SKIN AND THE INTEGUMENTARY SYSTEM CHAPTER 6 This chapter describes the skin and its appendages.

SKIN AND THE INTEGUMENTARY SYSTEMCHAPTER 6This chapter describes the skin and its appendages. It explains the structure and function of the layers of skin (dermis and epidermis) and the hair, nails, and sweat glands. This chapter also explains how the skin helps regulate body temperature and how it responds to environmental factors, such as sunlight and injury.Study of the integumentary system is essential to understanding how the body controls interaction between the internal and external environments.CHAPTER OBJECTIVESAfter you have studied this chapter, you should be able to:1. Define organ, and name the large organ of the integumentary system.2. List the general functions of the skin.3. Describe the structure of the various layers of the skin.4. Summarize the factors that determine skin color.5. Describe the accessory organs associated with the skin.6. Explain the functions of each accessory organ.7. Explain how the skin functions in regulating body temperature.8. Describe wound healing.9.Distinguish amoun the types of burns, including a description of healing with each type.10. Summarize the life-span changes in the integumentary system.FOCUS QUESTIONYou have spent the day on the beach in 90heat. You return to your air-conditioned home and notice that you have several insect bites that you have scratched open. How does the skin help you to adjust to the changes in temperature and prevent a systemic infection?STUDY ACTIVITIESDefine the following word parts.alb-( white )cut-( skin )derm-( skin )))hol-( entire, whole )kerat-( horn ) ) ) seb-( grease )We are now ready to move to the next higher level of organization. We’ve looked at atoms, molecules, and the macromolecules of life. The interactions of the different types of biomolecules make a living cell possible. Molecular interactions vary within cells as a result of the control of DNA in the chromosomes, making the cells differentiate. Groups of cells which have differentiated in the same way form tissues, and in the last chapter, we looked at some of the many kinds of tissues that are found in our body. We are now ready to look at the way the different tissue types work together to form organs that are part of organ systems.)).Terms to define:))))The Epiderrmis). However, warts, which appear somewhat similar, are caused by one of many types of viruses common in our environment.)Why is this process so important?). Note the differences in the images on page 175. The Dermis). It contains primarily collagen and elastin fibers, and may range from 0.5 to 3 mm in thickness. The following diagram shows many of the accessory structures that are found in the skin. Use these terms to label the structures of this diagram. adipose tissue, arrector pili muscle, basement membrane, collagen fibers , dermal papilla, dermis layer, eccrine sweat gland, eccrine sweat gland duct , epidermis, hair follicle, hair root, Miessner’s corpuscle, motor nerve fiber, pacinian corpuscle , peripheral nerve , sebaceous gland, sensory nerve endings, sensory nerve fiber, subcutaneous layer, sweat gland poreIntegument and Accessory Structures1611162712173813184914195101520Do you know these structures? Please use the terms to match the definitions in the boxes below.albinism, apocrine gland, arrector pili, basement membrane, ceruminous gland, dermal papillae, dermis, eccrine gland, epidermis, follicle, hair shaft, keratin, melanin, melanocyte, melanoma, Miessner’s Corpuscle, nail bed, nail plate, Pacinian Corpuscle, sebaceous gland, stratum basale, stratum corneum, subcutaneous layera form of hypo-pigmentary congenital disorder which results from inheritance of recessive alleles. Affected individuals lack melanin pigment in the eyes, skin and hair.A structure that supports overlying epithelial or endothelial cells. It consists of an electron-dense layer called the lamina densa, about 30–70 nanometers in thickness, and an underlying network of reticular collagen fibrils which average 30 nanometers in diameter and 0.1–2 micrometers in thickness.a type of mechanoreceptor. They are a type of nerve endings in the skin that are responsible for sensitivity to light touch. They are rapidly adaptive receptors.an outgrowth of protein, found only on mammals which projects from the epidermis, growing from hair follicles deep in the dermis.are extensions of the dermis into the epidermis. They sometimes can be perceived at the surface of the skin as friction ridges or fingerprints.base layer or stratum germinativum. mitotic layer of cuboidal cells resting on basement membrane of epidermiscells (5-25%) located in the bottom layer (the stratum basale) of the skin's epidermis and in the middle layer of the eye that produce melaninexocrine glands that develop during the early- to mid-puberty within the age range of 13 to 15. Cells bud their secretions off through the plasma membrane producing membrane bound vesicles in the lumen.fibrous structural protein; tough and insoluble, it forms the hard but nonmineralized structures found in reptiles, birds, amphibians and mammals.glands are coiled tubular glands derived from the outer layer of skin but extending into the inner layer used for body temperature regulation.glands are specialized sudoriferous glands (sweat glands) located in the external auditory canal. They produce earwax to lubricate and clean the auditory canal.glands are usually be found in hair-covered areas, where they are connected to hair follicles. The glands deposit san oily secretion on the hairs, and bring it to the skin surface along the hair shaft.layer of skin beneath the epidermis that consists of dense irregular fibrous connective tissue; it contains many nerve endings that provide the sense of touch and heat. It contains the hair follicles, sweat glands, sebaceous glands, apocrine glands, and blood vessels.Exposure to ultraviolet radiation (UVA and UVB) is one of the major contributors to the development of melanoma.one of the four major types of mechanoreceptor. They are nerve endings in the skin, responsible for sensitivity to deep pressure touch and high frequency vibration.part of the skin that grows hair by packing old cells together; extension of epidermis deep into dermispigment found in skin, hair, the pigmented tissue underlying the iris; skin color is determined by number of pigment-producing cells which are actively expressing the gene for production of the pigmentthe adherent connective tissue that underlies the nail, often colloquially referred to as the "quick".the hard and translucent portion of the fingernail, which is composed of keratinthe layer of tissue directly underlying the dermis. It is mainly composed of adipose tissue. Its physiological function includes insulation and storage of nutrients.tiny muscle fibers attached to each hair follicle, which contract to make the hairs stand on end, causing goose bumpsthe outermost layer of the epidermis (the outermost layer of the skin). It is composed mainly of dead cells that lack nuclei. As these dead cells slough off, they are continuously replaced by new cells from the baselayer.upon + skin; tissue layer found on exterior surface of organism)There are four ways which we use to get rid of excess energy. Please describe how we utilize these processes in maintaining homeostasis. ))))))Healing of wounds and burns), and the fibroblasts move away, leaving the scar tissue behind.).) which may differentiate into the necessary cell type to repair the area (see stem cells, pp 105-106 for review).) membrane which surrounded a human fetus before birth.))What are five things you have to look forward to as your integument matures?) ) ) )