Vertebrate Integumentary System, part 2 (Reptiles, Birds, Mammals)

Archosauromorpha

"Ruling reptiles" crocodilians and birds

Epidermal glands in birds

*****uropygial glands (base of tail) are used to oil & preen (absent in woodpeckers, pigeons, parrots & ostriches).

Only 2 cervidae without horns

Chinese water deer and musk deer They both have tusks

5 majors types of feathers

Contour Semiplume Down Filoplume Bristle

feather follicle

Depression in the skin that gives rise to and stabilizes a new feather. Covered in a membrane called periderm.

Dichromatic

Displaying two colors, as in squirrels.

carapace

Dorsal shell of a turtle

Embryologic origin of turtle and lepidosaur scales

Epidermal layer. (*****Fish scales are mesodermal in origin****)

Mammalian epidermal and dermal modifications

Epidermal: Hair, various glands, nails, scales, hooves, baleen Epidermal and dermal: horns

Epidermally, ectoderm

Fish scales are dermally derived, specifically from mesoderm while reptilian scales are _________________ derived, from the ________.

5 functions of feathers

Flight Protect the skin from trauma, rain, excessive radiation from sun Thermoregulation Camouflage Communication behaviors

Structure of claws, hair, nails, hooves

Hard, keratinized, modifications of stratum corneum that are not shed

Modified centrifugal molts

In woodpeckers and treecreepers, begins with the second innermost pair of feathers and finishes with the central pair of feathers so that the bird maintains a functional climbing tail.

Centrifugal molts

Inner most feathers molt first

hair cortex

Middle, thickest portion of a hair shaft

Hair

Non-living, keratinized and replaced seasonally, it is found in ALL mammals at some stage (only found in the young in some whales but is at 100,000 per cm2 in the sea otter).

Melanin

One of the pigments that gives mammalian hair its color

Dermal scales in mammals

Only in the armadillo

bristles

Short, stiff hairs on an animal's skin

5 layers of mammal keratinized stratified squamous epidermis

Stratum Corneum Stratum Lucidum Stratum Granulosum Stratum Spinosum Stratum Basale or Germinativum (Could Love Go So Bad? or Great?)

poisonous feathers - who has them and how?

Three species of pitohuis, endemic to New Guinea, have poisonous feathers via the production of the same steroidal alkaloid Phyllobates forms (hematobrachotoxin - activate sodium channels). The birds get the toxin from beetles that they feed on.

4 types of horns

True horn Rhino horn Giraffe horn Antlers

Speed of feather development

Usually 4-8 weeks, smaller species have faster time Uropygeal glands keep feathers well oiled

Summary of Panda slide

Why do pandas have piebald coloration? Is it aposematic, for camouflage, communication, eye protection, or regulating body heat? Scientists studied patterns of marking in other mammals. No link between temperature and coloration, no link between eye patches and bright sun glare. There was a link between white coloration and camouflage for snow. Panda's dark markings likely help them hide in the forest. Pandas' coloring is a compromise between the two, since they reside in both snowy and forest habitat year round. Eye patches are likely to communicate and to recognize each other. Eye patches are a sign of aggression - they can be widened to scare off enemies and covered to indicate playfulness/non-aggression.

True horn

bony dermal core covered with a permanent epidermal sheath - bovides - cattle, sheep, goats - never shed, do not branch, both sexes

antlers

yearly grown & shed branched dermal bone that sheds velvet at end of growth phase. This yearly cycle occurs only in males in most species (exceptions are caribou & reindeer) and is the result of photoperiod stimulus on the adenohypophysis.

Xanthophyll

yellow pigment that gives mammalian hair yellow/red color, only found in the medulla

Muntjac

common name "barking deer." have bony horns and tusks.

Reptilian dermis - structure and function

consists of fat, nerves, bvs, & chromatophores. Color may serve as protective (camo & warning), reflect social status, sex recognition & thermoregulation. Chameleons may change their color by concentrating & dispersing pigment granules.

baleen

cornified oral epithelium of Mysticeti whales (toothless & strain plankton)

3 types of reptile scales

cycloid granular (appear bumpy) keeled (have a center ridge)

Lepidosauromorpha

lizards, snakes, tuataras

Non-ossified collagenous fiber plates

make up the shells of soft-shell turtles

What causes feather coloration?

melanins, carotenoids, porphyrins within feathers. Metallic hues & iridescence are produced by refraction & refection of light from the barbs & barbules.

scent glands

modified sudoriferous or sebaceous glands. Often used as a pheromone for reproduction or territorial marking (deer use scent from preorbital, tarsal, metatarsal & interdigital glands to communicate). Skunks use perianal glands and N-butyl-mercaptan as a defense mechanism.

