Small, Involuntary Muscles In The Base Of The Hair - Practice Materials

Hydrolipidic An oil-water balance that protects the skin's surface. transepidermal water loss Abbreviated TEWL; water loss caused by evaporation on the skin's surface. Barrier function Protective barrier of the epidermis; the corneum and intercellular matrix protect the surface from irritation and dehydration. Intercellular matrix Lipid substances between corneum cells that protect the cells from water loss and irritation. Fibroblasts Cells that stimulate cells, collagen, and amino acids that form proteins. epidermal growth factor Abbreviated EGF; stimulates cells to reproduce and heal. Pores Tube-like opening for sweat glands on the epidermis. follicles are tubelike openings in the epidermis sudoriferous glands glands that secrete sweat to the outside of the body; also assist in body temperature regulation arrector pili muscle Small, involuntary muscles in the base of the hair follicle that cause goose flesh when the appendage contracts, sometimes called goose bumps and papillae. sebum oily substance secreted by sebaceous glands sebaceous glands protect the surface of the skin. appendages connected to follicles. subcutaneous layer adipose (fat) tissue located beneath the dermis; a protective cushion and energy storage for the body reticular layer Deeper layer of the dermis that supplies the skin with oxygen and nutrients Dermis Also known as the derma, corium, cutis, or true skin; support layer of connective tissue, collagen, and elastin below the epidermis. subcutis tissue Also known as adipose tissue; fatty tissue found below the dermis that gives smoothness and contour to the body, contains fat for use as energy, and also acts as a protective cushion for the outer skin. dermal papillae Membranes of ridges and grooves that attach to the epidermis; contains nerve endings and supplies nourishment through capillaries to skin and follicles. papillary layer Outermost layer of the dermis, directly underneath the epidermis Hair Papilla Cone-shaped elevations at the base of the follicle that fit into the hair bulb. The papillae are filled with tissue that contains the blood vessels and cells necessary for hair growth and follicle nourishment. Glycosaminoglycans (GAGs) a water-binding substance such as a polysaccharide (protein and complex sugar) found between the fibers of the dermis collagen Fibrous protein that gives the skin form and strength Elastin A protein that is similar to collagen and is the chief constituent of elastic fibers. lymph vessels Located in the dermis, these supply nourishment within the skin and remove waste. hyaluronic acid Hydrating fluids found in the skin; hydrophilic agent with water-binding properties. keratin a fibrous protein forming the main structural constituent of hair, feathers, hoofs, claws, horns, etc. Keratinocytes Epidermal cells composed of keratin, lipids, and other proteins. epidermis outermost layer of skin; a thin protective layer with many cells, mechanisms, and nerve endings; is made up of 5 layers stratum germinativum also known as the basal cell layer, the deepest live layer of the epidermis that produces new epidermal skin cells and is responsible for growth Melanosomes Pigment carrying granules that produce melanin, a complex protein. melanocytes cells that produce melanin for pigmentation Desmosomes The structures that assist in holding cells together; intercellular connections made of proteins. stratum spinosum layer of the epidermis above the stratum germinativum layer containing desmosomes, the intercellular connections made of proteins Melanin Tiny grains of pigment in the cortex that give natural color to the hair lameller granules epidermal cells composed of keratin, lipids, and other proteins Langerhans immune cells Guard cells of the immune system that sense unrecognized foreign invaders, such as bacteria, and then process these antigens for removal through the lymph system. stratum granulosum a layer of the epidermis that marks the transition between the deeper, metabolically active strata and the dead cells of the more superficial strata Corneocytes Another name for a stratum corneum cell. Hardened, waterproof, protective keratinocytes; these "dead" protein cells are dried out and lack nuclei. stratum lucidum Clear, transparent layer of the epidermis under the stratum corneum. stratum corneum outermost layer of the epidermis, which consists of flattened, keratinized cells Tyrosinase The enzyme that stimulates melanocytes and thus produces melanin. bilayers a thin polar membrane made of two layers of lipid molecules. These membranes are flat sheets that form a continuous barrier around all cells. Pheomelanin a type of melanin that is red and yellow in color; people with light colored skin produce mostly this Eumelanin A type of melanin that is dark brown to black in color. People with dark-colored skin mostly produce this. apocrine glands coiled structures that attach to hair follices found in the genitals and underarms that secrete sweat eccrine glands glands that produce sweat; found over most of the body T-cell Identify molecules that have foreign peptides and also help regulate immune response. Leukocytes white blood cells, fight infection Ceramides Glycolipid materials that are a natural part of skin's intercellular matrix and barrier function. UVA radiation Also known as aging rays; longer wavelengths ranging between 320 to 400 nanometers that penetrate deeper into the skin ; cause genetic damage and cell death.contributes up to 95 percent of the sun's ultraviolet radiation. UVB radiation Also known as burning rays;wavelengths range between 290 to 320 nanometers. have shorter, burning wavelengths that are stronger and more damaging; causes burning of the skin as well as tanning, skin aging, and cancer. Glycation Caused by an elevation in blood sugar, the binding of a protein molecule to a glucose molecule resulting in the formation of damaged, nonfunctioning structures, known as Advanced G******** End products( a.k.a. AGES); alters protein structures and decreases biological activity. Couperose redness; capillaries that have been damaged and are now larger, or distended, blood vessels; commonly seen with telangiectasia High-Energy Visible Light