Flashcards in Vertebrates 5c - Integument of the rest Deck (47)
Glandular (granular, mucous), no scales, thin protective layer (stratum corneum)
Granular gland in amphibian
Some make antimicrobials, toxins (like parotid),
Mucous in amphibians
Help keep skin moist, traps bacteria and parasites
Thick stratum corneum; epidermal keratin plates/scales; only from epidermis; no mucous glands
Layers of reptilian epidermis
Outer epidermal generation, fission zone, inner epidermal generation, stratum germinativum (stem cells), then dermis.
Problem with reptilian skin?
Very thick and dead, can’t expand. Must shed of molt. Fission zone becomes active and it molts. The living cells below keratinize and die before molting.
Made of keratin. Used for grasping, digging. Hunting (raptors)
Scales of keratin on feet, claws/talons. Similar to reptiles.
An outgrowth, interaction of epidermis and dermis to leave dead cells with lots of keratin. Similar to hair formation.
Vane and Rachis
The fan or surface area and The central shaft
Barbs and barbules
Barbs perpendicular the rachis, barbules perpendicular to barbs
On the barbules. Hold the vane together, Can separate and reattach (preening)
Most of the feathers on the outside of the bird. Different types.
Some of the longest feathers; rachis is to one side of the feather (asymmetrical). Primary on outer wing, secondary inner. Coverts on the front edge of wings
Not as organized, no hooklets. Underneath contour feathers, insulate
Found in some birds around the eyes to protect them. Longer rachis (relatively)
Main roles of feathers
Flight/locomotion, and insulation.
Muscles and feathers
All contour feathers have arrector pili attached. Used to fluff up and insulate, and to rotate to help in flight.
Evolution of feathers
Proto-feathers about 200mya. Shape with just rachis, barbs but not barbules, etc. True feathers and Flight came around 150mya
Some may have had many true feathers. (like Yutyrannus huali).
What needed for flight?
Feathers, light, need wings
First wing/bird. Has feathers and wings, but still had teeth. Might not have flown very well (shorter wings)
Has longer wings but…….
Forms over the bone in lower and upper jaw. Made of keratin. Makes head lighter, replaced teeth. The beak has evolved for certain feeding methods/diets
Beak strains algae and invert. Filter feeding.
aka preening gland, common in ducks, geese. Secretes waxy substance. Bird preens to spread this.
Stratum corneum thickness varies b/w animals and areas of same animal.
Mammalian synapomorphy. Follicle is alive, but hair itself is dead cells. Keratin. Formed from interaction b/w dermis and epidermis.
Guard hairs and underhair. Most animals have this