Integumentary System Flashcards by Miyaki Jan Lim

primary role of the integument

protection

How well did you know this?

Not at all

Perfectly

protects the internal organs from mechanical injury

Dermal armors

How well did you know this?

Not at all

Perfectly

secrete slimy or noxious substances

Glands

How well did you know this?

Not at all

Perfectly

provide protective coloration

Serves as barrier to the rays of the sun

Pigments

How well did you know this?

Not at all

Perfectly

Exteroceptive Role of the integument

Protective in its most primitive state

Naked nerve endings are stimulated when foreign objects contact the skin
The only role of cutaneous receptors in agnathans

More complex receptors are found in other fishes and tetrapods and highly used for survival

How well did you know this?

Not at all

Perfectly

Some Roles of the Integument

Protective Role
Exteroceptive Role of the integument
Respiration
Excretion
Thermoregulation
Locomotion
Maintenance of Homeostasis
Nourishment
Pheromones
Skin Coloration

How well did you know this?

Not at all

Perfectly

Roles of the Integument
Naked nerve endings are stimulated when foreign objects contact the skin
The only role of cutaneous receptors in agnathans

More complex receptors are found in other fishes and tetrapods and highly used for survival

Exteroceptive Role of the integument

How well did you know this?

Not at all

Perfectly

Roles of the Integument
Supplements gills and lungs of many amphibians (aquatic urodeles)

Respiration

How well did you know this?

Not at all

Perfectly

Scales and cornified epithelium are not conducive for cutaneous respiration

true

How well did you know this?

Not at all

Perfectly

_____________ rely its respiration entirely on the skin (they don’t have gills or lungs)

Plethodontid salamander

How well did you know this?

Not at all

Perfectly

Roles of the Integument
CO2 excretion in some aquatic amphibians

Sweat glands are supplementary to excrete nitrogenous wastes

Ammonia in fishes is easily diffused via gill epithelium and other tissues exposed to water

Excretion

How well did you know this?

Not at all

Perfectly

Roles of the Integument
Function of the skin of endotherms (birds and mammals)

Fur and feather insulate against cold

Sweat cools by evaporation

Thermoregulation

How well did you know this?

Not at all

Perfectly

Dilation of blood vessels within the dermis heat loss by radiation

increases

How well did you know this?

Not at all

Perfectly

Roles of the Integument
Performed by adhesive pads, claws that assist in climbing, scutes that assist in slithering and feathers that provide airfoil

Webbed feet for those that wade in water

Webbed wings in bats enable them to fly

Locomotion

How well did you know this?

Not at all

Perfectly

Roles of the Integument
Reservoirs of calcium and phosphate molecules in fishes

Cornified epithelium of tetrapods conserve water

Absorbs water under the influence of posterior pituitary gland in aestivating lungfishes, toads and other craniates

Maintenance of Homeostasis

How well did you know this?

Not at all

Perfectly

Roles of the Integument
Mucus secreted in some teleosts provide nutrition to hatchlings

Mammary glands provide nourishment to the young

Maintenance of Homeostasis

How well did you know this?

Not at all

Perfectly

Roles of the Integument
Serves as species identification or serves as alarm

Elaborate colorations help during breeding season

Can be used as protection

Pheromones and Skin Coloration

How well did you know this?

Not at all

Perfectly

Forms the interface between the animal’s internal environment and the outside world

Integument

How well did you know this?

Not at all

Perfectly

Contains epithelial, connective adipose and smooth muscle tissues

Also contains blood vessels, glands, sensory receptors, nerves and other structures

Integument

How well did you know this?

Not at all

Perfectly

Superficial part of skin; stratified squamous epithelium; composed of four or five strata

Barrier that prevents water loss and the entry of chemicals and microorganisms; protects against abrasion and ultraviolet light; produces vitamin D; gives rise to hair, nails, and glands

Epidermis

How well did you know this?

