BIOL 4010 Lecture Notes - Lecture 2: Desmosome, Macrophage, Scleroprotein
30 Dec 2020
School
Department
Course
Professor
Document Summary
Skin provides: protection- barriers to uv radiation, mechanical/chemical insults, pathogens, dehydration, thermal regulation, metabolic fxn- synthesis of vitamin d, storage of energy. Structure of skin: epidermis: keratinized, stratified squamous epithelium. Thick skin with 5 layers is found in palms of hands & soles of feet. Has cells called keratinocytes that makes keratin protein. Keratin gives hair, nails & skin strength & makes it waterproof. Keratinocytes are constantly beings replaced: merkel cells: receptor which stimulates nerves and senses touch, melanocytes: produces melanin. Protection against uv light & radiation damage: dermis: blood and lymph vessels, nerves, hair follicles & sweat glands. Has papillary & reticular layer: subcutis (hypodermis): aka subcutaneous. Connects skin to fibrous tissues of bones & muscles. Its vascularized, adipose tissue, fat storage, insulation, cushioning. 4 types of cells: keratinocytes (epidermal cells)- fibrous protein that gives hair, skin & nails hardness & water- resistant properties.
