Lab 6

the epithelium covering the surface of the skin; is found under keratinized stratified squamous epithelium

the connective tissue layer beneath the epidermis of the skin; includes the papillary and reticular layer

the layer of loose connective tissue below the dermis; also called the subcutaneous layer or superficial fascia; includes blood vessels, adipose, areolar connective tissue, arteries, and veins

the body's most abundant epithelial cell; form several layers and contain large amounts of the protein keratin; house and derived from basal cells in deepest layer of epithelium

a specialized cell in the deeper layers of the stratified squamous epithelium of the skin; responsible for the production of melanin (which gives skin its color --> the brown transfers to keratinocytes (adapted by lysosomes or surface of the skin))

exposed surface of both thick and thin skin; most superficial (15-30 layers of keratinocytes)

thick skin of the palms and soles; made up of thin layer of keratin

region superficial to the __________ (3-5 layers of keratinocytes: more mature)

each time a stem cell divides, one of the daughter cells is pushed superficial to the stratum basale into the __________; looks like miniature pincushions in standard histological sections (8-10 layers of keratinocytes bound by desmosomes)

innermost epidural layer or stratum germinative; basal layer which has basal cells (stem cells) that can become keratinocytes

consists of areolar tissue, contains the capillaries, lymphatics, and sensory neurons that supply the surface of the skin; derives its name from the dermal papillae that project between the epidermal ridges

sensory nerve that is sensitive to mechanical stimuli, found in the dermis in various parts of the body; sense light touch (superficial); found in dermal papillae

deep to the papillary layer, consists of an interwoven meshwork of dense irregular connective tissue containing both collagen and elastic fibers

an encapsulated ending of a sensory nerve that acts a receptor for pressure and vibration; thicker into skin; press deeper for sense

most of the collagen and elastic fibers at any location are arranged in parallel bundles oriented to resist the forces applied to the skin during normal movement

glands that secrete sebum; normally associated with hair follicles; associated with holocrine secretions (cell burst open); as cells mature --> produces lipids; arrector pili contracts --> glands release product from hair follicle; sebum lubricates and makes the hair waterproof; inhibits bacteria

sweat glands

in the armpits (axillae), around the nipples, and in the pubic region; secrete their products into their follicles; coiled, tubular glands produce a sticky, cloudy, and potentially odorous secretion; controlled by nervous system and hormone control; deeply embedded into dermal layer; secrete through ducts --> holocrine secretion (material being released)

also known as eccrine sweat glands; coiled, tubular glands that discharge their secretions directly onto the surface of the skin; far more numerous and widely distributed than apocrine sweat glands; located everywhere else; sweat in pores and ducts --> secretes sweat; controlling temperature and cool off body; secrete water and electrolytes; provide protection from hazards (environmental like pollution)

situated or applied under the skin; anchoring epidermis and dermis in place; areolar connective tissue; drugs will have been all over hair (along lines of vascular)

organs that produce the nonliving structures of hair; made up of keratin; production starts at hair bulb

bundle of smooth muscle cells, which extends from the papillary layer of the dermis to the connective tissue sheath surrounding the hair follicle; in dermis and epidermis

visible portion of the nail covers an area of epidermis called the nail bed; recessed deep to the level of the surrounding epithelium and is bordered on either side by lateral nail grooves and later nail folds; made up of keratin cells

area of epidermis

a portion of the stratum corneum of the nail root extends over the exposed nail; forming the eponychium; protects underlying connective tissue

yellow-brown pigment produced by the melanocytes of the skin

harmful effects of sunlight; a small amount is beneficial because it stimulates the epidermal production of a compound required for calcium ion homeostasis; can damage DNA, causing mutations and promoting the development of cancer; if reached stratum basale --> causes carcinoma (not as important as melanoma), but should be removed