Integuments

• Fish skin section unicellular in epidermis

  club cells - sensing cells, trigger fear/alarms fish
• Fish skin section unicellular in epidermis

  granular cells - secretes distasteful taste as a protective mechanism
• Fish skin section dermis

  associated with blood vessels and nerve fibers

  subcutaneous muscle
• Fish skin section multicellular cells

  Photophores - deep sea fishes, teleost
• Fish skin section multicellular cells

  Slime gland - lamprey, hagfish
• Fish skin section multicellular cells

  poison gland - secretes poision
• Frog skin section

  dermis > epidermis

  chromatophores - pigments
• Frog skin section

  mucus gland - smaller, lightly stained

  poison gland - larger, brightly stained
• Human scalp


  hair follicle, hair grows at an angle

  hair - dermal origin
• Human scalp epidermis

  stratum basale/ germinativum - mitotically active

  stratum spinosum - keratinocytes

  stratum granulosum - fibers

  stratum lucidum - transition layer

  stratum corneum - dead cells, sheds
• Human scalp glands

  sebaceous gland - secretes sebum, associated with hair follicles

  sweat gland
• Human scalp

  dermal papilla - gives rise to hair

  arrector pilli - goosebumps
• Human Brown Skin

  purple stained- epidermis

  easier to stain due to melanin (?)
• Human Palm skin

  thicker because it always shed
• Fish scales

  placoid scale

  cycloid scale

  ctenoid scale

  ganoid scale
• Placoid scale


  usually has 3 spines ( lateral and median)

  basal plate- site of direct attachment to the skin of the fish

  sharks
• Cycloid scale

  circular rings representing annular age

  no spine

  lungfish
• Ctenoid scale

  fringe projections

  -ctinii - comb-like teeth

  circulii -annual rings

  ray-finned fishes
• Ganoid scale

  has spine

  covered with enamel-like substance called ganoin

  bowfins and gars
• Bird Feathers

  pterylae - precise tracts in bird skin where feathers are confined
• Bird Feathers

  apteria - areas devoid of feather
• Bird Feathers

  calamus - large hollow shaft, attaches feather directly to the skin
• Bird Feathers

  rachis - central rod
• Bird Feathers

  afterfeather - downy lower barbs of feather
• Bird Feathers

  barb, barbus, barbule, hooklets