Not at all

Perfectly

Most superficial strata of the epidermis; 25 or more layers of dead squamous cells

Provision of structural strength by keratin and protein
envelope within cells; prevention of water loss by lipids surrounding cells; sloughing off of most superficial cells resists abrasion

Stratum corneum

How well did you know this?

Not at all

Perfectly

Three to five layers of dead cells; appears transparent; present in thick skin, absent in most thin skin

Dispersion of keratohyalin around keratin fibers

Stratum lucidum

How well did you know this?

Not at all

Perfectly

Two to five layers of flattened, diamond-shaped cells

Production of keratohyalin granules; lamellar bodies release lipids from cells; cells die

Stratum granulosum

How well did you know this?

Not at all

Perfectly

A total of 8 to 10 layers of many-sided cells

Production of keratin fibers; formation of lamellar bodies

Stratum spinosum

How well did you know this?

Not at all

Perfectly

Deepest strata of the epidermis; single layer of cuboidal or columnar cells; basement membrane of the epidermis attaches to the dermis Production of cells of the most superficial strata; melanocytes produce and contribute melanin, which protects against ultraviolet light

Stratum basale

Deep part of skin; connective tissue composed of two layers Responsible for the structural strength and flexibility of the skin; the epidermis exchanges gases, nutrients, and waste products with blood vessels in the _______

Dermis

Papillae project toward the epidermis; loose connective tissue Brings blood vessels close to the epidermis; dermal papillae form fingerprints and footprints

Papillary layer

Not part of the skin; loose connective tissue with abundant fat deposits Attaches the dermis to underlying structures; fat tissue provides energy storage, insulation, and padding: blood vessels and nerves from the subcutaneous tissue supply the dermis

Subcutaneous tissue

Composed of a stratified epithelium which developed from embryonic ectoderm

Epidermis

consists of 1 to 2 mitotically active, cuboidal cell layers located above the basement membrane Cells move toward the body surface to differentiate and are eventually sloughed off

Stratum germinativum

Mat of collagen and elastin fibers; dense irregular connective tissue Main fibrous layer of the dermis; strong in many directions; forms cleavage lines

Reticular layer

Composed of a stratified epithelium which developed from embryonic ectoderm

Epidermis

Some epidermal cells synthesize _________ which is a water-insoluble, horny protein that may fill the cells and replace other organelles

kertain

animals that have a thin layer of epidermis

Fishes and amphibians

Epidermis Two types of covering:

Aquatic craniates - Terrestrial craniates - water-impervious cornified cells

animals that have a thick layer of epidermis

Reptiles and mammals

which is a water-insoluble, horny protein that may fill the cells and replace other organelles

stratum corneum

Epidermis covering that has a thin coat of mucus

Aquatic craniates

Epidermis covering that is mostly multicellular

Terrestrial craniates

Develops from mesenchymal cells which are mostly derived from mesodermal dermatome of somites

Dermis

Basic component is collagen and elastic fibers embedded in proteoglycans and other macromolecules which holds other component in place and provide tensile strength

Dermis

Other components of dermis

blood vessels, small nerves and pigment cells Lymphatics Naked and encapsulated exteroceptors Bases of multicellular glands Bases of hairs or feathers and their erector muscles

is thicker than the epidermis in mature skin and consists of two layers: Irregularly arranged collagen fibers

Dermis

Dermis consists of two layers:

Stratum laxum Stratum compactum

Teeth, bony and horny scales, feathers and hair develop as a result of intricate interactions between the dermis and epidermis via neural crest cell migration

Skin Derivatives

Glands, feathers, hair and other keratinized structures are composed of __________ in which some parts invade the underlying dermis

epidermal cells

Superficial bones are dermal derivatives

true

Teeth and bony scales are of ______ and _____

epidermal and dermal products

These structures have supportive and protective functions that they are sometimes termed as

integumentary skeleton

Cells that contain pigments found in all vertebrates except albinos Develop from neural crests and are located in the upper part of the dermis in fishes, amphibians and reptiles They penetrate and are located in the epidermis of birds and mammals

