Acne: A skin condition that typically occurs on the face and back which are areas rich in sebaceous (oil) glands.

Adipocytes: Fat-storing cells found in the hypodermis.

Adipose: A type of tissue that stores fat for energy and insulation.

Aesthetician: A skincare professional who provides cosmetic treatments such as facials and skin exfoliation.

Albinism: A genetic disorder that completely or partially affects the color of the skin, hair, and eyes due to the inability of melanocytes to produce melanin.

Alopecia: The medical term for hair loss in areas where hair normally grows.

Angiogenesis: The formation of new blood vessels, essential for wound healing.

Apocrine sweat gland: A sweat gland found in the armpits and groin, producing a thicker secretion.

Arrector pili muscle: A small muscle attached to hair follicles that causes hair to stand upright when contracted.

Avascular: Lacking blood vessels, as seen in the epidermis.

Basal cell: A type of cell in the stratum basale that continuously divides to form new skin cells.

Basal cell carcinoma: A form of skin cancer that affects the stem cells in the stratum basale layer of the epidermis.

Burn: Skin damage caused by intense heat, radiation, electricity, or chemicals.

Callus: A thickened area of the epidermis due to constant rubbing or abrasion.

Ceruminous (wax) glands: Glands in the ear that produce earwax.

Convection: The transfer of heat through the movement of air or liquid around the skin.

Cornification: The process by which keratinocytes harden to form the stratum corneum.

Cosmetologist: A professional trained in beauty treatments, including hair, skin, and nail care.

Corn: A specialized form of a callus formed by abrasions on the skin that result from an elliptical-type motion.

Cyanosis: A bluish discoloration of the skin caused by poor oxygenation.

Cuticle: The thin layer of skin at the base of the nail.

Dandruff: A condition of flakes of dead skin from the scalp.

Dehydration: A condition in which the body loses more water than it takes in, affecting skin elasticity.

Dermal papillae: Finger-like projections in the dermis that increase surface area for nutrient exchange with the epidermis.

Dermatologist: A medical doctor specializing in dermatology.

Dermatology: The medical specialty focused on diagnosing and treating skin, hair, and nail disorders.

Dermis: The thick layer of skin beneath the epidermis, containing nerves, blood vessels, and connective tissue.

Eccrine sweat gland: A gland that produces sweat for temperature regulation.

Eczema: An allergic reaction that appears as dry, itchy patches of skin resembling rashes.

Elastin fibers: Protein fibers in the dermis that provide skin elasticity.

Epidermis: The outermost layer of the skin, providing a protective barrier.

Epithelialization: The process by which new skin cells cover a wound.

Eponychium: Another term for the cuticle, protecting the nail matrix.

Erythema: Redness of the skin due to increased blood flow.

Esthetician: Another term for an aesthetician, primarily focused on non-medical skincare treatments.

Fascia: A fibrous tissue that encloses muscles and organs.

First degree burn: A superficial burn that affects only the epidermis.

Fourth degree burn: Burn affecting the underlying muscle and bone.

Freckles: Patches of melanin determined by genetics.

Full thickness burns: Burns that extend fully into the epidermis, dermis, and hypodermis destroying the tissue and affecting the nerve endings and sensory function.

Granulation tissue: New connective tissue and tiny blood vessels that form during wound healing.

Hair follicle: The structure in the skin that produces hair.

Hair root: The part of the hair embedded in the follicle.

Hair shaft: The visible part of the hair above the skin surface.

Hemoglobin: A protein in red blood cells that carries oxygen and contributes to skin color.

Hemostasis phase: The initial phase of wound healing, where clotting occurs to stop bleeding.

Hirsutism: The medical term for excessive hair growth in areas where hair is usually minimal or absent.

Hives: Circular, fluid-filled, itchy, raised lesions, often due to an allergic reaction.

Hyperhidrosis: A medical condition of excessive sweating that is not related to heat or exercise.

Hyponychium: The skin under the free edge of the nail that provides a seal against infections.

Hypodermis: The layer beneath the dermis that contains fat and connective tissue.

Inflammatory phase: The second phase of wound healing, where the body fights infection and clears debris.

Integumentary system: The organ system that includes the skin, hair, nails, and associated glands, serving as a protective barrier for the body.

Jaundice: Yellowing of the skin and eyes due to excess bilirubin.

Keratin: A tough, fibrous protein that strengthens hair, skin, and nails.

