1. Fig. 6.1 Hairs Sweat pores Dermal papilla Epidermis Tactile corpuscle
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Hairs
Sweat pores
Dermal papilla
Epidermis
Tactile corpuscle
(touch receptor)
Blood capillaries
Hair follicle
Dermis
Sebaceous gland
Hair receptor
Apocrine sweat gland
Hypodermis
(subcutaneous fat)
Hair bulb
Sensory
nerve fibers
Merocrine sweat
gland
Piloerector muscle
Cutaneous blood
vessels
Lamellar (pacinian)
corpuscle (pressure receptor)
Motor nerve fibers

2. Fig. 6.3 2 Sweat pore Stratum corneum Exfoliating Stratum lucidum
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Sweat pore
Stratum corneum
Exfoliating
keratinocytes
Stratum lucidum
Stratum granulosum
Dead keratinocytes
Sweat duct
Living keratinocytes
Dendritic cell
Stratum spinosum
Tactile cell
Melanocyte
Stem cell
Stratum basale
Dermal papilla
Tactile nerve fiber
Dermis
Dermal blood vessels 2

3. Fig. 6.5 3 (b) Papillary layer of dermis (a)
Copyright © McGraw-Hill Education. Permission required for reproduction or display.
(b) Papillary layer of dermis
(a)
(c) Reticular layer of dermis
a: © McGraw­Hill Education/Dennis Strete; b: © Dr. Richard Kessel & Dr. Randy K./Visuals Unlimited/Corbis; c: © Dr. Kessel & Dr. Kardon/Tissues and Organs/Visuals Unlimited, Inc 3

4. Table 6.1 4

5. Fig. 6.6 5 Stratum corneum Epidermis Melanized cells of stratum basale
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Stratum corneum
Epidermis
Melanized cells
of stratum basale
Dermis
(a) Dark skin
(b) Light skin
Top left: © Tom & Dee Ann McCarthy/Corbis; Top right: © Creatas/PunchStock RF; a-b: © McGraw­Hill Education/Dennis Strete 5

6. Fig. 6.7 6 Connective tissue root sheath Hair shaft Epithelial root
Copyright © McGraw-Hill Education. Permission required for reproduction or display.
Connective
tissue
root sheath
Hair shaft
Epithelial root
sheath
Hair medulla
Sebaceous
gland
Piloerector
muscle
Hair cortex
Hair receptor
Bulge
Hair root
Hair matrix
Hair bulb
Apocrine
sweat gland
Dermal
papilla
Blood
Capillaries
in dermal
papilla
(a)
(b)
0.5 µm
b: ©CBS/Phototake 6

7. Fig. 6.9 7 Telogen Old club hair Epidermis Sebaceous gland Club hair
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Old club hair
Epidermis
Sebaceous
gland
Club hair
(detached
from matrix)
Piloerector
New hair
Club
Bulge
Hair matrix
Hair bulb
Degeneration
of lower follicle
Dermis
Dermal papilla 1
Anagen (early)
Anagen (mature) 2
Catagen 3
Telogen
(Growing phase, 6–8 years)
Stem cells multiply and follicle grows deeper into dermis; hair matrix
cells multiply and keratinize, causing hair to grow upward; old club hair
may persist temporarily alongside newly growing hair.
(Degenerative phase, 2–3 weeks)
Hair growth ceases; hair bulb
keratinizes and forms club hair;
lower follicle degenerates.
(Resting phase, 1–3 months)
Dermal papilla has ascended
to level of bulge; club hair falls
out, usually in telogen or
next anagen. 7

8. Fig. 6.10 8 Free edge Nail body Nail groove Nail fold Lunule
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Free edge
Nail body
Nail groove
Nail fold
Lunule
Eponychium
(cuticle)
Eponychium
Nail plate
Nail
fold
Free
edge
Nail
body
Nail
root
Nail bed
Nail matrix 8

9. a–c: © McGraw-Hill Education/Dennis Strete
Fig. 6.11
Copyright © McGraw-Hill Education. Permission required for reproduction or display.
Lumen
Secretory
cells
Myoepithelial
cells
Lumen
Secretory cells
(a) Apocrine gland
(b) Merocrine gland
Gland
Hair follicle
(c) Sebaceous gland
a–c: © McGraw-Hill Education/Dennis Strete 9

10. Table 6.2 10

11. Page 198
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All SYSTEMS
Skin covers the body and provides a barrier to pathogens and to excessive water loss; epidermal keratinocytes initiate synthesis of calcitriol, with effects on multiple other organ systems as noted.
SKELETAL SYSTEM
Bone growth and maintenance
depend on calcium, which is
absorbed from the diet under
the influence of calcitriol.
LYMPHATIC/
IMMUNE SYSTEM
Dendritic cells of the skin alert the immune system when pathogens breach the epidermal barrier.
MUSCULAR SYSTEM
Muscle contraction depends on
calcium, which is absorbed from the diet under the influence of calcitriol.
RESPIRATORY SYSTEM
Nasal guard hairs block some airborne debris from being inhaled; calcium is required for the secretion of respiratory mucus, which therefore depends on calcitriol.
NERVOUS SYSTEM
The transmission of nerve signals across synapses depends on calcium, which is absorbed from the diet under the influence of calcitriol.
URINARY SYSTEM
Skin complements the urinary system by excreting salts and some nitrogenous waste in the sweat; calcitriol promotes reabsorption of calcium by the kidneys.
ENDOCRINE SYSTEM
Hormone secretion depends on calcium as a trigger for exocytosis and, therefore, on calcitriol; the role of epidermal keratinocytes in synthesizing calcitriol is itself an endocrine function.
DIGESTIVE SYSTEM
By their role in calcitriol synthesis, keratinocytes influence intestinal absorption of calcium; calcium is needed for the secretion of all digestive enzymes and mucus.
REPRODUCTIVE SYSTEM
Cutaneous nerve endings are important in sexual stimulation; mammary glands produce milk; apocrine sweat glands secrete pheromones that affect sexual behavior and physiology; skin stretches to accommodate abdominal growth in pregnancy.
CIRCULATORY SYSTEM
The skin is a major blood reservoir; cutaneous vasoconstriction diverts blood to other organs; skin supports blood volume by retarding fluid loss; dermal vasoconstriction and vasodilation help to regulate blood temperature. 11