Chapter 10 : Physiology and Histology of the Skin Flashcards
Apocrine glands
Coiled structures attached to hair follicles found in the under arm and genital areas that secrete sweat.
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.
Barrier function
Protective barrier of the epidermis; the corneum and intercellular matrix protect the surface from irritation and dehydration.
Ceramides
Glycolipid materials that are a natural part of skin’s intercellular matrix and barrier function.
Collagen
Fibrous, connective tissue made from protein; found in the reticular layer of the dermis; gives skin its firmness; a large, long-chain molecular protein that lies on top of the skin and binds water
Corneocytes
Another name for a stratum corneum cell; hardened, waterproof, protective keratinocytes; “dead” protein cells are dried out and lack nuclei.
Dermal papillae
Membranes of ridges and grooves that attach to the epidermis; contains nerve endings and supplies nourishment through capillaries to skin and follicles.
Dermis
Support layer of connective tissue, collagen, and elastin below the epidermis
Desmosomes
The structures that assist in holding cells together; intercellular connections made of proteins.
Eccrine glands
Sweat glands found all over the body with openings on the skin’s surface through pores; not attached to hair follicles, secretions do not produce an offensive odor.
Elastin
Protein fiber found in the dermis; gives skin its elasticity and firmness.
Epidermal growth factor (EGF)
Stimulates cells to reproduce and heal.
Epidermis
Outermost layer of the skin; a thin protective layer with many cells, mechanisms, and nerve endings.
- Stratum corneum
- Stratum lucidum
- Stratum granulosum
- Stratum spinosum
- Stratum germinativum
Fibroblasts
Cells that stimulate cells, collagen, and amino acids that form proteins.
Follicles
Hair follicles and sebaceous follicles are tube-like openings in the epidermis.
Eumelanin
A type of melanin that is dark brown to black in color.
Glycation
Caused by an elevation in blood sugar, glycation is the binding of a protein molecule to a glucose molecule resulting in the formation of damaged, nonfunctioning structures called Advanced Glycation End products (AGEs)
Hair papillae
Cone-shaped elevations at the base of the follicle that fit into the hair bulb.
Hyaluronic acid
Hydrating fluids found in the skin; hydrophilic agent with water binding properties.
Hydrolipidic
Hydrolipidic film is an oil-water balance that protects the skin’s surface.
Intercellular matrix
Lipid substances between corneum cells that protect the cells from water loss and irritation.
Keratin
Fibrous protein of cells that is also the principal component of skin, hair, and nails.
Keratinocytes
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.
Leukocytes
White blood cells that have enzymes to digest and kill bacteria and parasites; also respond to allergies.
Lymph vessels
Located in the dermis, these supply nourishment within the skin and remove waste.
Melanin
Tiny grains of pigment that are produced by melanocytes and deposited into cells in the stratum germinativum layer of the epidermis and in the papillary layers of the dermis.
Melanocytes
Cells that produce skin pigment granules in the basal layer.
Melanosomes
Pigment carrying granules that produce melanin, a complex protein.
Papillary layer
Top layer of the dermis next to the epidermis.
Pheomelanin
A type of melanin that is red and yellow in color, People with light colored skin mostly produce this.
Pores
Tube-like opening for sweat glands on the epidermis.
Reticular Layer
Deeper layer of the dermis that supplies the skin oxygen and nutrients; contains fat cells, blood vessels, sudoriferous (sweat) glands, hair follicles, lymph vessels, arrector pili muscles, sebaceous (oil) glands and nerve endings.
Rosacea
Chronic condition that appears primarily on the cheeks and the nose and is characterized by flushing (redness), telangiectasis
Sebaceous glands (oil glands)
Protect the surface of the skin; connected to follicles.
Sebum
Oil that privides protection for the epidermis from external factors and lubricates both the skin and hair.
Stratum corneum (Horny layer)
Outermost layer of the epidermis, composed of corneocytes.
Stratum germinativum (Basal cell layer)
Active layer of the epidermis above the papillary layer of the dermis; cell mitosis takes place here that produces new epidermal skin cells and is responsible for growth.
Stratum granulosum (Granular layer)
layer of the epidermis composed of cells filled with keratin that resemble granules; replaces cells shed from the stratum corneum.
Stratum lucidum
Clear, transparent layer of the epidermis under the stratum corneum; thickest on palms of hands and soles of feet.
Stratum spinosum (Spiny layer)
Layer of the epidermis above the stratum germinativum layer containing desmosomes.
Subcutaneous layer (Hypodermis)
Subcutaneous adipose (fat) tissue located beneath the dermis; a protective cushion and energy storage for the body.
Subcutis tissue (adipose tissue)
Fatty tissue found below the dermis that gives smoothness and contour to the body, contains fat for use as energ, and also acts as a protective cushion for the outer skin.
Sudoriferous glands (sweat glands)
Excrete perspiration, regulate body temperature, and detoxify the body by excreting excess salts and unwanted chemicals.
T-cells
Identify molecules that have foregin peptides and also help regulate immune response.
Telangiectasia (couperose skin)
Cappillaries that have been damaged and are now larger, or distended, blood vessels
Transepidermal water loss (TEWL)
Water loss caused by evaporation on the skins surface.
Tyrosinase
The enzyme that stimulates melanocytes and thus produces melanin.
UVA radiation (aging rays)
longer wavelengths ranging between 320 to 400 nanometers that penetrate deeper into the skin than UVB; cause genetic damage and cell death.
UVB radiation (burning rays)
UVB wavelenghts range between 290 to 320 nanometers, UVB rays have shorter, burning wavelengths that are stronger and more damaging than UVA rays.