Keratinocyte: The primary cell type in the epidermis that produces keratin.

Laceration: An irregular tear or cut of the skin that may require suturing or other type of surgical repair.

Langerhans cells: Immune cells in the epidermis that help fight infection.

Maturation phase: The final phase of wound healing, where collagen strengthens and scars form.

Meissner corpuscles: Sensory receptors in the skin that detect light touch.

Melanin: A pigment that provides color to the skin and protects against UV radiation.

Melanocytes: Cells in the epidermis that produce melanin.

Melanoma: Cancer characterized by the uncontrolled growth of melanocytes, the melanin-producing cells in the epidermis.

Merkel cell: A specialized skin cell that detects touch.

Merkel cells: Sensory cells in the stratum basale that detect touch.

Meissner corpuscle: A sensory receptor that detects light touch.

Metastasize: Spread to other areas of the body.

Moles: Large masses of melanocytes that are usually benign, but should be monitored for changes that could indicate the presence of skin cancer, also known as nevi.

Nail bed: The area of skin beneath the nail that supplies nutrients and support.

Nail body: The hard, visible part of the nail.

Nail root: The part of the nail beneath the skin where new nail growth occurs.

Necrosis: Tissue death.

Nevi: Large masses of melanocytes that are usually benign, but should be monitored for changes that could indicate the presence of skin cancer, also known as moles.

Nociceptors: Pain receptors in the skin.

Pacinian corpuscle: A sensory receptor that detects deep pressure and vibration.

Pallor: Unusual paleness of the skin due to reduced blood flow.

Papillary layer: The upper layer of the dermis with loose connective tissue and dermal papillae.

Pressure injuries: Caused by constant pressure on bony areas that reduce blood flow and lead to tissue injury, also known as  pressure ulcers, decubitus ulcers, and bedsores.

Proliferative phase: The third phase of wound healing, where new tissue forms to replace the wound.

Psoriasis: A skin condition in which keratinocytes in the epidermis divide and move too quickly to the surface, resulting in patchy, scaly build-ups on the skin.

Reticulated: Arranged in a net-like pattern, as seen in the collagen fibers of the reticular layer.

Reticular layer: The deeper layer of the dermis, composed of dense connective tissue.

Sebaceous (oil) gland: A gland that secretes sebum to lubricate and protect the skin.

Sebum: An oily substance produced by sebaceous glands to keep skin moisturized.

Second degree burn: Referred to as a partial thickness burn, affects both the epidermis and a portion of the dermis.

Shingles: A painful rash that occurs along nerves and is caused by reactivation of the varicella-zoster virus.

Stratum basale: The deepest layer of the epidermis, where new skin cells are produced.

Stratum corneum: The outermost layer of the epidermis, composed of dead, keratinized cells.

Stratum granulosum: A layer of the epidermis where keratinocytes begin to die and accumulate keratohyalin granules.

Stratum lucidum: A thin, translucent layer of the epidermis found only in thick skin.

Stratum spinosum: A layer of the epidermis that provides structural integrity and contains Langerhans cells.

Striae: When the dermis is stretched beyond its limits of elasticity, often due to rapid weight gain during puberty and pregnancy. They often appear on the hips and abdomen and initially have a reddish color, but lighten over time. Commonly called stretch marks.

Subcutaneous layer: Another name for the hypodermis.

Superficial fascia: The connective tissue layer that separates skin from underlying muscles and bones.

Squamous cell carcinoma: The second most common skin cancer, affecting the keratinocytes of the stratum spinosum, and usually appears as lesions on the scalp, ears, and hands.

Thermoreceptors: Sensory receptors that detect temperature changes.

Thick skin: Skin found on the palms and soles, with extra layers for protection.

Thin skin: Skin that covers most of the body and has fewer epidermal layers.

Third degree burns: Referred to as full thickness burns that extend fully into the epidermis, dermis, and hypodermis destroying the tissue and affecting the nerve endings and sensory function.

Tinea: Group of skin diseases caused by a fungus, types include ringworm, athlete’s foot, and jock itch.

Translucent: Allowing light to pass through but not detailed images, as seen in the stratum lucidum.

Urticaria: Circular, fluid-filled, itchy, raised lesions, often due to an allergic reaction

Vitiligo: A skin condition in which melanocytes in some areas lose their ability to produce melanin resulting in lighter patches of skin.

Wart: An uncontrolled growth of epidermal cells caused by the papilloma virus.