Copyright © 2019, Elsevier Inc. All Rights Reserved. 1Chapter 47: Structure, Function, and Disorders of the IntegumentMcCance/Huether: Pathophysiology: The Biologic Basis of Disease in Adults and Children, 8th EditionMULTIPLE CHOICE 1. Which component of the epidermis initiates immune responses and provides a defense against environmental antigens?a. Langerhans cellsb. Merkel cellsc. Keratinocytesd. MelanocytesANS: ALangerhans cells (a type of dendritic cell) and dermal dendritic cells initiate an immune response by presenting processed antigen to T cells, thus providing a defense against environmental antigens. This function is not carried out by Merkel cells, keratinocytes, or melanocytes.PTS: 1 DIF: Cognitive Level: Remembering 2. Which cells of the dermis release histamine and play a role in the hypersensitivity reactions of the skin?a. Histiocytesb. Fibroblastsc. Mast cellsd. MacrophagesANS: COnly mast cells release histamine and play a role in hypersensitivity reactions in the skin. Histiocytes are macrophages that reside in loose connective tissue and phagocytize pigments and the debris of inflammation. Fibroblast cells secrete collagen and connective tissue matrix. Macrophages are phagocytic.PTS: 1 DIF: Cognitive Level: Remembering 3. Which cells of the dermis secrete connective tissue matrix?a. Macrophagesb. Mast cellsc. Fibroblastsd. HistiocytesANS: COnly fibroblasts secrete the connective tissue matrix and collagen. Macrophages are phagocytic cells. Mast cells release histamine and play a role in hypersensitivity reactions in the skin. Histiocytes are a type of macrophage found in loose connective tissue.PTS: 1 DIF: Cognitive Level: Remembering 4. Which gland releases secretions that are important in thermoregulation and cooling of the body through evaporation?a. Sebaceousb. Apocrinec. Eccrined. ExocrineANS: CThe eccrine sweat glands are distributed over the body, with the greatest numbers in the palms of the hands, soles of the feet, and forehead. These secretions are important in thermoregulation and cooling of the body through evaporation. Sebaceous glands secrete sebum which is a lipid substance that protects from drying. Apocrine glands are found in the axillae, scalp, face, abdomen, and genital area and have very limited proven function. Exocrine glands secrete substances onto the epithelial surface; an example is a sweat gland.PTS: 1 DIF: Cognitive Level: Remembering 5. Which receptors of the sympathetic nervous system regulate heat loss through the skin?a. Cholinergicb.β-Adrenergicc. α-Adrenergicd. AnticholinergicANS: CHeat loss can be regulated by varying blood flow through the skin by opening and closing the arteriovenous anastomoses in conjunction with evaporative heat loss of sweat. The sympathetic nervous system regulates vasoconstriction and vasodilation through α-adrenergic receptors only.PTS: 1 DIF: Cognitive Level: RememberingCopyright © 2019, Elsevier Inc. All Rights Reserved. 2 6. The healthcare professional is assessing four patients for pressure ulcer formation. What is the first change in the skin that the professional would note if a patient were developing a pressure ulcer?a. Blanchable erythema of intact skinb. Nonblanchable erythema of intact skinc. Blister at the site of pressured. Reddish-purple discolorationANS: BNonblanchable erythema of intact skin, usually over bony prominences, characterizes stage 1 pressure ulcers. A blister would indicate a deep tissue pressure injury as would a reddish-purple discoloration. Blanchable erythema of intact skin would not indicate any pressure damage.PTS: 1 DIF: Cognitive Level: Remembering 7. Which type of dressings should the healthcare professional apply to pressure ulcers?a. Flat and dryb. Flat, moisture-retainingc. Bulky and dryd. Bulky, moisture-retainingANS: BSuperficial pressure ulcers should be covered with flat, nonbulky dressings that cannot wrinkle or cause increased pressure or friction. The dressing should be moisture-retaining such as Hydrogel.PTS: 1 DIF: Cognitive Level: Remembering 8. What term is used to identify skin lesions that are elevated, rounded, and firm with irregular clawlike margins that extend beyond the original site of injury?a. Psoriasisb. Dermatitisc. Acned. KeloidANS: DKeloids typically send out clawlike projections from the margins.PTS: 1 DIF: Cognitive Level: Remembering 9. Keloids are caused by excessive amounts of which substance in the corneum during connective tissue repair?a. Elastinb. Collagenc. Stromad. Reticular fibersANS: BAbnormal wound healing with excessive fibroblast activity and collagen formation during dermal connective tissue repair cause keloids. The other substances are not associated with keloid formation.PTS: 1 DIF: Cognitive Level: Remembering 10. In allergic contact dermatitis, which cells possess the antigens and present them to T cells?a. Langerhans cellsb. Merkel cellsc. Keratinocytesd. MacrophagesANS: AIn allergic contact dermatitis, Langerhans cells process the antigen and carry it to T cells that then become sensitized to the antigen-releasing cytokines and chemokines, leading to leukocyte infiltration and inflammation. Merkel cells are associated with touch receptors and function as slowly adapting mechanoreceptors when stimulated by deformation of the epidermis. Keratinocytes produce keratin, a scleroprotein that provides protection from mechanical stress. Keratin is the main constituent of skin, hair, and nail cells.PTS: 1 DIF: Cognitive Level: Remembering 11. In latex allergies, which immunoglobulin (Ig) is associated with an immediate reaction?a. IgAb. IgEc. IgGd. IgMANS: BLatex allergy can be either a type IV hypersensitivity to chemicals used in latex rubber processing or a type I immediate hypersensitivity, with IgE antibodies formed in response to latex rubber protein.PTS: 1 DIF: Cognitive Level: RememberingCopyright © 2019, Elsevier Inc. All Rights Reserved. 3 12. A patient in the clinic is diagnosed with dermatitis. The patient states that a previous healthcare professional diagnosed eczema. What response by the healthcare professional is best?a. “Both are general terms for a specific inflammatory response in the skin.”b. “Eczema is an older, outdated term. The preferred term is dermatitis.”c. “No, it’s not eczema. Eczema has yellowish scaly plaques.”d. “If it were eczema, it would have blisters that go away on their own.”ANS: AThe most common inflammatory disorder of
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