layers of skin
epidermis -- epithelium of skin
dermis -- connective tissue of skin
hypodermis -- connective tissue just underneath skin
| Term | Definition |
|---|---|
layers of skin | epidermis -- epithelium of skin
dermis -- connective tissue of skin
hypodermis -- connective tissue just underneath skin |
thick skin | only on palms of hands, front of fingers, soles of feet
no hair and no sebaceous oil glands
high friction |
thin skin | most of body
hair, sebaceous oil glands and sweat glands |
skin functions | trauma and infection resistance
water retention
vitamin d synthesis
thermoregulation |
keratinocytes | synthesize keratin
in many layers of epidermis |
stem cells
| divide, produce keratinocytes
only stratum basale |
melanocytes | make melanin (VIT D PRODUCTION)
stratum basale |
tactile (Merkel) cells | touch receptors -- join w nerves
stratum basale |
dendritic (Langerhans cells)
| immune surveillance
found in stratum spinosum, granulosum |
stratum basale | deepest layer
1 cell thick |
stratum spinosum
| thickest layer of epidermis
several layers of cells |
stratum granulosum | cells have dark granules |
stratum lucidum | ONLY IN THICK SKIN |
stratum corneum | several layer of dead, scaly cells |
layers of epidermis (superficial to deep | stratum corneum, (stratum lucidum) stratum granulosum, stratum spinosum, stratum basale |
papillary layer | superficial, thin layer of dermis
areolar tissue
rich in blood vessels |
reticular layer | deep, thick layer of dermis
dense, irregular connective tissue |
hypodermis | NOT true layer of skin
below dermis
adipose and areolar tissue |