Figure 5-1 The Components of the Integumentary System. Cutaneous Membrane Accessory Structures Hair shaft Epidermis Pore of sweat gland duct Papillary layer Tactile (Meissner’s) corpuscle Dermis Reticular layer Sebaceous gland Arrector pili muscle Sweat gland duct Hair follicle Lamellated (pacinian) corpuscle Hypodermis Nerve fibers Sweat gland Artery Cutaneous plexus Vein Fat p. 151

Figure 5-2 The Cutaneous Membrane and Accessory Structures. Integumentary System FUNCTIONS Physical protection from environmental hazards Storage of lipids Coordination of immune response to pathogens and cancers in skin Sensory information Synthesis of vitamin D3 Excretion Thermoregulation Cutaneous Membrane Accessory Structures Epidermis Dermis Hair Follicles Exocrine Glands Nails Protects the dermis, prevents water loss and the entry of pathogens, and synthesizes vitamin D3. Sensory receptors detect touch, pressure, pain, and temperature Papillary Layer Reticular Layer Hairs protect skull and provide delicate touch sensations on general body surface Assist in temperature regulation and waste excretion Protect and support tips of fingers and toes Nourishes and supports epidermis Has sensory receptors that detect touch, pressure, pain, vibration, and temperature. Blood vessels assist in thermoregulation p. 152

© 2015 Pearson Education, Inc. Epidermis Epidermal ridge Dermal papilla Dermis The structural relationship and interface between the epidermis and underlying dermis. The proportions of the various layers differ with the location sampled. p. 154 © 2015 Pearson Education, Inc. 3

Figure 5-2b The Basic Organization of the Epidermis Stratum corneum Basement membrane Dermis Thin skin LM  154 A micrograph of thin skin, which covers most of the exposed body surface. p. 154 © 2015 Pearson Education, Inc. 4

Figure 5-3 The Epidermis (Part 2 of 3). Characteristics Surface Stratum corneum Multiple layers of flattened, dead, interlocking keratinocytes Water resistant but not waterproof Permits slow water loss by insensible perspiration Stratum corneum Stratum lucidum Appears as a glassy layer in thick skin only Keratinocytes produce keratohyalin and keratin Keratin fibers develop as cells become thinner and flatter Gradually the plasma membranes thicken, the organelles disintegrate, and the cells die Stratum granulosum Stratum lucidum Stratum spinosum Keratinocytes are bound together by desmosomes Stratum basale Deepest, basal layer Attachment to basement membrane Contains basal cells (stem cells), melanocytes, and tactile cells (Merkel cells) Dermal papilla Basement membrane Epidermal ridge Dermis Thick skin LM × 200 p. 154 © 2015 Pearson Education, Inc.

Copyright © 2009 Pearson Education, Inc Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Figure 5-3 The Structure of the Epidermis Surface Stratum corneum Stratum lucidum Stratum granulosum Stratum spinosum Stratum basale Basement membrane Papillary layer of dermis Dermis Thick skin LM  210 © 2012 Pearson Education, Inc. 7

Figure 5-4 The Epidermal Ridges of Thick Skin Pores of sweat gland ducts Epidermal ridge p. 154 Thick skin SEM  25 © 2015 Pearson Education, Inc. 8

© 2015 Pearson Education, Inc. Figure 5-5 Melanocytes Melanocytes in stratum basale Melanin pigment Basement membrane Melanocytes LM  600 p. 156 © 2015 Pearson Education, Inc. 9

© 2015 Pearson Education, Inc. Figure 5-5 Melanocytes Melanosome Keratinocyte Melanin pigment Melanocyte Basement membrane p. 156 © 2015 Pearson Education, Inc. 10

Figure 5-1 The Components of the Integumentary System Accessory Structures Cutaneous Membrane Hair shaft Epidermis Pore of sweat gland duct Papillary layer Dermis Tactile corpuscle Reticular layer Sebaceous gland Arrector pili muscle Sweat gland duct Hair follicle Lamellated corpuscle Hypodermis Nerve fibers Sweat gland Artery Cutaneous plexus Vein Fat p. 151 © 2015 Pearson Education, Inc. 11

Figure 5-10 Dermal Circulation. Capillary loop of subpapillary plexus Dermal papillae Epidermal ridges Hair Papillary layer Reticular layer Subpapillary plexus Cutaneous plexus Lymphatic vessel p. 162 © 2015 Pearson Education, Inc.

The Epidermal Ridges of Thick Skin Pores of sweat gland ducts Epidermal ridge p. 154 Thick skin SEM  25 © 2015 Pearson Education, Inc. 13

Figure 5-9 Cleavage Lines of the Skin p. 161 ANTERIOR POSTERIOR © 2015 Pearson Education, Inc. 14

Figure 5-12a Hair Follicles and Hairs. Sebaceous gland Arrector pili muscle Connective tissue sheath Root hair plexus a Hair follicles, showing the associated accessory structures p. 164 © 2015 Pearson Education, Inc.

