1. Skin Histology Epidermal Derivatives J.F. Thompson, Ph.D.
Chapter 5
Skin Histology
Epidermal Derivatives
J.F. Thompson, Ph.D.

2. Hair Distribution Varies Over the Body Surface

3. Hair Follicles

4. Hair Anatomy Shaft Root Follicle - surrounds root
medulla - inner layer
cortex - middle layer, pigments, air spaces
cuticle - outermost layer, hard keratin
Root
similar to shaft, but within dermis
Follicle - surrounds root
Sheath - supports shaft & root
Bulb - enlarged layered structure at base where hair is generated
papilla - areolar connective tissue, blood vessels supply nutrients
matrix - germination layer of papilla (stratum basale) builds hair shaft
Sebaceous glands – release oil
Arrector Pili – smooth muscle

5. Hairs & Lice
egg
crab louse
head
louse

6. Arrector Pili (smooth muscle)

7. Sweat Glands

8. Sebaceous Glands

9. Nails tightly packed, hard, keratinized cells
nail matrix - under root of nail
site of nail growth
transforms normal skin cells into nail cells which push forward
1mm/week in fingers; slower in toes
the longer the finger the greater the growth rate

10. Nails Tightly packed cells with hard keratin
Nail matrix - under root of nail
site of nail growth
transforms normal skin cells into nail cells which push forward
1mm/week in fingers; slower in toes
the longer the finger the greater the growth rate

11. Hypodermis

12. Skin Histology Epidermal Derivatives
End Ch 5
Skin Histology
Epidermal Derivatives