Lab 6

  1. Epidermis
    the epithelium covering the surface of the skin; is found under keratinized stratified squamous epithelium
  2. Dermis
    the connective tissue layer beneath the epidermis of the skin; includes the papillary and reticular layer
  3. "Hypodermis"
    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
  4. Keratinocytes
    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
  5. Melanocytes
    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))
  6. Stratum corneum
    exposed surface of both thick and thin skin; most superficial (15-30 layers of keratinocytes)
  7. Stratum lucidum
    thick skin of the palms and soles; made up of thin layer of keratin
  8. Stratum granulosum
    region superficial to the __________ (3-5 layers of keratinocytes: more mature)
  9. Stratum spinosum
    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)
  10. Stratum basale
    innermost epidural layer or stratum germinative; basal layer which has basal cells (stem cells) that can become keratinocytes
  11. Papillary layer
    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
  12. Meisner's corpuscle
    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
  13. Reticular layer
    deep to the papillary layer, consists of an interwoven meshwork of dense irregular connective tissue containing both collagen and elastic fibers
  14. Pacinian corpuscle
    an encapsulated ending of a sensory nerve that acts a receptor for pressure and vibration; thicker into skin; press deeper for sense
  15. Cleavage lines of the skin
    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
  16. Sebaceous gland
    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
  17. Sudoriferous gland
    sweat glands
  18. Apocrine gland
    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)
  19. Merocrine gland
    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)
  20. Subcataneous
    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)
  21. Hair follicle
    organs that produce the nonliving structures of hair; made up of keratin; production starts at hair bulb
  22. Arrector pili muscle
    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
  23. Nail body
    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
  24. Nail bed
    area of epidermis
  25. Cuticle
    a portion of the stratum corneum of the nail root extends over the exposed nail; forming the eponychium; protects underlying connective tissue
  26. Melanin
    yellow-brown pigment produced by the melanocytes of the skin
  27. UV radiation
    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
Card Set
Lab 6
Integumentary system, epidermis, dermis, glands, hypodermis, finger nail, importance of pigmentation