A&P Chapter 5

  1. What layer of the skin is vascularized?
    Only the dermis
  2. Keratinocytes
    • Chief role is to produce keratin: the fibrous protein that helps give the epidermis its protective properties
    • connected to one another by desmosomes
    • arise in the deepest part of the epidermis (stratum basale)
    • undergo continuous mitosis
  3. Melanocytes
    • Synthesize the pigment melanin
    • spider shaped epithelial cells
    • found in the deepest layer of epidermis
  4. Merkel disc
    functions as a sensory receptor for touch
  5. Langerhans cell
    • Epidermal dendritic cell
    • ingest foreign substances and are key activators of our immune system
  6. What are the layers of the skin?
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    • Stratum Basale: single row of stem cells - a continually renewing cell population
    • Stratum Spinosum: web like system of intermediate filaments, mainly tension resisting bundles of pre-keratin filaments
    • Stratum Granulosum: consists of 3-5 cell layers in which keratinocytes appearance changes drastically and the process of keratinization begins
    • Stratum Lucidum: Only in thick skin
    • Stratum Corneum: outer most 20-30 layers; provides a durable overcoat
  7. What are the two layers of the dermis?
    • Richly supplied with nerve fibers, blood vessels, and lymphatic vessels.
    • Paillary: areolar connective tissue; friction ridges
    • Reticular: 80% of the thickness of the dermis
  8. What are the three major skin markings?
    • Friction ridges: increase friction and enhance the gripping ability of the fingers and feet
    • Cleavage / tension lines: separations or less dense regions between bundles of connective tissue
    • Flexure lines: dermal folds that occur at or near joints, where the dermis is tightly secured to deeper structures (deep creases in the palm).
  9. What three pigments contribute to skin color?
    • Melanin: color ranges from yellow to tan to yellowish brown; found only in the deeper layers of the epidermis; freckles and moles are local accumulations of melanin
    • Carotene: accumulates in the stratum corneium and in fatty tissue of the hypodermis; yellowish tinge of the skin
    • Hemoglobin: pinkish hue of fair skin reflects the crimson color of the oxygenated pigment in RBC's.
  10. Sudoriferous glands
    • Sweat glands
    • Merocrine sweat glands with the secretory part coiled deep in the dermis
    • Secretory cells are associated with myoepithelial cell's - specialized cells that contract when stimulated by the nervous system
    • major role is to prevent overheating of the body
  11. Apocrine sweat glands
    • merocrine glands that secrete their product by exocytosis
    • Their ducts empty into hair follicles
  12. Ceremonious Glands
    modified apocrine glands found in the lining of the external ear canal
  13. Sebaceous glands
    • simple branched alveolar glands that are found all over the body except in the thick skin of the palms and soles
    • Secrete sebum
  14. Vellus hair
    body hair of children and and adult females
  15. Terminal hair
    Coarser, longer hair of the eyebrows and scalp
Card Set
A&P Chapter 5
The integumentary System