Chapter 4 Flashcards
what is one of the largest organs of the body?
the vertebrate integument
what are 8 exasmples of what epidermis forms?
- hair
- feathers
- baleen
- claws
- nails
- horns
- beaks
- some scales
the superficial layers in contact with the outside environments is the ——–, below it is the —— and between them is the ——- ———
epidermis/dermis/basement membrane
epidermies derives from what?
dermis derives from what?
epidermis=ectoderm
dermis=mesoderm and mesenchyme
plies:
collagen fibers woven into distinct layers
mucus seems to afford some protection from what?
bacterial infection and helps ensure the laminar flow of water across the surface.
in terrestrial vertebrates the epidermis covering the body often forms an outer keratinized layer called what?
stratum corneum
where dermal contributions predominate, especially in the form of ossified dermal bone, the fold is termed what?
a dermal scale.
epidermal scale:
where the epidermal contribution predominates, especially in the form of a thickened keratinized layer.
what are the 4 scales?
- Placoid scale
- Cosmoid scale
- Ganoid scale
- Cycloid-ctenoid scale
do fish have a keratinized surface?
no
what allows the skin of a fish to bend without wrinkling?
collagen within the dermis
do fish have dermal or epidermal scales?
dermal
unicellular glands include what 2 cells?
- club cells
2 granular cells
in chondrichthyes or cartilaginous fishes, what is absent and what scales do they have?
dermal bone is absent and placoid scales persist
in bony fishes do dermal scales peirce the epidermis?
no