| A | B |
|---|
| Functions of skin | excretion and absorption, protection, vitamin production, temperature regulation, blood reservoir, cutaneous sensations |
| epidermis | outer layer of skin |
| dermis | second layer of skin |
| subcutaneous layer | underneath the dermis, connective tissue |
| keratinocyte | produces the protein keratin, the main protein found in skin, hair and nails |
| melanocyte | produces the pigment melanin, protects the DNA from UV light |
| merkel cell | associated with a touch receptor |
| Langerhans cell | cell associated with the immune system |
| stratum corneum | outer layer of dead cells in the epidermis |
| stratum lucidum | second layer of epidermis, found only in palms of hands and feet |
| stratum granulosum | third layer of epidermis, many keratinocytes found here, undergoing apoptosis (cell death) |
| stratum spinosum | fourth layer of epidermis, some cells towards the bottom still dividing |
| stratum basale | deepest layer of epidermis, some cells are stem cells undergoing division to produce new cells. |
| sebaceous glands | produce an oily secretion called sebum, protects skin, keeps it pliable and softens hair |
| sudoriferous fglands | sweat glands, two types eccrine and apocrine |
| ceruminous glands | produces cerumin, ear wax |
| lameller granules | lipid secretion that gives skin waterproofing |
