Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Appendages of the Skin  Sebaceous glands  Produce oil  Lubricant for skin  Kills bacteria  Ducts on hair follicles  Puberty

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Appendages of the Skin  Sweat glands  Widely distributed  Two types  Eccrine  Open to pore  Apocrine  Open to hair follicle

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Sweat and Its Function  Dissipate excess heat  Excretes wastes  Acidic=kills bacteria

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Appendages of the Skin  Hair  Made by hair bulb  Keratinized epithelial cells  Melanocytes Figure 4.7c

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Associated Hair Structures  Hair follicle  Sheathe around hair root  Arrector pilli  Smooth muscle  What happens when its cold outside? Figure 4.7a

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Appendages of the Skin  Nails  Scale-like modifications of the epidermis  Heavily keratinized  Stratum basale beneath nail bed  Growth

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Nail Structures  Free edge  Body  Root  Cuticle  Why are the lunula colorless? Figure 4.9