the dermis from its damaging effects.
    ::皮肤在身体中具有多重作用。许多这些作用与软体保持有关。皮肤的主要功能是防止身体流失,并成为微生物进入的屏障。皮肤的另一个功能是合成维生素D,当皮肤暴露在紫外线(UV)光线下时就会发生。皮层中的某些紫外光中的梅兰因阻隔了紫外光,并保护皮肤免受其破坏作用。

    Another important function of the skin is helping to regulate body temperature. W hen the body is too warm, for example, the skin lowers body temperature by producing sweat, which cools the body when it evaporates. The skin also increases the amount of flowing near the body surface through vasodilation (widening of blood vessels), bringing heat from the body core to radiate out into the environment. The sweaty hair and flushed skin of the young man pictured reflect these skin responses to overheating.
    ::皮肤的另一个重要功能是调节身体温度。例如,当身体过热时,皮肤会通过产生汗来降低体温,在蒸发时会冷却身体。皮肤也会通过血管扩张(血管膨胀)增加在身体表面附近流动的数量,从身体核心带热到向环境辐射。照片中年轻男子的汗毛和冲洗皮肤反映了皮肤对过热的反应。

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    Both sweating and flushing of the skin are signs that the skin is working to cool the body.
    ::皮肤的汗水和冲洗都是皮肤为身体降温而工作的迹象。

    Hair
    ::毛发

    Hair is a fiber found only in mammals . It consists mainly of keratin-producing keratinocytes. Each hair grows out of a follicle in the dermis. By the time the hair reaches the surface, it consists mainly of dead cells filled with keratin. Hair serves several homeostatic functions. Head hair is important in preventing heat loss from the head and protecting its skin from UV radiation . Hairs in the nose trap dust particles and microorganisms in the air, and prevent them from reaching the lungs . Hair all over the body provides sensory input when objects brush against it, or when it sways in moving air. Eyelashes and eyebrows (see photo ) protect the from water, dirt, and other irritants.
    ::毛发只存在于哺乳动物体内,主要是氯丁二烯基脂细胞,每个毛发都生长在皮肤中的卵泡中,在毛发到达表面时,主要是用氯丁二烯填充的死细胞组成。毛发具有几种主理功能。头髮对于防止头部发热并保护其皮肤免受紫外线辐射影响十分重要。鼻部抓取灰尘微粒和微生物的气泡,防止它们进入肺部。全身的毛毛在物体刷过时或运动空气时都提供感官输入。目光和眉毛(见照片)可以防止水、泥土和其他刺激物的侵扰。

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    Eyelashes protect the eyes.
    ::眨眼保护眼睛

    Nails
    ::针甲

    Fingernails and toenails consist of dead keratinocytes filled with keratin. The keratin makes them hard but flexible, which is important for the functions they serve. Nails prevent injury by forming protective plates over the ends of the fingers and toes. They also enhance sensation by acting as a counterforce to the sensitive fingertips when objects are handled. In addition, the fingernails can be used as tools.
    ::指甲和脚趾甲由填满氯丁二烯的死乳腺细胞组成。 氯丁二烯使其硬而灵活, 这对于它们发挥作用十分重要。 指甲通过在手指和脚趾的端端上形成保护板来防止伤害; 也通过在物体被处理时作为对抗敏感指尖的抗力来增强感觉。 此外, 指甲还可以用作工具。

    Interactions with Other Organ Systems
    ::与其他机关系统的互动

    The skin and other parts of the integumentary system work with other organ systems to maintain homeostasis.
    ::皮肤和内脏系统的其他部分与其他器官系统合作,以保持自足状态。

    • The skin works with the immune system to defend the body from by serving as a physical barrier to microorganisms.
      ::皮肤与免疫系统一起工作,通过作为微生物的物理屏障来保护身体不受感染。
    • Vitamin D is needed by the to absorb calcium from food . By synthesizing vitamin D, the skin works with the digestive system to ensure that calcium can be absorbed.
      ::吸收食物中的钙需要维生素D。 通过合成维生素D,皮肤与消化系统合作,确保吸收钙。
    • To control body temperature, the skin works with the to either lose body heat, or to conserve it through vasodilation or vasoconstriction.
      ::为了控制体温,皮肤与失去体温或通过血管膨胀或血管收缩来保持体温有关。
    • To detect certain sensations from the outside world, the depends on nerve receptors in the skin.
      ::要探测外部世界的某些感觉 取决于皮肤的神经受体

