Embedded Files
Modification of epidermis
Composed of keratinized epithelial cells
Functions: thermoregulation, communication, and protection
Types of Hair:
Guard hairs (smooth outer coat)
Wool hairs/Undercoat (fine, usually curly)
Tactile Hairs
Innervated
Image credit: Lecture 8
Hair Follicle
Hair Follicle
3 layers:
Medulla
a. innermost layer (💡Medulla = "middle")
Cortex
a. bulk of hair
b. Several layers of cornified cells
Cuticle
a. outermost layer
Hair bulb
surrounds dermal papilla
Internal epithelial root sheath
covers root of hair follicle
External epithelial root sheath
continuous with epidermis
gives rise to sebaceous glands
Arrector pili muscle
Smooth muscle (💡raising hair = involuntary = smooth muscle)
Can straighten/raise hair
Test Yourself:
Test Yourself:
Q: What is hair composed of?
Q: What is hair composed of?
A: keratinized epithelial cells
Q: What are the 3 layers of the hair follicle (superficial to deep)?
Q: What are the 3 layers of the hair follicle (superficial to deep)?
A: Cuticle, Cortex, Medulla
Q: What type of muscle is the arrector pili muscle?
Q: What type of muscle is the arrector pili muscle?
A: Smooth muscle
Page updated
Report abuse