INTEGUMENT

INTEGUMENT - FORM VS FUNCTION IN THE VERTEBRATES

PHYSICAL BARRIER - allows HOMEOSTASIS

MECHANICAL PROTECTION

stress, abrasion, puncture

CONFLICT - protection vs flexibility

PERMEABILITY - ADJUSTABLE

ion and water balance

gas exchange

varies with environment - aquatic vs terrestrial

THERMOREGULATION

control blood flow - heat loss/gain

sweat

insulation

SIGNALLING/DEFENCE

pigments - cryptic/warning for predators

secretions - pheromones/toxins

SENSORY

mechanoreception

thermoreception

INTEGUMENT IN FISHES

-no keratinized outer layer

-mucus - protection

-scales

CVH slide 100 lamprey skin

LAMPREY EPIDERMIS CVH100

mucus cell club cell

granule cell

DOGFISH EPIDERMIS CVH 77

mucus cell club cell

TELEOST EPIDERMIS CVH 155

CVH slide 100 lamprey skin - melanocytes in dermis

DOGFISH SKIN CVH 77

mucus cell club cell

melanocytes in dermis

DOGFISH DERMAL LAYERS CVH 77

stratum

spongiosum

stratum

compactum

LAMPREY EPIDERMIS CVH100 - no stratum spongiosum

mucus cell club cell

granule cell

stratum compactum

FISH SCALES: in dermis

elasmobranchs - placoid scales

same structure as teeth - dentin core,

enamel outer layer

teleosts - bony scales

DOGFISH: DEVELOPING PLACOID SCALES CVH 61

odontoblasts making enamel

HEAD OF DEVELOPING DOGFISH sagittal section CVH 61

mouth

LOWER JAW WITH DEVELOPING DERMAL DENTICLES

CVH 61

UNERUPTED DERMAL DENTICLE CVH 61

TELEOST DERMAL SCALES CVH 155

scale

TIP OF DERMAL SCALE - epidermis folded over edge

CVH155

BASE OF SCALE (*) ANCHORED IN DERMIS CVH 155

*

INTEGUMENT IN AMPHIBIANS

-in transition to terrestrial living

(still spawn in water)

-aquatic or partly aquatic forms

- mucus skin covering

-first vertebrate keratinization

Ambystoma - semi-aquatic salamander

mucus layer

Sheldon, amphibiainfo.com

FROG SKIN - GLANDS IN DERMIS (CVH32)

FROG SKIN - GLANDS IN DERMIS (CVH32)

STRATUM

CORNEUM

IN TOAD

LEG SKIN

CVH 164

DERMAL CHROMATOPHORES

melanocytes - brown/black pigment granules

xanthophores - yellow oil droplets

erythrophores - red oil droplets

iridophores - protein plates - reflect light - silvery

DEFENSIVE

COLORATION

IN AMPHIBIANS

INTEGUMENT IN REPTILES

-fully terrestrial (lay eggs)

-scales - modified stratum corneum

-ecdysis (molting)

continuous - crocodilians, turtles

periodic - lizards, snakes

outer scale inner scale

SNAKE INTEGUMENT CVH 108

hinge region

SNAKE INTEGUMENT CVH 108

INTEGUMENT IN BIRDS

-keratinized structures derived from

epidermis

feathers

beak

scales

-dermis - thin, anchors feathers

BIRD SKIN BETWEEN FEATHER FOLLICLES CVH 112

FEATHER FOLLICLES (F) IN BIRD SKIN (CVH112)

F epidermis

dermis

MAMMALIAN INTEGUMENT

-structure similar to human

MAMMALIAN INTEGUMENT

-structure similar to human

-epidermally derived specialized structures - keratinized

fur/wool/hair

horns, antlers, hooves, claws

scales - rodent, opossums

shells - armadillo - keratin plates over dermal bone

baleen plates - filters for krill feeders

BALEEN FILTER IN MOUTH OF BLUE WHALE

alumniexhibits.com