Anatomy and Cell Biology 2221 Lecture Notes - Lecture 2: Stratum Basale, Stratified Squamous Epithelium, Venous Plexus
9 Dec 2016
School
Department
Professor
Document Summary
Consists of two major layers: epidermis can see with eyes, dermis lies under epidermis. Skin and subcutaneous layer form the integument. Protects body from external environment bacteria, viruses. Excretes and absorbs substances can be negative because very permeable. Papillae, connective tissue, bleeding breaks dermal layer. Weighs 10-11 lbs, variable organ in terms of diameter. Up to 5% of total blood volume resides in skin at a given time. The epidermis has a number of important characteristics: Contains four major types of cells: keratinocytes. Melanocytes: intraepidermal macrophage or langerhans, tactile epithelial. Keratinocytes make up about 90% of these cells. Intraepidermal immune system, roam throughout looking for bacteria and damaged cells to clean up. Tactile respond to pressure, pain, temperature. Dead layers rise to surface to help prevent damage. Damage to epidermis wont leave permanent damage to skin. Damage to dermis will leave permanent mark on skin (tattoos) Epidermal ridges (finger prints) don"t change because papillary regions go deep into dermis.
