Integument Composition and Functions

7% to 8%

1.5 mm to 4 mm or more

Epidermis

<p>Areolar and dense irregular connective tissue</p> Signup and view all the answers

<p>To alter hair position</p> Signup and view all the answers

<p>Subcutaneous layer or hypodermis</p> Signup and view all the answers

<p>Nervous tissue</p> Signup and view all the answers

<p>Between about 1.5 and 2.0 square meters</p> Signup and view all the answers

<p>Epidermis</p> Signup and view all the answers

<p>1.5-4 mm</p> Signup and view all the answers

<p>Stratum corneum</p> Signup and view all the answers

<p>Keratinocytes</p> Signup and view all the answers

<p>To shield nuclear DNA from UV radiation</p> Signup and view all the answers

<p>Tactile cells (Merkel cells)</p> Signup and view all the answers

<p>Stratum basale</p> Signup and view all the answers

<p>Melanosomes</p> Signup and view all the answers

<p>Keratin</p> Signup and view all the answers

<p>Tanning</p> Signup and view all the answers

<p>A nondividing, highly specialized keratinocyte</p> Signup and view all the answers

<p>To provide structural support between cells of the epidermis</p> Signup and view all the answers

<p>Because the cytoskeleton and desmosomes remain intact after cytoplasm shrinkage during microscopic preparation</p> Signup and view all the answers

<p>To help fight infection by initiating an immune response</p> Signup and view all the answers

<p>Keratinization</p> Signup and view all the answers

<p>To help protect the skin from ultraviolet light</p> Signup and view all the answers

<p>About 20 to 30 layers of dead, scaly, interlocking, keratinized cells</p> Signup and view all the answers

<p>Keratin protein enclosed in a thickened plasma membrane</p> Signup and view all the answers

<p>About 2 weeks</p> Signup and view all the answers

<p>Their keratin protein remains, forming the outermost layer of the epidermis</p> Signup and view all the answers

<p>Hemoglobin is an oxygen-binding protein that exhibits a bright red color upon binding oxygen, giving blood vessels in the dermis a reddish tint.</p> Signup and view all the answers

<p>The two types of melanin are eumelanin, which produces shades of brown and black, and pheomelanin, which produces lighter shades of tan, yellow, and red.</p> Signup and view all the answers

<p>Melanocyte activity affects the color of the entire epidermis because melanin is transferred from melanocytes to keratinocytes in the stratum basale, which are then displaced towards the stratum corneum.</p> Signup and view all the answers

<p>Carotene is a yellow-orange pigment acquired from yellow-orange vegetables, typically found in keratinocytes of the stratum corneum and in subcutaneous fat.</p> Signup and view all the answers

<p>Darker-skinned individuals have melanocytes that produce more and darker melanin, which is packaged into cells in more superficial epidermal layers, such as the stratum granulosum.</p> Signup and view all the answers

<p>Exposure to UV light stimulates melanocytes to produce more melanin, temporarily altering skin color. Melanocytes play a crucial role in this process by producing melanin in response to UV light.</p> Signup and view all the answers

<p>The three forms of ultraviolet radiation are UVA, UVB, and UVC. UVA and UVB rays can cause skin cancer and affect skin color, while UVC rays are absorbed by the upper atmosphere and do not reach the earth's surface.</p> Signup and view all the answers

<p>Vitamin A plays an important role in vision and reduces free radicals in the body. It is converted from carotene in the liver.</p> Signup and view all the answers

<p>UVA rays are often referred to as tanning rays, while UVB rays are referred to as burning rays. However, UVA rays can also cause burning and suppress the immune system, debunking the myth that they are safe.</p> Signup and view all the answers

<p>Melanin gives skin its color, and the amount and type of melanin present in the epidermis determine an individual's skin color. Heredity and exposure to UV light influence melanin production and skin color.</p> Signup and view all the answers

<p>To ensure complete protection of the skin from UVA and UVB rays.</p> Signup and view all the answers

<p>By interacting with amino acids in the epidermal cells to produce a darkened, brownish color.</p> Signup and view all the answers

<p>Melanocytes are unable to produce melanin, leading to white hair, pale skin, and pink irises.</p> Signup and view all the answers

<p>To detect possible malignancy, as nevi can develop into malignant melanomas due to excessive UV light exposure.</p> Signup and view all the answers

<p>Capillary hemangiomas are bright red to deep purple nodules that usually appear at birth and disappear in childhood, while cavernous hemangiomas involve larger dermal blood vessels and may last a lifetime.</p> Signup and view all the answers

<p>To increase friction on contact, allowing firm grasping and preventing slipping, as well as providing flexibility to the skin.</p> Signup and view all the answers

<p>Dermatoglyphics</p> Signup and view all the answers

<p>Because sunless tanners do not offer protection against UV rays, and protective melanin has not been produced.</p> Signup and view all the answers

<p>Both sun exposure and heredity.</p> Signup and view all the answers

<p>It indicates the level of protection against UVB rays, with higher numbers providing longer protection from sunburn.</p> Signup and view all the answers