Chromatophores

Star-shaped cells containing melanin With long, branching processes granules may either be black, brown or more yellow and reddish

Melanophores

Melanophores contained within cellular organelles called

melanosomes

is synthesized within melanophores of birds and mammals but most of it is transferred to feather, hair and other epidermal derivatives

Melanin

in anamniotes and reptiles may migrate into processes of the melanophores, maximizing the color or concentrating it

Melanosomes

Contain crystalline chemochromes from guanine Generate iridescent colors because of the diffraction of light within the stacked plates

Iridophores or guanophores

Utilize crystalline purines (often guanine) to reflect light Produce reflective white hues

Leucophores

Contain yellow pigments composed of pteridines

Xanthophores

Contain reddish pigments composed of carotenoids

Erythrophores

Vesicles containing pteridine and carotenoids are sometimes found in the same cell

true

Unique copper uroporphyrin pigment responsible for the bright green coloration of several birds of the family Musophagidae, most notably the turaco The only true green pigments found in birds

Turacoverdin

Naturally occurring red pigment Found only in the bird family Musophagidae, the turacos

Turacin

Important Roles of Skin Coloration

Can be concealing or cryptic helping an animal hide from predators or enable a predator to stalk a prey Can be aposematic where it advertises the presence of dangerous, venomous or distasteful species Also used for species recognition, establishment of territories, courtship and other types of communication Also help reptiles thermoregulate

is similar in its basic structure Epidermis is relatively thin and most cells are alive Surface cells are covered with microridges that increase the surface area for exchange between the animal and its environment

Fish Integument

may be deposited in limited areas such as horny teeth of cyclostomes and tubercles that develop in many fishes during mating season

Keratin

secrete only mucus in fish

Goblet cells

secrete mucus and additional ingredients mostly of unknown functions in fish

Granular cells

_________ which are products of granular cells are not common in fish

Alkaloids

glads that are not abundant in fish

Multicellular glands

_______ can be for protection, for nutrition and some contain toxins

Slimy mucus

in fish, Light-emitting organs in deep-sea teleosts Upper part of the gland consists of modified mucous cells acting as magnifying lens Beneath the lens are light-emitting cells Cells below are in contact with melanophores and in blood cells which is the source of raw materials The light is not intense and usually of many hues

Photophores

light from Photophores components

Luciferase + luciferin =

Functions for Photophores

Species and sex identification Lure for prey in carnivores or is a warning that it is a carnivore Concealment by countershading

Highly mitotic, multi-layered epidermis with unicellular mucous glands No keratinized or cornified layer Horny denticles on buccal funnel or teeth are the only keratinized structures

Epidermis of Agnathans

Multi-layered than agnathans Not as much unicellular glands except in chimeras Localized glands include: Goblet cells Multicellular glands Photophores in the dermis are modified epidermal glands that lost connection with the epidermis

Epidermis of Cartilaginous Fishes

Collagen fibers are generally more regularly arranged than of other vertebrates Develop in layers that spiral around the body in approximately 45o angle to the longitudinal axis with adjacent layers perpendicular to each other Fiber arrangement strengthens the skin so that body shape is maintained during swimming

dermis of Cartilaginous Fishes

dermis acts as ___________ transmitting muscular force in sharks

exotendon

Bony Dermis of Fishes Generalized pattern:

4 = enamel or enamel-like substance 3 = dentin (denticles is 3 + 4) 2 = vascular spongy bone 1 = lamellar bone

Dermal Scales

Placoid Rhomboid Cosmoid Ganoid Elasmoid Ctenoid Cycloid

Dermal Scales Elasmobranchs

Placoid

Dermal Scales Dentine crown with a pulp cavity and covered by enameloid/enamel (ameloginin proteins)