Mammary glands

modified sweat gland, hormonally controlled, 1 to 12 pair variously placed: thoracic (bats, primates, elephants), thoracic & abdominal (rodents, carnivores) or inguinal (ungulates). Monotremes (echidna, platypus) lack true mammary glands but a nutritious secretion flows down tufts of hair.

Rhino horn

packed keratinized filaments that differ from hair in that there is no cuticle and possess gaseous spaces

Ecdysis

periodic shedding of the cuticle in arthropods or the outer skin in reptiles

Hooklets

portion of the barbules that need to be preened

7 functions of guard hair

protective tactile insulatory buoyant aposematic concealment communication

Epidermal scales in mammals

rats, beavers (on tails)

3 functions of horns

reproductive behavior offense defense

4 types of modifications of the reptilian integument

scales claws (****not found below the turtle****) rattles (ex: diamondback rattler in TN) horny protuberances (horns of the horned toad)

Hematobrachotoxin

steroidal alkaloid that activates sodium channels. Used by Phyllobates (poison dart frog) and 3 species of pitohuis.

4 types of mammalian glands

sudoriferous sebaceous scent mammary

sudoriferous glands

sweat, for thermoregulation and elimination of waste (urea, salts). Found in most mammals but are absent in moles, anteaters, elephants & some marine forms. In others their distribution is limited to face (bats) or soles of feet (mice, cats).

guard hair

the long hairs that form the protective outer layer of fur

arrector pili

tiny muscle fibers attached to the hair follicles that cause the hair to stand erect

Testudomorpha

turtles

Plastron

ventral part of a turtle's shell

underfur

very dense, soft, short hair that is found beneath the longer, coarser guard hairs

hair medulla

innermost portion of a hair shaft

barbs and barbules

interlocking hooks, make the feathers sturdy but flexible

How do owl feathers allow for near-silent flight?

1. Serrated leading edge reduces noise at high speeds 2. Flexible fringe on the trailing edge of the wing 3. Downy feathers on wings and tail absorb the remainder of the sound

quills

A collection of sharp, hollow spines on the back of a porcupine. Barbed on the end.

Photoperiodism

A physiological response to photoperiod, the relative lengths of night and day. Animals often change behaviors based on the amount of light. Examples for mammal integument: ermine, hare change colors in winter

Pterylae

Feathers run in several different tracts and overlap each other to give that fully-feathered look. Birds that lack pterylae are ostriches & penguins.

Centripetal molt

Outermost feathers molt first, seen in Phasianidae (pheasants, etc.)

Molting

The process of feather replacement. Usually only a few at a time In raptors, once per year beginning in April, completed by September Stimulated by environmental conditions

Why do these bird have red eyes?

The toxins most likely come from the beetle genus Choresine, part of the birds' diets.

Vibrissae

The whiskers, which have a sensory function (mystacial - moustache region; superciliary - eyebrow region)

Squamata

______________ (snakes and lizards) go through ecdysis

Mammalian melanoctyes

abundant pigmentation cells

Giraffe horn

also Okapi, stunted horns that never shed and retain velvet

adenohypophysis

anterior lobe of the pituitary gland

Silent flight in owls - how and why?

elongated downy extensions of barbules and hairlike fringes along flight feathers. To scare the living pants off someone.

Reptile integument

epidermal origin functions: protection, locomotion (in snakes) Very few glands (musk, femoral, pre-anal, cloacal...specific and sex recognition) No sweat glands

Integumentary feature of pangolins

epidermal scales

Contour feathers

feathers responsible for flight (wing and tail feathers)

Blood feathers

growing feather with a vascular shaft (after growth is completed, the feather dries up and is no longer a living structure) also called pin feathers

sebaceous glands

oil is emptied into the hair follicle for lubrication and as an antibacterial

Brood patch

on the abdomen of birds, a thickened, featherless patch of skin that is used for incubating eggs

alpha keratin

or α-keratin, is a type of keratin found in vertebrates. This protein is the primary component in hairs, horns, mammalian claws, nails and the epidermis layer of the skin. α-keratin is a fibrous structural protein, meaning it is made up of amino acids that form a repeating secondary structure. The secondary structure of α-keratin is very similar to that of a traditional protein α-helix and forms a coiled coil.[1] Due to its tightly wound structure, it can function as one of the strongest biological materials and has various uses in mammals, from predatory claws to hair for warmth. α-keratin is synthesized through protein biosynthesis, utilizing transcription and translation, but as the cell matures and is full of α-keratin, it dies, creating a strong non-vascular unit of keratinized tissue.[2] (wikipedia.com)