<p>The stratum corneum provides a barrier against many microorganisms and helps prevent their growth on the epidermis. The dead, keratinized cells remain in this layer for about 2 weeks before they are shed.</p> Signup and view all the answers

<p>The main difference is the number of layers and thickness of the stratified squamous epithelium. Thick skin has all five epidermal strata and is typically found on the palms of the hands and soles of the feet, while thin skin has only four epidermal strata and covers most body surfaces.</p> Signup and view all the answers

<p>Sweat, which contains demicidin, an antimicrobial peptide, is an example of an exocrine gland secretion that helps prevent the growth of microorganisms on the epidermis.</p> Signup and view all the answers

<p>Thick skin lacks hair follicles and sebaceous glands likely because they would interfere with the function of skin in areas that require durability and resistance to wear and tear, such as the palms and soles.</p> Signup and view all the answers

<p>Normal skin color results from a combination of the colors of hemoglobin, melanin, and carotene.</p> Signup and view all the answers

<p>To identify the epidermal strata, determine the layer's proximity to the free surface, examine the shape of keratinocytes, check for the presence of nuclei, count the layers of keratinocytes, and look for visible granules in the cytoplasm.</p> Signup and view all the answers

<p>The epidermis of thick skin is between 0.4 mm and 0.6 mm thick, while the epidermis of thin skin is between 0.075 mm and 0.150 mm thick.</p> Signup and view all the answers

<p>Thin skin contains hair follicles, sebaceous glands, and sweat glands, whereas thick skin lacks hair follicles and sebaceous glands, but has sweat glands.</p> Signup and view all the answers

<p>Individual keratinocytes are present in the integument for about 1 month following their formation, and they remain in the stratum corneum for about 2 weeks before being shed.</p> Signup and view all the answers

<p>The stratum lucidum is present in thick skin, but absent in thin skin. It is a layer of dead, anucleate keratinocytes that provides additional barrier function to the epidermis.</p> Signup and view all the answers

<p>The interlocking projections represent the epidermal ridges and dermal papillae, which increase the surface area of interaction between the two layers.</p> Signup and view all the answers

<p>Lines of cleavage are clinically significant because they indicate the predominant direction of collagen fiber bundles, which can affect wound healing and scarring.</p> Signup and view all the answers

<p>Collagen fibers impart tensile strength, while elastic fibers allow for stretch and recoil during normal movement activities.</p> Signup and view all the answers

<p>Friction ridge patterns are a unique identifier because no two individuals, including identical twins, share the same set of fingerprints. They form fingerprints, palm prints, sole prints, and toe prints due to the formation of friction ridges.</p> Signup and view all the answers

<p>Stretch marks are caused by excessive stretching of the skin, which can tear collagen fibers and lead to the formation of striae. This can result in decreased skin elasticity and thickness.</p> Signup and view all the answers

<p>The thorn would penetrate the stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, and stratum basale.</p> Signup and view all the answers

<p>Tattoos become permanent because the injected dye becomes surrounded by scar tissue in the dermis, which cannot be ingested by dendritic cells. This makes it difficult to remove tattoos without causing scarring.</p> Signup and view all the answers

<p>The papillary layer is thin and contains loose connective tissue, while the reticular layer is thicker and contains dense irregular connective tissue with collagen and elastic fibers.</p> Signup and view all the answers

<p>Keratinization is the process of producing keratin, a protein that provides strength and rigidity to the epidermis. It occurs in the stratum spinosum and stratum granulosum. It is important because it helps to protect the body from external damage.</p> Signup and view all the answers

<p>Hemoglobin contributes to skin color by giving it a red or pinkish hue, especially in areas where blood vessels are close to the surface.</p> Signup and view all the answers

<p>The subcutaneous layer provides cushioning and insulation, and consists of both areolar and adipose connective tissue.</p> Signup and view all the answers

<p>through the action of UV light on 7-dehydrocholesterol in the skin</p> Signup and view all the answers

<p>The two major regions of the dermis are the papillary layer and the reticular layer. The papillary layer is superficial, composed of areolar connective tissue, and contains dermal papillae and capillaries. The reticular layer is deeper, composed of dense irregular connective tissue, and contains collagen fibers and structures like hair follicles and sebaceous glands.</p> Signup and view all the answers

<p>Dermal papillae are projections of the dermis that increase the surface area of interaction with the epidermis, allowing for better exchange of nutrients and waste.</p> Signup and view all the answers

<p>Dermal papillae contain capillaries that supply nutrients to the epidermis and sensory nerve endings that serve as tactile receptors. They interdigitate with epidermal ridges, increasing the area of contact between the two layers and interlocking them.</p> Signup and view all the answers

<p>Surgeons plan incisions to be parallel to lines of cleavage to minimize scarring and promote rapid healing.</p> Signup and view all the answers

<p>The papillary layer is composed of areolar connective tissue, while the reticular layer is composed of dense irregular connective tissue.</p> Signup and view all the answers

<p>Cleavage lines are not mentioned explicitly in the provided text. However, in general, cleavage lines are important in the dermis because they influence the direction of wound healing and the formation of scars.</p> Signup and view all the answers

