SKIN is IN Objective To learn the structure

SKIN is IN! Objective: To learn the structure and function of the Integumentary System 1. On the surface of your fingers are unique little ridges, called fingerprints. What do you think is their purpose? 2. Are any two sets of fingerprints alike? Explain. © 2014 Getting Nerdy, LLC

Made up of the hair, nails, and skin © 2014 Getting Nerdy, LLC

HAIR: - Made of the protein “keratin, ” grows from follicle - Found all over body except lips, palms and soles of feet - Functions in warmth, protection, and immune defense - Characteristic of mammals Epidermis Hair Shaft Oil Gland Muscle Dermis © 2014 Getting Nerdy, LLC Follicle

NAILS: - Made of the protein “keratin, ” grows from root - Found on fingers and toes (phalanges) - Functions in protection and as a tool for precise activities Root © 2014 Getting Nerdy, LLC Lunula Matrix Nail Plate Nail Bed Free Margin

SKIN: Your skin is the largest organ of your body and is made up of three layers of tissue: 1. Epidermis: outer layer composed of epithelial cells a. Outermost cells are dead and rub off b. New cells are constantly made at the base/bottom of the epidermis. c. Melanocytes: cells produce melanin - pigment that protects your skin and gives it color 2. Dermis: the middle layer composed of connective tissue a. Contains blood vessels, nerve fibers, muscles, oil, sweat glands, and other structures. 3. Hypodermis (fatty layer): below the dermis - insulates body © 2014 Getting Nerdy, LLC

EPIDERMIS Human Skin Cross-section magnified 100 x © 2014 Getting Nerdy, LLC

Skin Cross-section 1. 2. 3. 4. 5. 6. 7. 8. Epidermis Dermis Hypodermis Hair

FUNCTION: 1. Forms a protective covering over the body which prevents infection and water loss 2. Sense our environment through touch 3. Formation of Vitamin D during exposure to the sun © 2014 Getting Nerdy, LLC