Figure 5-12b Hair Follicles and Hairs Hair Structure The medulla, or core, of the hair contains a flexible soft keratin. The cortex contains thick layers of hard keratin, which give the hair its stiff- ness. The cuticle, although thin, is very tough, and it contains hard keratin. Follicle Structure The internal root sheath surrounds the hair root and the deeper portion of the shaft. The cells of this sheath disintegrate quickly, and this layer does not extend the entire length of the hair follicle. The external root sheath extends from the skin surface to the hair matrix. The glassy membrane is a thickened, clear layer wrapped in the dense connective tissue sheath of the follicle as a whole. Cross section through a hair follicle and a hair, near the junction between the hair root and hair shaft. Connective tissue sheath p. 164 © 2015 Pearson Education, Inc. 16

Figure 5-12c Hair Follicles and Hairs. Hair shaft External root sheath Connective tissue sheath of hair follicle Internal root sheath Glassy membrane Cuticle of hair Cortex of hair Medulla of hair Matrix Hair papilla Subcutaneous adipose tissue Hair follicle LM × 60 c Histological section along the longitudinal axis of hair follicles p. 164 © 2015 Pearson Education, Inc.

Figure 5-12d Hair Follicles and Hairs. Connective tissue sheath of hair follicle Glassy membrane External root sheath Internal root sheath Cuticle of hair Cortex of hair Medulla of hair Matrix Hair papilla Hair bulb Subcutaneous adipose tissue d Diagrammatic view of the base of a hair follicle p. 164 © 2015 Pearson Education, Inc.

Figure 5-13 The Structure of Sebaceous Glands and Sebaceous Follicles Lumen (hair removed) Sebaceous follicle Sebaceous gland Wall of hair follicle Basement membrane Epidermis Discharge of sebum Lumen Dermis Breakdown of cell membranes Mitosis and growth Subcutaneous layer Basal cells Sebaceous gland LM  150 p. 166 © 2015 Pearson Education, Inc. 19

© 2015 Pearson Education, Inc. Figure 5-14a Sweat Glands Myoepithelial cell Sweat pore Connective tissue of dermis Duct Apocrine gland cells Duct of apocrine sweat gland Lumen A section through a merocrine sweat gland Sectional plane through apocrine sweat gland Apocrine sweat gland LM  459 Apocrine sweat glands secrete a thick, odorous fluid into hair follicles. p. 167 © 2015 Pearson Education, Inc. 20

© 2015 Pearson Education, Inc. Figure 5-14b Sweat Glands Sweat pore Duct Myoepithelial cells Merocrine gland cells Duct of apocrine sweat gland Lumen A section through a merocrine sweat gland Merocrine sweat gland LM  243 Sectional plane through apocrine sweat gland Merocrine sweat glands discharge a watery fluid onto the surface of the skin. p. 167 © 2015 Pearson Education, Inc. 21

Figure 5-15 The Structure of a Nail Direction of growth Lateral nail groove Nail body Free edge Lateral nail fold Nail bed Nail body Lunula Phalanx (bone of fingertip) Proximal nail fold A cross-sectional view Eponychium A superficial view Eponychium Nail body Proximal nail fold Lunula Nail root p. 169 Epidermis Dermis Phalanx Hyponychium A longitudinal section © 2015 Pearson Education, Inc. 22

Figure 5-13c The Structure of a Nail Eponychium Lunula Nail body Proximal nail fold Nail root Epidermis Dermis Phalanx Hyponychium A longitudinal section p. 169 © 2015 Pearson Education, Inc. 23

Figure 5-16 Repair of Injury to the Integument (Part 1 of 4). Inflammatory Phase Bleeding occurs at the site of injury immediately after the injury, and mast cells in the region trigger an inflammatory response. Epidermis Dermis Mast cells p. 170 © 2015 Pearson Education, Inc.

Figure 5-16 Repair of Injury to the Integument (Part 2 of 4). Migratory Phase After several hours, a scab has formed and cells of the stratum basale are migrating along the edges of the wound. Phagocytic cells are removing debris, and more of these cells are arriving with the enhanced circulation in the area. Clotting around the edges of the affected area partially isolates the region. Migrating epithelial cells Macrophages and fibroblasts Granulation tissue p. 170 © 2015 Pearson Education, Inc.

Figure 5-16 Repair of Injury to the Integument (Part 3 of 4). Proliferation Phase About a week after the injury, the scab has been undermined by epidermal cells migrating over the collagen fiber meshwork produced by fibroblast proliferation and activity. Phagocytic activity around the site has almost ended, and the fibrin clot is dissolving. Fibroblasts p. 170 © 2015 Pearson Education, Inc.

Figure 5-16 Repair of Injury to the Integument (Part 4 of 4). Scarring Phase After several weeks, the scab has been shed, and the epidermis is complete. A shallow depression marks the injury site, but fibroblasts in the dermis continue to create scar tissue that will gradually elevate the overlying epidermis. 4 Scar tissue p. 170 © 2015 Pearson Education, Inc.

© 2015 Pearson Education, Inc. A Quick Method of Estimating the Percentage of Surface Area Affected by Burns Head 9% Upper limb 9% each Trunk 36% (front and back) Head 15% Trunk 32% (front and back) Genitalia 1% Upper limb 9% each Lower limb 18% each Genitalia 1% Lower limb 17% each p. 171 ADULT CHILD (5-year-old) © 2015 Pearson Education, Inc. 28