photo.jpg

## Skin Pigments * **Melanin** - produced by melanocytes. * Ranges from yellow to reddish-brown to black. * Responsible for hair and eye color. * Provides protection against UV light. * Freckles are an accumulation of melanin. * Albinism is the absence of melanin. * **Carotene*...

## Skin Pigments * **Melanin** - produced by melanocytes. * Ranges from yellow to reddish-brown to black. * Responsible for hair and eye color. * Provides protection against UV light. * Freckles are an accumulation of melanin. * Albinism is the absence of melanin. * **Carotene** - yellow-orange pigment found in plants. * Accumulates in Stratum corneum. * **Hemoglobin** - gives pinkish red color. * Found in red blood cells. ## Tanning and Sunburns * Exposure to UV light stimulates melanocytes to increase production of melanin. * Melanin builds up to help protect skin against UV radiation. (tan) * A sunburn is the skin reacting to UV exposure. * UV light causes elastic fibers to clump and become leathery. * UV light can alter DNA in cells, causing them to mutate (cancer). ## Skin Color and Diseases 1. **Redness / Erythema**: fever, hypertension, inflammation, allergies, blushing. 2. **Pallor / Blanching**: anemia, low blood pressure, feeling of fear and anger. 3. **Jaundice**: liver disorder (yellow). 4. **Bronzing**: Addison's disease (kidney disease). 5. **Bruising**: broken blood vessels. 6. **Cyanosis**: Bluish or purple colored skin. ## Appendages of the Skin 1. Cutaneous glands 2. Hair 3. Hair follicles 4. Nails ### Cutaneous Glands * Exocrine Glands - releases secretion to the skin via ducts. * 2 groups: 1. **Sebaceous / Oil glands**: found all over the skin except on the palms and soles. * No hair follicle * Sebum / grease product - a mixture of oily substances and fragmented cells. * Sebum lubricates the skin to keep it soft and moist. * Prevents hair from becoming brittle. ## Hair * It is a * It is fo * It is * It is * It is * It is ### Functions of Hair 1. Protection 2. Help to a