Placoid

Dermal Scales Osteichthyans

Rhomboid

Dermal Scales Fossil sarcopterygians

Cosmoid

Dermal Scales Layer 4 is composed of ganoine, a form of ename

Ganoid

Dermal Scales Specialized canal system associated with dentine and enamel, not a tissue but a structural complex

Cosmoid

Dermal Scales Actinopterygians

Ganoid

Dermal Scales Teleosts

Elasmoid Ctenoid Cycloid

Dermal Scales Thin lamellar bone that may be associated with a fibrous plate

Elasmoid

Dermal Scales Possesses small spines (ctenii), a derived scale

Ctenoid

Dermal Scales Composite group of ctenoid-like scales lacking spines

Cycloid

No dermal bone Thinner than epidermis Tough due to collagen connective tissue With many melanophores With slime glands

Dermis of Agnathans

No dermal bone Surface denticles (placoid scales) present except in chimeras Thicker than the epidermis With melanophores (more dorsally)

Dermis of Cartilaginous Fishes

Cosmoid and ganoid in basal actinopterygians and neopterygians (Polypterus and garpikes) Cycloid and ctenoid in modern fishes

Dermis of Bony Fishes

relatively thin but epidermal cells synthesize keratin As it accumulates, cells die and the stratum corneum is formed which is seldom more than 1 to 2 layers thick to allow cutaneous respiration Desquamated periodically and is hormonally controlled Not sloughed off in toads and they just continually pile up Desquamated periodically and is hormonally controlled Not sloughed off in toads and they just continually pile up Highly glandular Glandular glands aid in survival of land-adapted anurans Transitional between those that spend more time and more on land Cornified appendages are rare

Amphibian Epidermis

loss of bits of outer skin by peeling or shedding or coming off in scales

Desquamated

Amphibian Epidermal Glands

Mostly multicellular mucous or granular glands

In Amphibianw, _____ on digits serves as holdfasts in trees or glands on thumbpads during breeding season serves as restraint for females

Glands

___________ amphibians have the most number of multicellular glands Secretions keep the skin moist when they are on land

Tailed aquatic

Present in toads Secrete irritating alkaloids which are defensive in nature or pheromones used during breeding Restricted to a localized area of the body

Granular Glands

Keratin in amphibians is shown by

Aquatic urodeles have thin desiccation-impending stratum of cornified cells Anurans tadpoles have horny tooth like structures which is shed during metamorphosis

Firmly attached to underlying muscles in apodans and urodeles Anurans have lymph sinuses separating it from muscles Dermal chromatophores in other species can elicit color change Bony scales (osteoderms) present in head of caecilians and a few tropical toads at the back

Dermis in amphibians

Represents the ultimate adaptation of craniate skin for surviving in an arid and hostile environment With many localized modifications: horny scales, scutes, beaks, rattles, claws, plaques and spiny crests found on the stratum corneum Granular glands are found in some region only

Reptile Epidermis

Repetitious thickenings only found in amniotes Disposed on overlapping folds of the epidermis in squamates where thinning at scale joints allow for movement Scutes are large, thin, polygonal scales

Epidermal Scales

the dermis of Reptiles has dermal bone

true

the dermal bone of turtles

carapace, plastron and lateral bridges

Soft-shelled and leatherback turtles lack

dermal ossification

the dermal bone of Crocodiles and some lizards

osteoderms in localized regions of the body (gastralia in ventrolateral abdominal wall)

the dermal bone of snakes

absent

Scales only present at the feet and base of the beak Claws are present on the toes and one or two on digits of the wings

Avian Epidermis

Glands are generally lacking in avians except:

Uropygial glands Oil glands

glands at the tail base for preening

Uropygial

glands at outer ear canal of domesticated birds

Oil glands

Prominent swelling at the rump behind the pygostyle Largest in aquatic birds and in domestic fowl Oil which is water-repellent is used for preening

