HLTH108 Lecture 9: Skin

• School: Macquarie University
• Department: Health
• Course: HLTH108
• Professor: Stephanie Marhoff-Beard

Document Summary

26th march 2018: lecture 9 skin: functions of skin: Protects from impact, friction and uv rays. External layer is relatively impermeable to water. Receptor organ for touch, heat, pressure and pain: main layers of skin, epidermis: stratified squamous keratinized epithelium, dermis: deeper connective tissue with embedded structures] Enzymes remove cell organelles = forms closely packed pates = tough, waterproof layer. 3-5 layers of flattened polygonal (many sided) keratinocytes with cytoplasm filled with coarse basophilic granules. Small lamellar granules = fuse with cell membrane = discharge their contents into intercellular spaces = forming lipid rich sheets (barrier to penetration and seals the skin) Thick in areas of friction and pressure. Rests on the basement membrane at the dermal junction. Abundant cytoplasm with numerous processes extending into spaces between keratinocytes. Melanin = gives skin colour, blocks uv radiation. Passes along the cytoplasmic processes to the basal and spinosum cell layer of keratinocytes. Present in small numbers of healthy skin.