BIO E121 Lecture Notes - Lecture 15: Stretch Marks, Subcutaneous Tissue, Melanin
Document Summary
Protects against bacteria & harmful particles, uv radiation, and physical and chemical stress. Prevents excessive water loss due to protein keratin in its outermost cell layer. Elasticity of the dermis produces stretch marks. Discuss the location function and features of the hypodermis. Location: underneath dermis above organ system that it is anchored to. List the factors that can contribute to pigment in the skin. Distribution & quantity of the pigment melanin. 2 forms: yellow to red & black to brown. Under the dermis and epidermis and are not considered to be part of the integument. Structure: everywhere except palms & sole of feet. Sweat glands function: sweat to maintain body temperature and get rid of waste. Discuss the effects of uv light on skin. Uv radiation causes melanocytes to increase production of melanin. Melanin absorbs the radiation which damages deeper cell layers causing skin cells to grow and divide uncontrollably, creating a tumor.
