Integument

Integument

1. Aquatic Vertibrates

   • Mucus Glands
     • secrete mucus to keep skin moist
   • Granular glands
     • in Amphibians secretes toxin

2. Tetrapod Glands

   • Mucus
     • absent from most
   • Granular
     • Amphibians secretes toxins
   • Pheromones
     • affect behavior of other individuals
   • Mammalian
     • Sebaceous
       • produce sebum
     • Circuminous
       • cerumen (earwax)
     • Suderiferous
       • Sweat  thermoregulation
     • Scent
       • sebaceous and sudoriferous pheromones defensive
     • Mammillary
       • compound alveolar # related to # off offspring produces milk high in lipids

3. Epidermis

   • Multilayered and contains glands
   • Nonliving
     • Mucus cuticle
       • moisture anti-bacterial defense
     • Stratum Corneum
       • layer of dead cornified cells retain moisture prevent dessication terrestrial verts
       • Epidermal Scales
         • thinkening of S corneum. protection, resist wear
         • Squamates
           • overlapping with joints
         • Turtles
           • scutes 2 parts 1. carapace = dorsal 2. plastron = ventral
         • Birds
           • localized
         • Mammals
           • rare beaver tails and armadillo
       • Claws, Nails and Hooves
       • Feathers
         • rachis calamus vane composed of barbs 1. plumulaceous 2. pennaceous Only occur in on pterylae
         • Contour
           • body flight
         • Bristle
           • tactile receptors near beak
         • Filoplume
           • air receptor on wings
         • Down
           • no rachis insulation
         • Semiplume
           • rachis but plumalacious insulation and mate attraction
       • Hair
         • develop from follicle pelage arrector pilli
         • Guard Hair
           • protection and create color patterns
         • Underhair
           • tightly packed for insulation
       • Horns
         • made of keratin from epidermis
         • Bovine
           • sheath of keratin covering dermal bone never shed
         • Pronghorn
           • branched and sheath sheds
         • Hair
           • mass of keratin fibers sits on nasal bone

4. Dermis

   • connective tissue blood vessels and nerves metric of collagen fibers thick mineral deposition dermal bone formation
   • Antlers
     • dermal bone shed and replaced anually
     • Velvet integument
       • from epidermis and dermis
   • Chromatophores
     • pigment cells
   • Dermal Bone
     • Ostracoderms and Placoderms
       • plates composed of 1. compact bone 2. spongy bone 3. dentin 4. enamel
     • Tetrapods
       • compact bone Osteoderms Amphibs(Caecilians) Crocodiles
       • Turtles
         • Dermal plates under Skutes fuse to ribs and vertebrae
     • Birds
       • mostly absent
     • Mammals
       • rare dermal armor in armadillo
   • Scales
     • Placoid
       • denticle
     • Cosmoid
       • cosmine layer under enamel in extinct Sarcopterygii
     • Ganoid
       • lacks dentin Ganoin primitive Actinopterygii
     • Elasmoid
       • thin layers of compact bone thin and flexible
       • Cycloid
         • smooth trout and salmon
       • Ctenoid
         • teethlike projections Sarcopterygii and Actinopterygii

5. Avian Glands

   • Uropygial
     • waterproofing prominent in waterfowl

6. Ossicones

   • On Giraffes bone core develops separate from skull covered with skin fighting and poss. thermo regulation