BIOL126 Lecture Notes - Lecture 1: Vitiligo, Vasodilation, Epithelium
Document Summary
Recognise the skin (integument) as a body system composed of different organs. Accessory structures: hairs, follicles, sweat glands, sebaceous glands, nails; arrector pili muscles. Two major layers of tissue: the epidermis and dermis. 1. 1. 2. its functions, including: protection, thermoregulation, synthesis, excretion, pigmentation, blood storage, insulation (fat) First line of defence to protect body against external environment, and informs brain about the environment. Intact skin reduces water loss, prevents pathogen entry, and protects against impact, chemicals and uv light. Protection of underlying tissues from impact damage, abrasion, fluid loss and chemicals. Maintenance of normal body temperature via insulation or evaporative cooling. Synthesis of vitamin d3 by uv light and phosphorous from the git. converted to calcitriol by liver for absorption of calcium. Detection of the external environment via thermoreceptors (heat and cold), fine touch receptors, pressure receptors and nociceptors (pain). Production of keratin to protect against abrasion and provide water resistance.
