Skin Color Pigments

Skin Color Pigments  ______produced in epidermis by melanocytes  same # of melanocytes in everyone, but differing amounts of ______produced  results vary from yellow to tan to black color  ______convert ______to melanin  UV in sunlight increases melanin production

 ______in dermis  yellow-orange pigment (precursor of vitamin A)  found in stratum ______& ______

 ______ red, ______in blood cells  if other pigments are not present, epidermis is translucent so pinkness will be evident  Clinical observations  ______or liver spots = melanocytes in a patch  ______= inherited lack of tyrosinase; no pigment  ______= autoimmune loss of melanocytes in areas of the skin produces white patches Skin Color as Diagnostic Clue  ______ yellowish color to skin and whites of eyes  buildup of yellow ______in blood from liver disease  Cyanotic  bluish color to nail beds and skin  hemoglobin depleted of oxygen looks purple-blue  ______ ______of skin due to enlarged capillaries in dermis  during inflammation, infection, allergy or burns

Accessory Structures of Skin  Epidermal derivatives  Cells sink inward during development to form:  ______ ______ ______ ______Functions of Hair  Prevents ______ Decreases ______ ______help protect eyes  Touch receptors (hair root plexus) senses light touch Structure of Hair  ______ visible  medulla, cortex & cuticle  CS round in straight hair  CS oval in wavy hair  ______ below the surface  ______ surrounds root  external root sheath  internal root sheath  base of follicle is bulb  blood vessels  germinal cell layer Hair-Related Structures  ______ ______muscle in dermis contracts with cold or fear.  forms goosebumps as hair is pulled vertically  ______ detect hair movement Hair Color  Result of ______produced in melanocytes in hair bulb  Dark hair = true melanin  Blond and Red = melanin with ______and ______added  Graying = decline in melanin production  White hair = air bubbles in ______

Sebaceous (Oil) Glands  Secretory portion in the dermis  Most open onto ______ ______ combination of ______, proteins, fats & ______ keeps hair and skin soft & pliable  inhibits growth of ______& ______(ringworm)  ______ bacterial inflammation of glands  secretions stimulated by ______at puberty

Sudoriferous (Sweat) Glands  ______(sweat) glands  most areas of skin  secretory portion in dermis with duct to surface  regulate body temperature with perspiration

 ______(sweat) glands  ______and ______region  secretory portion in dermis with duct that opens onto hair follicle  secretions more viscous (milky)

Ceruminous Glands  Modified sweat glands produce ______secretion in ______ ______contains secretions of oil and wax glands  Helps form barrier for entrance of foreign bodies  Impacted cerumen may reduce hearing

Structure of Nails  Tightly packed, ______cells  Nail body  visible portion pink due to underlying ______ free edge appears white  Nail root  buried under skin layers  ______is white due to thickened stratum basale  ______(cuticle)  stratum corneum layer  Nail Matrix  deep to the nail root where growth occurs  Growth is 1mm per week--faster in summer & on most-used hand