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BIO 305 - A&P of Vertebrates > The Integument > Flashcards

Flashcards in The Integument Deck (33)
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1
Q

What is the general structure of skin?

A

Two main layers: epidermis and dermis

2
Q

What is the epidermis divided into?

A

Stratum corneum (outermost) - thickness varies greatly, usually dead keratanized cells

Stratum germinatuvum - mitotically active

3
Q

What is the dermis divided into?

A
Stratum laxum 
Stratum compactum (innermost)
4
Q

What is keratin?

A

A family of fibrous structural proteins, mostly in tetrapods
Fish have keratin and other similar proteins but not in high numbers
It is important in the structure of hair, feathers, and scales

5
Q

What are the functions of the skin?

A

Physical protection, water balance, thermoregulation, locomotion, gas exchange, coloration, secretion, sensory structure

6
Q

How is the skin important for thermoregulation?

A

Sweat glands
Arrector pilli muscles - attach to hair and feathers
When it contracts, it raises the hair, doesn’t do anything for us. Important for mammals because it allows hot air to be trapped so it acts like an insulating layer.
Seals and sea otters have hair but no pill, makes them slow down in water with pilli

7
Q

How is the skin specialized for sensory structures?

A

COME BACK TO THIS

8
Q

How does skin coloration work?

A

Chromatophores, which are pigment-producing cells that deposit pigment into other cells. Big cells with projections.
In birds and mammals, at the base of the epidermis
In other vertebrates, in dermis

9
Q

What are the different types of chromatophores?

A

Melanophores - brown/black
Iridiophores - shiny (guanine crystals - byproduct of nucleic acid)
Xanthophores - yellow (modified nucleotide)
Erythrophores - red/orange - derivative of B-kerotene

10
Q

What can affect colour? Give an example.

A

Diet in flamingoes

The more B-kerotene they eat, the more pink they look

11
Q

What is another way of colorization?

A

Structural coloration (other = pigment)

12
Q

How does structural coloration work?

A

Cells and proteins are arranged in certain ways that refract light to produce colours
This type of coloration might have been around at the time of the dinosaurs

13
Q

Give an example of a mammal with structural coloration?

A

Mandrill - collagen arranged in certain way

14
Q

How are mammals typically coloured?

A

Mostly only have melanophores which can produce a few different colors

15
Q

How does mammalian coloration work?

A

MSH can stimulated melanophores to produce eumelanin pigment (brown). The pigment is produced in melanosomes (vesicles).

If the MSH receptor is inactivated, it triggers the production of pheomelanin (yellow).

16
Q

What can mutations in MSH receptor lead to?

A

Kermode (spirit) bear - species of black bear that have mutations in the receptor
This is not the same as albino because albino don’t have the pigment, kermode have mutation in receptor

17
Q

What is a cell that produces melanin?

A

Melanophore/melanocyte

18
Q

What is melanin?

A

A pigment molecules that absorbs and reflects light

19
Q

What is MSH?

A

Melanocyte stimulating hormone affects receptors

20
Q

What is an MSH receptor?

A

Melanocortin receptor that the hormone affects

21
Q

What is melatonin?

A

Produced by the pineal gland and affects sleep. In some vertebrates affects pigmentation (eg. frogs). It doesn’t alter our pigment

22
Q

What are the roles of skin coloration?

A

Cryptic, aposematic, communication (sex), thermoregulation, UV protection

23
Q

What is the physiological mechanism of colour change?

A

Similar in most animals that can do this
Hormonal/Nervous system control (1 or other)
Vesicles move via the cytoskeleton
When vesicles are spread out, cell appears dark
When they aggregate in the middle, they appear light

24
Q

What are the different glands in fish and why?

A

Mucus - friction
Granular - toxins
Photophores - chemoilluminescence

25
Q

What were the advantages and disadvantages of armored fish?

A

Enamel (hardest) + Dentine
Adv: Protected from inverts
Dis: heavy, low flex, lay on bottom

26
Q

What are the different types of fish scales?

A
Cosmoid (type of dentine, cosmine.)
Ganoid 
Cycloid (soft ray fin = salmon, trout)
Ctenoid (hard ray fin = perch, bichirs)
Placoid - no overlap
27
Q

What types of glands on amphibians?

A

Mucus - moist gas exchange, prevent desiccation

Granular = toxins

28
Q

What is special about reptile skin?

A

Thick stratum corneum
Arranged in scales and plates, not like fish but overlap = flex, because only skin no bone, fission zone
Also have claws

29
Q

What is the bird integument like?

A
Feet similar to reptile skin
Feathers = dead
Beak is keratanized
Flamingo beak specialized to filter feed
Uropygial gland
30
Q

What are the different types of feathers?

A

Contour, flight (primary, secondaries, coverts), down, bristle

31
Q

What are the different types of hairs in mammals?

A

Guard, under, quills, vibrissae

32
Q

What makes up fur?

A

Under hair and guard hair

33
Q

What are the different glands in mammals?

A

Sebaceous, sweat (eccrine + apocrine (pheromones)), mammary