Co 5

Hairs Epidermis Sebaceous gland Skin Arrector pili Dermis Fig. 5.1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Hairs Epidermis Sebaceous gland Skin Arrector pili (smooth muscle) Dermis Hair follicle Nerve Vein Artery Subcutaneous tissue (hypodermis) Sweat gland Adipose tissue

An incision made across cleavage lines can gap, Fig. 5.3 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. An incision made across cleavage lines can gap, increasing the time needed for healing and resulting in increased scar tissue formation. An incision made parallel to cleavage lines results in less gapping, faster healing, and less scar tissue.

Epidermis Dermal papilla (a) Fig. 5.2-1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Epidermis Dermal papilla (a)

Hairs Epidermis Sebaceous gland Skin Arrector pili Dermis Fig. 5.1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Hairs Epidermis Sebaceous gland Skin Arrector pili (smooth muscle) Dermis Hair follicle Nerve Vein Artery Subcutaneous tissue (hypodermis) Sweat gland Adipose tissue

Melanosomes are produced by the Golgi apparatus of the melanocyte. Fig. 5.4 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1 Melanosomes are produced by the Golgi apparatus of the melanocyte. 2 Melanosomes move into the melanocyte cell processes. 3 Epithelial cells phagocytize the tips of the melanocyte cell processes. 4 The melanosomes, which were produced inside the melanocytes, have been transferred to epithelial cells and are now inside them. 3 4 Epithelial cell Melanocyte 2 Melanosomes 1 Nucleus Golgi apparatus

Fig. 5.10 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. (a) (b) (c) © Thomas B. Habif

Hairs Epidermis Sebaceous gland Skin Arrector pili Dermis Fig. 5.1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Hairs Epidermis Sebaceous gland Skin Arrector pili (smooth muscle) Dermis Hair follicle Nerve Vein Artery Subcutaneous tissue (hypodermis) Sweat gland Adipose tissue

Fig. 5.5 Hair shaft (above skin surface) Medulla Hair root (below skin Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Hair shaft (above skin surface) Medulla Hair root (below skin surface) Cortex Hair Cuticle Arrector pili (smooth muscle) Sebaceous gland Hair follicle wall Hair bulb (base of hairroot) Artery Vein Hair papilla Adipose tissue (a) Medulla Cortex Hair Cuticle Connective tissue Site of cell divisions that produce the cells of the hair Hair follicle wall Epithelial tissue Melanocyte Stratum basale Hair papilla Basement membrane (b)

Fig. 5.7 Free edge Cuticle Nail body Nail root (under the skin) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Free edge Cuticle Nail body Nail root (under the skin) Nail body Free edge Nail matrix Lunula Nail bed Bone Cuticle Epidermis Nail root

Sweat pores Duct of eccrine sweat gland Duct of Arrector pili apocrine Fig. 5.6 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Sweat pores Duct of eccrine sweat gland Duct of apocrine sweat gland Arrector pili (smooth muscle) Hair follicle Sebaceous gland Eccrine sweat gland Hair bulb Apocrine sweat gland

Fig. 5.8 1 Blood vessel dilation results in Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1 Blood vessel dilation results in increased blood flow toward the surface of the skin. Blood vessel dilates. 1 2 Heat loss across the epidermis increases. 2 Increased blood flow beneath the epidermis results in increased heat loss (gold arrows). Blood vessel constricts. 3 Blood vessel constriction results in decreased blood flow toward the surface of the skin. 3 4 Heat loss across the epidermis decreases. 4 Decreased blood flow beneath the epidermis results in decreased heat loss.

Partial- thickness Full- thickness First- degree Second- degree Third- Fig. 5.9 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Partial- thickness Full- thickness First- degree Second- degree Third- degree Epidermis Dermis Subcutaneous tissue