| Stratum Basale (Basal Layer) | The deepest layer of the epidermis, containing basal cells that are mitotically active, producing new skin cells. |
| Stratum Spinosum (Spiny Layer) | The layer above the basal layer, named for the spiny appearance of cells due to desmosomal connections, providing strength and flexibility. |
| Stratum Granulosum (Granular Layer) | The layer where keratinocytes accumulate granules of keratohyalin, contributing to water retention and barrier function. |
| Stratum Lucidum (Clear Layer) | A thin, transparent layer found only in thick skin, consisting of dead and flattened keratinocytes. |
| Stratum Corneum (Horny Layer) | The outermost layer made of dead keratinocytes that forms a durable, waterproof barrier. |
| Dermis | The supportive layer below the stratum basale, providing nutrition to the epidermis, not an epidermal layer but included for context. |
| Papillary Region | The superficial area of the dermis with projections that increase the surface area of contact with the epidermis. |
| Reticular Region | The deeper part of the dermis providing structural strength and elasticity due to dense connective tissue. |
| Subcutaneous Fatty Tissue | The bottom-most layer acting as insulation, an energy reserve, and cushioning for the skin. |
| Pain Receptors | Free nerve endings that detect painful stimuli. |
| Sweat Glands | Involved in thermoregulation and excretion. |
| Touch Receptors | Allow the sensation of touch. |
| Capillaries | Small blood vessels that supply the dermis with nutrients and oxygen. |
| Pressure Receptors | Sense mechanical changes in the environment. |
| Nail Matrix | The tissue at the base of the nail bed responsible for producing cells that become the nail plate. |
| Proximal Nail Fold | The skin overlapping the nail matrix. |
| Eponychium (Cuticle) | A layer of clear skin along the bottom edge of the finger or toe, protecting new nail from bacterial infections. |
| Nail Bed | The skin beneath the body of the nail, which is rich in blood vessels. |
| Free Edge | The part of the nail that extends beyond the finger or toe. |
| Phalanx (bone of fingertip) | The distal portion of the fingers or toes. |
| Stratum Germinativum | The deepest layer of the epidermis involved in generating new skin cells. |
| Melanocyte | A cell in the stratum basale that produces the pigment melanin, giving skin its color and protecting against UV radiation. |
| Dendritic Cells | Immune cells within the stratum spinosum that respond to pathogens. |
| Basement Membrane | A thin layer that anchors the epidermis to the dermis. |
| Lunula | The whitish half-moon shape at the base of the nail, visible part of the nail matrix. |
| Lateral Nail Fold | The fold of skin at the side of the nail. |
| Hyponychium | The area of sensitive skin under the free edge of the nail plate. |
| Nail Root | The part of the nail under the skin where nail growth begins. |
| Distal Phalanx | The bone beneath the nail bed. |
