Ex 7

stratum basal

layer of epidermis where there is the most rapid cell division; epidermal layer with stem cells

stratum corneum

tough, water-repellent epidermal layer; contains dead squamous-shaped cells

papillary region

areolar connective tissue layer beneath basement membrane

dermal papillae

projections of dermis that cause epidermal ridges

stratum lucidum

translucent layer found in thick skin, absent in thin skin

stratum spinosum

appears to have thorn-like projections in prepared slides

reticular region

thick dermal layer containing dense, irregular CT; dermal layer with hair follicles and glands

stratum granulosum

epidermal layer containing visible granules

dendritic

defends skin against microbes; 2%

keratinocytes

produces keratin; 90%

melanocytes

produces the pigment melanin which shields cell nuclei from UV radiation; 8%

tactile

associated with sensory neurons and functions in sensation of touch; 2%

apocrine

sudoriferous glands located in axillary and genital areas; become active after puberty

dermal papilla

CT projections; provides blood supply for hair matrix

hyponychium

secures nail to digit

hair follicle

epithelial layer that surrounds hair root

sebaceous gland

secretes sebum onto hair and skin

nail body

part of nail that is visible

free edge

part of nail that extends beyond digit

hair bulb

part of hair that contains the matrix

eccrine

sudoriferous glands that deposit sweat onto epidermal ridges causing fingerprints

hair shaft

part of hair in epidermis and extending beyond skin surface

arrector pili

moves hair shaft perpendicular to skin; causes goosebumps

eponychium

thickened epithelial tissue at proximal end of nail body

lunula

crescent-shaped area of nail body near cuticle

hair root

part of hair within dermis

nail root

part of nail within skin

nail matrix

part of nail deep to nail root that produces new cells, causing the nail to grow