CAS BI 106 Lecture Notes - Lecture 4: Stratified Squamous Epithelium, Stratum Corneum, Stratum Granulosum
Document Summary
Integument- means a covering, refers to the organ system made up of the skin, hair and nails: cutaneous- relating to the skin, dermis-a specific layer of the skin (lower, dermatology-the branch of medicine concerned with the skin. Functions of the skin: protection from the outside world (disease etc, control of water loss, temperature regulation, metabolic regulation, nutrient storage/synthesis (vitamin d, sensory reception (how to react to the outside world, excretion. Stratum lucidum: thick skin only, a few rows, the cells appear clear under the microscope. Stratum spinosum: several layers of keratinocytes joined by desmosomes. Cells are beginning to synthesize keratin: several cell layers thick, keratin production begins here, living cells, appear spindly under the microscope. Melanin and skin color: melanocytes produce 2 pigments proteins: carotene (gives orangy yellow tone ex. carrots) and melanin ratio of these two determines exact skin color.
