SKIN

SKIN

1. Structure

   • Epidermis
     • Layers
       • Stratum corneum
       • Stratum lucidum
         • Only present in thick areas of skin
           • palms / soles of feet
       • Come Lets Get Sun Baked
       • Stratum granulosum
       • Stratum spinosum
       • Stratum basale
     • Stratified squamous epithelium
     • Cell types
       • Keratinocytes
         • Produce keratin
           • waterproofs the skin
       • Melanocytes
         • Produce pigment
         • Same number of cells in everyone
       • Langerhans cells
         • Dendritic cell, can become APC
       • Merkel cellls
         • Sensory
           • very sensitive to touch
       • Epidermal stem cells
         • in basale layer
   • Dermis
     • Blood vessels
     • Nerves
     • Layer of connective tissue
     • Hair, nails, sebaceous and sweat glands ORIGINATE here
   • Hypodermis
     • Fat

2. Function

   • Barrier (protection)
     • keratin
     • hydrophobic lipid layer in granulosum
     • cornified layer in corneum
   • Immunity
     • change in pH as you get deeper in layers of corneum (less acidic)
     • Langerhan cells in spinosum
   • Sense organs
     • Thermoreceptors
     • Meissner's corpuscles
       • senses touch
         • situated quite superficial
     • Nociceptors
     • Pacinian corpuscles
       • pressure sensors
         • situated very deep
   • Vitamin D production
   • Beauty, shape

3. Histology