BIO 3372 Lecture 21: Chapter 21 - Microbial Disease of the Skin and Eyes
Document Summary
Chapter 21 - microbial disease of the skin and eyes. Skin is the body"s rst line of defense against pathogens. Inhospitable environment skin secretions are acidic little moisture. Epidermis- thing outer portion of skin; composed of layers of epithelial cells. Keratin- waterproo ng protein coating outer layer of epidermis. Dermis- inner, thick portion of skin; composed mainly of connective tissue. Perspiration - provides moisture and nutrients for bacterial growth contains salt that inhibits microorganisms contains lysozyme that breaks down bacterial cell walls contain antimicrobial peptides. Sebum a mixture of lipids, proteins and salt is secreted by oil glands to prevent skin and hair from drying out. Structure of human skin two parts - dermis and epidermis passage-ways for pathogens - hair follicles, oil gland ducts, sweat gland ducts. Mucous membranes: line the body cavities open to the exterior. Tightly packed epithelial cells attached to an extracellular matrix cells secrete mucus some cells have cilia.
