HAIR

WHAT DOES IT DO?

• Guards head against bumps
• Helps with gender identity
• Shields eyes and respritory tract
• Transmits sensory information

WHAT MAKES IT UP?

• Follicle
• Shaft, cuticle, cortex, medulla
• Outer root sheath
• Glassy membrane
• Connective tissue sheath.

WHAT IS IT?

• Flexible epithelial structure
• Cortex makes up hair shaft
• Cuticle: overlapping scales
• Pigment is distributed by the medulla
• Dead

DO WE NEED IT?

• Warmth
• Protection
• Physical appearance

HOW DOES IT GROW?

• Appendages, eyelashes, and brows grow every 35-40 days
• Scalp .3-.4 mm/day; 6 inches a year
• The more circular shaft, the straighter the hair
• The more elliptical, the curlier
• Cross sectional shape, the shinier

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