BIOL 2021 Lecture Notes - Lecture 1: Dense Irregular Connective Tissue, Basal-Cell Carcinoma, Autotransplantation

• School: University of Windsor
• Department: Biological Sciences
• Course: BIOL 2021
• Professor: Sara Mcnorton

Document Summary

Epidermis keratinized stratified squamous epithelium that contains keratinocytes, melanocytes, tactile epithelial cells and dendritic cells. In thick skin, there are 5 layers and in thin skin there are only 4. Stratum basale deepest layer, firmly attached to underlying dermis at wavy borderline: consists of a single row of cells, mostly stem cells that produce keratinocytes, tactile epithelial cells, merkel cells, are distributed sparsely among keratinocytes. Associated with disc-like nerve ending and are receptors for touch: contain melanocytes which produce the dark skin pigment melanin. Melanin is made in membrane-walled granules and transferred to keratinocytes through cell processes. Melanin clusters on superficial side of keratinocytes to protect from uv radiation. Stratum lucidum occurs in thick skin, consists of a few rows of flat, dead keratinocytes. Stratum corneum most external part, many cell layers thick: contains dead keratinocytes that are flat sacs completely filled with keratin, cells from this layer are shed regularly as dandruff and skin flakes.