<p>Dendritic cells in the dermis serve an immune function. They are similar to epidermal dendritic cells in that they also serve an immune function, but they are located in the dermis rather than the epidermis.</p> Signup and view all the answers

<p>The dermis contains structures such as blood vessels, sweat glands, sebaceous glands, hair follicles, nail roots, sensory nerve endings, and smooth muscle tissue associated with hair follicles. These structures are significant because they provide various functions, including thermoregulation, sensation, and hair growth.</p> Signup and view all the answers

<p>to detect, distinguish, and interpret the many stimuli of our external environment</p> Signup and view all the answers

<p>Exposure to UV light causes the dermis to become less flexible and thinner, leading to sagging or wrinkled skin.</p> Signup and view all the answers

<p>it provides a well-vascularized connective tissue layer that supports the skin's functions, such as secretion, absorption, and temperature regulation</p> Signup and view all the answers

<p>through sweating, vasodilation, and radiation</p> Signup and view all the answers

<p>through the combination of the epidermis and dermis, which together provide a protective barrier, regulate water loss and gain, and facilitate various other functions</p> Signup and view all the answers

<p>it helps to protect the body against infection and disease by recognizing and responding to pathogens</p> Signup and view all the answers

<p>They are extensively interwoven to stabilize the position of the skin and bind it to the underlying structures.</p> Signup and view all the answers

<p>Because of its extensive vascular network, which promotes rapid absorption of the drugs.</p> Signup and view all the answers

<p>Testosterone leads to accumulation primarily at the neck, upper arms, abdomen, lower back, and buttocks, while estrogen and progesterone lead to thicker overall fat and accumulation in the mammary regions, buttocks, hips, and thighs.</p> Signup and view all the answers

<p>It forms dermal papillae and houses capillaries and tactile receptors.</p> Signup and view all the answers

<p>It helps retain warmth or cool the body by means of sweating and vasodilation.</p> Signup and view all the answers

<p>Dendritic cells in the integument initiate an immune response.</p> Signup and view all the answers

<p>It helps prevent fluid loss, thereby assisting the cardiovascular system in maintaining blood volume.</p> Signup and view all the answers

<p>It synthesizes vitamin D, which is required for calcium homeostasis.</p> Signup and view all the answers

<p>They help filter inspired air, assisting the respiratory system.</p> Signup and view all the answers

<p>It excretes nitrogenous waste products, along with the urinary system.</p> Signup and view all the answers

<p>The skin acts as a physical barrier that protects the entire body from the external environment, offering protection against harmful chemicals, toxins, microbes, and excessive heat or cold.</p> Signup and view all the answers

<p>The epidermis is water resistant, but not entirely waterproof, and prevents water loss through transpiration and sweat. It also prevents water gain by being resistant to water absorption.</p> Signup and view all the answers

<p>Keratinocytes in the epidermis convert a steroid molecule (7-dehydrocholesterol) to vitamin D3 in response to UV light exposure.</p> Signup and view all the answers

<p>Children during the Industrial Revolution developed rickets due to inadequate vitamin D, likely resulting from limited sunlight exposure and inadequate dietary intake.</p> Signup and view all the answers

<p>The skin regulates electrolyte levels in the body through the excretion of sweat, which contains water, salts, and urea.</p> Signup and view all the answers

<p>Melanin in the epidermis protects deeper tissues from solar radiation, especially UV rays, and provides a tanned look when exposed to sunlight.</p> Signup and view all the answers

<p>The skin's secretory function contributes to thermoregulation through the excretion of sweat, which acts to release excess heat from the body.</p> Signup and view all the answers

<p>Topical corticosteroids are converted and used by keratinocytes to stop inflammation and itching.</p> Signup and view all the answers

<p>The skin's water-resistant properties prevent excessive water absorption, which would lead to edema and tissue damage.</p> Signup and view all the answers

<p>Vitamin D synthesis in the skin is initiated in response to UV light exposure, which triggers the conversion of 7-dehydrocholesterol to vitamin D3.</p> Signup and view all the answers

<p>to lubricate the epidermis and hair, and help make the integument water resistant</p> Signup and view all the answers

<p>by releasing a continual, slow absorption of the drug into the blood over a relatively long period of time</p> Signup and view all the answers

<p>it shunts blood away from the periphery of the body and toward deeper structures, conserving heat</p> Signup and view all the answers

<p>to initiate an immune response against pathogens that have penetrated the skin</p> Signup and view all the answers

<p>it shunts blood to the periphery of the body and away from deeper structures, releasing excess heat</p> Signup and view all the answers

<p>because the epidermis is composed of cells, allowing for the unregulated passage of small, nonpolar molecules through the plasma membrane</p> Signup and view all the answers

<p>to cool the body through evaporation of sweat</p> Signup and view all the answers

<p>by regulating blood flow to and from the periphery of the body, allowing for heat conservation or release</p> Signup and view all the answers

<p>they regulate sweat glands, sebaceous glands, and dermal blood vessels to maintain homeostasis</p> Signup and view all the answers

<p>through the epidermis and into the blood vessels within the dermis, allowing for slow and continuous absorption</p> Signup and view all the answers