Uropygial gland

are found in outer ear canal and sometimes in the vent area

Smaller oil glands

Feather types

down feather contour feather filoplume

Development of a Feather

Dermal Papilla is formed Feather Primordium is induced DP becomes vascularized or Feather Follicle develops as FP elongates from Feather Primordium, Growth Zone develops at the base of the FF giving rise to the feather sheath FS splits open as the shaft elongates to full growth from feather sheath DP dies when the feather is fully grown and becomes pulp as the Inferior Umbilicus is formed

Supports feather follicles and erector, depressor, retractor and rotator muscles

Dermis of birds

are cornified appendages first developed for insulation and is a modified scale

Feathers

No osteoderms in birds except for ___________

gamecocks

Stratum germinativum - basal layer Stratum granulosum - with keratohyaline Stratum corneum - highly keratinized Give rise to scales (armadillos and pangolins), claws (hoofs and flat nails) and horns Thickest on parts of appendages in contact with surfaces (palms, hooves, feet) Stratum lucidum - present in palm and sole

Mammalian Epidermis

Hair are _________ includes horns, pronghorn, antlers, baleen of whales and epidermal scales

cornified epidermal appendages

________ are present in most mammals and can be modified as nails in primates or hooves in ungulates

Claws

Epidermal Glands based on Structure

Tubular -Simple -Branched -Coiled -Compound Alveolar -Simple -Branched -Compound

Epidermal Glands based on Substance secreted

Mucous Granular Avian oil Sebaceous Sweat Scent Mammary

Epidermal Glands based on Mode of elaboration

Merocrine Apocrine Holocrine

Cells of the gland produce secretions by active transport or produce vesicles that contain secretory products, and the vesicles empty their contents into the duct through exocytosis.

Merocrine gland

secretory products are stored in the cell near the lumen of the duct. A portion of the cell near the lumen containing secretory products is pinched off the cell and joins secretions produced by a merocine process.

Apocrine gland

Secretory products are stored in the cells of the gland. Entire cells are shed by the gland and become part of the secretion. The lost cells are replaced by other cells deeper in the gland.

Holocrine gland

Generally absent in tetrapods except in mammals Lost survival value when skin became covered with cornified cells Synthesis of mucus will dehydrate craniates that don’t have continuous access to water

Mucous Glands

Present when there are hairs and sebum is exuded into hair follicles

Sebaceous Glands

Present when there are hairs and sebum is exuded into hair follicles

Ceruminous glands

glands that assist in lubrication of conjunctiva of the eye

Meibomian glands

Sebaceous Glands of mammals

Meibomian glands

which is an inflamed swelling on the conjunctival surface of the lid is caused by ducts of the Meibomian glands being occluded

Chalazion

Other sebaceous glands open independent of hair:

Lips Glans penis Labia minora Areola

Sudoriferous or Sweat Glands in Furry animals

feet of cat and mice, lips of rabbits and side of head of bats

Sudoriferous or Sweat Glands in pangolins, sirenians, cetaceans and echidnas

Absent

Sudoriferous or Sweat Glands in Hippopotamus

only on the ears

example of Sudoriferous or Sweat Glands

Ciliary glands is one example

Scent Glands

anal gland tarsal gland temporal gland

Compound alveolar glands that develop in both sexes along the milk line Number and location (axillary, thoracic, abdominal and inguinal) is dependent on the animal species

Mammary Glands

hormone responsible for milk-let down

Oxytocin

hormone responsible for milk production

prolactin

Very thick - hair follicles, erector muscle, numerous glands, connective tissue, vascular tissue, nervous tissue

Dermis of mammals

examples of dermal bones

Dermal bones of armadillos Antlers and giraffe horns

separates the dermis from underlying muscles in mammals

Superficial fascia

is a type of contour-shaping adipose tissue found in cetaceans to replace hair

Blubber

bony structure derived from intramembranous ossification forming components of the vertebrate skeleton, including much of the skull, jaws, gill covers, shoulder girdle, fin rays, and the shells of turtles and armadillos.

dermal bone or investing bone or membrane bone