Chapter 6: Integument

Question 1

What are the functions of the integument?

Answer 1

o Protection, thermoregulation, water balance, sensory reception, glands, a variety of derivatives, coloration
o Can make mineralized tissues

Question 2

Examples of mineralized tissues the integument can make

Answer 2

Examples: enamel, dentin, bone

Enamel: mineralized tissue made from integument, made by ameloblasts
Dentin: mineralized tissue made from integument, made by odontoblasts

Question 3

What are the 2 primary parts of the integument and from which embryonic germ layers are they derived?

Answer 3

o Dermis from mesoderm
o Epidermis from ectoderm

Question 4

What is the function of the stratum basale?

Answer 4

Its main function is to continuously produce new keratinocytes (skin cells)

Question 5

What is the stratum corneum?

Answer 5

It’s composed of dead, flattened keratinocytes that are filled with keratin, a protein that helps protect your skin against environmental damage like bacteria, UV radiation, and water loss

Question 6

What is the function of the dermal papilla?

Answer 6

Dermal papilla induces the epidermis

General development occurs and then differentiation can occur in various ways, such as feathers, teeth, scales, hair, and glands

Question 7

What are chromatophores?

Answer 7

pigments to produce color

Question 8

Types of chromatophores?

Answer 8

melanophores, Xanthophores, Erythrophores, Iridiophores

Question 9

Melanophores

Answer 9

black and brown, produced by melanin

Question 10

Xanthophores

Answer 10

contain yellow pteridine pigments

Question 11

Erythophores

Answer 11

contain red/orange carotenoids

Question 12

Iridiophores

Answer 12

contain crystals that create blue and green colors

Question 13

Hypodermis

Answer 13

transitional subcutaneous region made up of very loose connective and adipose tissues

Question 14

Unicellular glands of fishies!

Answer 14

club cells, granular cells

Question 15

Mutlicellular glands of fishies?!

Answer 15

hagfish mucous glands, granular venom glands (associated with fin spines)

Mucous glands contain residul fluid, thread skeins, many small mucin vesicles; flows through slime thread cells

Venom glands are made up of channel, venom gland beside it, integumentary sheath, and venom duct

Question 16

Epidermis

Answer 16

• Relatively thin, usually made of living cells
• No stratum corneum
• Unicellular glands: club cells, granular cells
• Often a mucous cuticle on surface

Question 17

how are collagen fibers oriented in the fish dermis?

Answer 17

packed tight together

• Plies of collagen of the stratum compactum of fish skin: flexible bias of the skin is oriented at 45° to the body length, thus accommodating lateral bending during swimming
• Keeps the skin flexible but tight (surface doesn’t wrinkle and create turbulence as the fish swims)

Question 18

Fish to note when it comes to scales? Describe them

Answer 18

• Note: onstracoderms and placoderms have dermal armor
• Bony fish: dermal scales
• Note: primitive actinopterygian had scales made up of lamellar bone

Question 19

Name the 4 types of fish scales

Answer 19

placoid, cosmoid, ganoid, and cycloid/ctenoid

Question 20

Placoid

Answer 20

have spine, basal plate
Example: sharks

Question 21

Cosmoid

Answer 21

includer layers(in order) of enamel, dentin(cosmine), then bone( vascular and lamellar bone)

Examples: primitive sarcopterygians

Question 22

Ganoid

Answer 22

include layers (in order) enamel(ganoin), bone (vascular and lamellar bone)
Example: polypteriforms and gars

Question 23

Cycloid/Ctenoid

Answer 23

either or, cycloid made of multiple even circle layers(think layers of tree growth), while ctenoid curved around one side (think fingerprint or rainbow
 Aka dermal scales
 Example: teleosts

Question 24

Why are teleost scales called dermal scales?

Answer 24

scales are right up against the epidermis