Integument

1
Integument
2
Function

• Support and Protection
• Reception and Transduction of Signals and Stimuli
• Transport
• Heat regulation
• Respiration
• Water Balance
• Nutrient Storage
• Behavior
• Coloration
• Etc

3
Basic Structure

• Epidermis
• Ectoderm
• Dermis
• Dermatome, Neural Crest, Somatic Mesoderm
  (Somatopleure)
• basement membrane

4
Epidermis

• Epidermis--several layers.
• Stratum germinativum (stratum basale)-- deepest
  layer.
• Layers superficial to stratum germinativum-- two
  general categories
• Mucous cells (mucus, poisons).
• Proteinaceous cells (slime, poisons, enamel,
  keratin).

5
Dermis

• Dermis.
• Characterized by meshwork of fibers
• Collaginous fibers.
• Elastic fibers.
• Usually an outer vascular stratum spongiosum
  (stratum laxum) and a deeper, thicker stratum
  compactum.

6
Basic Structure
7
Embryonic Origin

• Ectoderm
• Neural Crest (ectomesenchyme)
• Mesoderm

8
Development
9
Derivatives

• Epidermal
• Epidermal-Ectomesenchymal
• Mesodermal

10
Coloration

• Differential Scattering
• Scales
• Feathers
• Pigment
• Melanophores
• Dark colors
• Iridophores
• Light reflecting colors
• Erythorphores
• Red
• In non-mammals, generally Dermal
• In mammals pigment is transferred to epidermal
• Allows for hair, feather colors

11
(No Transcript)
12
Ectoderm and Mesoderm work together in specifying
integument structures
13
Amphioxus Integument

• Single Cell layer epidermis
• Unicellular glands
• Structure from Dermis

14
Phylogeny of Skin

• Lamprey
• Epidermis thin.
• Several types of glands
• Largely single cell glands (indicative of fishes)
• mucous glands
• club glands, granular glands).
• Limited Keratin
• Tongue teeth.
• Mucous Cuticle.
• Dermis thin.
• No scales

15
Fish

• Single cells glands
• Club cells
• Mucous glands
• Some multicellular glands
• Photophores-light emitting glands
• Slime glands in hagfish
• Dermal Scales
• Structural integrity comes from dermis
• Epidermis thin with mucous cuticle
• Unicellular gland, some granular glands secreting
  pheromomes or toxins.

16
Fish Scales

• Placoid-Sharks
• Likely derived from primitive bony scales
• Dermal-Dentin
• Epidermal-Enamal
• Cosmoid-Lobed-fin fish
• Dermal-Dentin, bone (vascular and lamellar)
• Epidermal-Enamel
• Ganiod-Ray-fin fish
• Dermal-Dentin, bone (lamella, reduced vascular)
• Epidermal-Ganoinenamel
• Present in primitive ray-fin fish
• Teleost Scale-most modern fish
• Lamelar bone only
• No dentin or enamel
• Ctenoid and Cycloid

17
(No Transcript)
18
(No Transcript)