    Summary
    ::摘要

    • The integumentary system consists of the skin, hair, and nails. Functions of the integumentary system include providing a protective covering for the body, sensing the environment, and helping the body maintain homeostasis.
      ::内脏系统由皮肤、毛发和钉子组成,内脏系统的职能包括:为身体提供防护,感测环境,帮助身体保持自足。
    • The skin consists of two distinct layers: a thinner outer layer called the epidermis, and a thi cker inner layer called the dermis.
      ::皮肤由两层不同的层组成:一层较薄的外层,称为皮层,另一层较厚的内层,称为皮层。
    • The epidermis consists mainly of epithelial cells called keratinocytes, which produce keratin. New keratinocytes form at the bottom of the epidermis. They become filled with keratin and die as they move upward toward the surface of the skin, where they form a protective, waterproof layer.
      ::上皮细胞主要包括称为乳腺细胞的上皮细胞,它们产生氯酸盐,在皮皮底部形成新的乳腺细胞,在皮肤上向皮肤表面移动时被填满并死亡,它们形成一个保护性、防水的层。
    • The dermis consists mainly of tough connective tissues and many structures, including blood vessels, sensory receptors, nerves, hair follicles, and oil and sweat glands.
      ::皮肤主要是硬性连接组织和许多结构,包括血管、感官受体、神经、毛囊、油和汗腺。
    • The skin’s main functions are  preventing water loss from the body, serving as a barrier to the entry of microorganisms, synthesizing vitamin D, blocking UV light, and helping to regulate body temperature.
      ::皮肤的主要功能是防止身体缺水,阻碍微生物进入,合成维生素D,堵住紫外线光,帮助调节体温。
    • Hair consists mainly of dead keratinocytes and grows out of follicles in the dermis. Hair helps prevent heat loss from the head, and protects its skin from UV light. Hair in the nose filters incoming air, and the eyelashes and eyebrows keep harmful substances out of the eyes. Hair all over the body provides tactile sensory input.
      ::毛发主要由死脊髓灰质细胞组成,在皮肤中生长。 毛发有助于防止头部发热,保护皮肤免受紫外线光的照射。 鼻腔过滤器中的毛毛进入空气,眼睫和眉毛使有害物质远离眼睛。 全身的毛都提供触觉输入。
    • Like hair, nails also consist mainly of dead keratinocytes. They help protect the ends of the fingers and toes, enhance the sense of touch in the fingertips, and may be used as tools.
      ::像头发一样,指甲也主要由死心细胞组成,它们有助于保护手指和脚趾的端部,增强指尖的触摸感,并可用作工具。

    Review
    ::回顾

    1. Name the organs of the integumentary system.
    ::1. 说明编组系统的各个机关。

    2. Compare and contrast the epidermis and dermis.
    ::2. 比较和对比皮层和皮层。

    3. Identify functions of the skin.
    ::3. 表明皮肤的功能。

    4. What is the composition of hair?
    ::4. 毛发的构成是什么?

    5. Describe three physiological roles played by hair.
    ::5. 描述毛发发挥的三个生理作用。

    6. What do nails consist of?
    ::6. 指甲包括什么?

    7. List two functions of nails.
    ::7. 列出钉子的两个功能。

    8. In terms of composition, what do the outermost surface of the skin, the nails, and hair have in common ?
    ::8. 就成分而言,皮肤、指甲和头发的最外层有什么共同之处?

    9. The innermost layer of the epidermis consists of _________ cells than the outermost layer of the epidermis.
    ::9. 上皮层最深层层由皮层最深层的细胞组成,而不是外皮最深层的细胞。

    a. older
    ::a. 年长

    b. younger
    ::b. 较年轻

    c. more  sweat glands
    ::c. 多出汗腺

    d. more blood vessel
    ::d. 更多的血管

     

    10. Identify two types of cells found in the epidermis of the skin. Describe their functions.
    ::10. 查明皮肤皮皮下发现的两类细胞,说明其功能。

     

    11. True or False:  Keratin-producing cells in the epidermis are a type of epithelial cell.
    ::11. 真实或假的:在皮皮下产生Keratin细胞是一种上皮细胞。

     

    12. True or False:  Vasodilation is used to warm the body.
    ::12. 真实的或假的:蒸发被用来温暖身体。

     

    13. Which structure and layer of skin does hair grow out of?
    ::13. 头发长出何种结构和皮肤层?

     

    14. Identify three main functions of the integumentary system. Give an example of each.
    ::14. 确定综合系统的三个主要功能,请举例说明其中的每一个功能。

     

    15. What are two ways in which the integumentary system protects the body against UV radiation?
    ::15. 营养系统以什么两种方式保护身体免受紫外线辐射?

    Explore More
    ::探索更多

    Tattoos have gained in popularity in Western cultures over the past several decades, but another form of skin art has been practiced from antiquity in West Africa and some other parts of the world. Called scarification, it involves cutting the skin to produce intricate patterns of scars that signify major life events, such as the attainment of adulthood. Watch this National Geographic video to learn more.
    ::纹身在过去几十年中在西方文化中越来越受欢迎,但另一种形式的皮肤艺术已经从西非和世界其他一些地方的古代中被实践。 被称为疤痕化,它涉及切割皮肤以产生复杂的疤痕模式,这些疤痕代表了重大的生活事件,如成年。 观看这个国家地理视频可以学到更多东西。

     

     

     

     

     

    You already know that a trip to the  beach could result in a nasty sunburn. Check out this video to learn more about the different types of sunscreen, and why they should be used daily: 
    ::您已经知道去海滩旅行会导致下流的晒伤。 看看这段视频, 了解不同种类的防晒霜, 以及为什么每天都要使用防晒霜: