1. Chapter 5 Skin and the Integumentary System
Composed of several tissues
Maintains homeostasis
Protective covering
Retards water loss
Regulates body temperature
Houses sensory receptors
Contains immune system cells
Synthesizes chemicals
Excretes small amounts of waste
5-1

2. Layers of Skin
Epidermis
Dermis
Subcutaneous layer
5-2

3. Epidermis lacks blood vessels keratinized
thickest on palms and soles ( mm)
melanocytes provide melanin
stratified squamous
5-3

4. Dermis on average 1.0-2.0mm thick dermal papillae binds epidermis to
underlying tissues
irregular dense
connective tissue
nerve cell processes
blood vessels
hair follicles
glands
arrector pili
5-4

5. Subcutaneous Layer hypodermis loose connective tissue adipose tissue
insulates
major blood vessels
5-5

6. Hair Follicles epidermal cells extends into dermis hair root
hair shaft
hair papilla
melanin
arrector pili muscle
lanugo
absent on lips, palms,
soles
5-6

7. Nails protective coverings nail plate (body) nail bed lunula root
_____Free Edge
nail bed
Cuticle_________
lunula
root
5-7

8. Sweat Glands sudoriferous glands widespread in skin deep dermis or
hypodermis
eccrine glands
apocrine glands
5-8

9. Sebaceous Glands usually associated with hair follicles secrete sebum
absent on palms and soles
5-9

10. Regulation of Body Temperature
5-10

11. Problems in Temperature Regulation
Hyperthermia – abnormally high body temperature
Hypothermia – abnormally low body temperature
5-11

12. Skin Color Physiological Factors Genetic Factors
dilation of dermal blood vessels
constriction of dermal blood vessels
carotene
jaundice
Genetic Factors
varying amounts of melanin
varying size of melanin granules
albinos lack melanin
Environmental Factors
sunlight
UV light from sunlamps
5-12

13. 5-13

14. Clinical Application Acne Vulgaris most common skin disorder
sebum and epithelial cells clog glands
produces whiteheads and blackheads (comedones)
anaerobic bacteria trigger inflammation (pimple)
largely hormonally induced
androgens stimulate sebum production
treatments include antibiotics, topical creams, birth control pills
5-14