Skin Flashcards
Stratum corneum
Dead cells
Thickest in areas of body that have hair
Size inversely proportional to stratum lucidum
Replace organelles and cytoplasm with waterproof proteins
Filled with keratin (cannot form calluses)
5 Layers of the Epidermis
Stratum corneum Stratum lucidum Stratum granulosum Stratum spinosum Stratum basale
Keratin
Fibrous protein found in scales, horns, hooves, beaks, and claws
Stratum lucidum
Dead cells
Thickest in palms of hands and soles of feet
Size inversely proportional to stratum corneum
Replace organelles and cytoplasm with waterproof proteins
Filled with eleidin
Eleidin
Builds up in cells, making them thicker, tougher, and harder - forms calluses
Stratum granulosum
Living AND dead cells
Stratum spinosum
Living cells
Contains melanocytes
Vitamin D
Co-enzyme that facilitates movement of calcium ions into the bones
Produced when melanocytes are exposed to sunlight
More pigment –> slower rate of vitamin D production
Rickets
Medical condition resulting from vitamin D deficiency
Stunted growth, weak bones
Greatest effect on children
Adults with rickets have misshapen bones and bowl legs
Food is fortified with vitamin D to prevent rickets
PDGF
Platelet-derived growth factor
Does the epidermis contain nerve endings?
No
Stratum basale
Living cells
Connects the epidermis to the dermis
Where all epidermal cells originate
Contains dermal papillae
Dermal papillae
Creates fingerprints
Increased surface area –> greater number of attachment points to hold epidermis firmly in place connected to the dermis
Prevents the loss of the skin’s protective layer
Has hard side and soft side (Velcro!)
How does the epidermis grow?
From the inside out
From stratum basale up to the stratum corneum
Melanocytes
Cells that make pigment called melanin Everyone has the same number of melanocytes that produce different amounts of melanin Where skin cancer begins Make vitamin D Determine skin color
