Chapter 4

Question 1

what is one of the largest organs of the body?

Answer 1

the vertebrate integument

Question 2

what are 8 exasmples of what epidermis forms?

Answer 2

1. hair
2. feathers
3. baleen
4. claws
5. nails
6. horns
7. beaks
8. some scales

Question 3

the superficial layers in contact with the outside environments is the ——–, below it is the —— and between them is the ——- ———

Answer 3

epidermis/dermis/basement membrane

Question 4

epidermies derives from what?

dermis derives from what?

Answer 4

epidermis=ectoderm

dermis=mesoderm and mesenchyme

Question 5

plies:

Answer 5

collagen fibers woven into distinct layers

Question 6

mucus seems to afford some protection from what?

Answer 6

bacterial infection and helps ensure the laminar flow of water across the surface.

Question 7

in terrestrial vertebrates the epidermis covering the body often forms an outer keratinized layer called what?

Answer 7

stratum corneum

Question 8

where dermal contributions predominate, especially in the form of ossified dermal bone, the fold is termed what?

Answer 8

a dermal scale.

Question 9

epidermal scale:

Answer 9

where the epidermal contribution predominates, especially in the form of a thickened keratinized layer.

Question 10

what are the 4 scales?

Answer 10

1. Placoid scale
2. Cosmoid scale
3. Ganoid scale
4. Cycloid-ctenoid scale

Question 11

do fish have a keratinized surface?

Answer 11

no

Question 12

what allows the skin of a fish to bend without wrinkling?

Answer 12

collagen within the dermis

Question 13

do fish have dermal or epidermal scales?

Answer 13

dermal

Question 14

unicellular glands include what 2 cells?

Answer 14

1. club cells

2 granular cells

Question 15

in chondrichthyes or cartilaginous fishes, what is absent and what scales do they have?

Answer 15

dermal bone is absent and placoid scales persist

Question 16

in bony fishes do dermal scales peirce the epidermis?

Answer 16

no

Question 17

do cosmoid scales have more enamel or dentin?

Answer 17

dentin. On top of the dentin is a thin strip of enamel

Question 18

gars have what kind of scales?

Answer 18

ganoid scale

Question 19

ganoid scale is characterized by what?

Answer 19

a thick surface coat of enamel without an underlying layer of dentin. Ganoid scales are shiny because of the enamel

Question 20

what are the 2 kinds of teleost scales?

Answer 20

1. cycloid scale

2. ctenoid scale

Question 21

muticellular glands are more common in the skin of —— than of fishes

Answer 21

tetrapods

Question 22

cutaneous respiration:

Answer 22

a form of gas exchange between the air and capillary beds in the lower epidermis and dermis

Question 23

what is smaller mucous glands or poisoon glands?

Answer 23

mucous

Question 24

if you examine the skin of a larval amphibian you may also find what kind of cells that are thought to secrete antimicrobial products onto the skin surface?

Answer 24

leydig cells

Question 25

what does reptiles have more of and less of compared to amphibians?

Answer 25

more keratinization and less skin glands

Question 26

do reptiles have dermal scales?

Answer 26

no, epidermal scales

Question 27

the junction between adjacent epidermal scales is what?

Answer 27

flexible hinge

Question 28

feathers are non-------- and non--------

Answer 28

nonvascular and nonnervous

Question 29

pterylae:

Answer 29

distinctive tracts in which feathers are found on birds

Question 30

what is feathers embryological origin?

Answer 30

develop embryologically from feather follices, invaginations of the epidermis that dip into the underlying dermis

Question 31

in mammals, the surface keratinized cells are continually lost and replaced by cells arising primarily from the deepest layer of the epidermis, called what?

Answer 31

stratum basale

Question 32

what are the 5 regions of the epidermis in a mammal from bottom to top?

Answer 32

``` 1. stratum basale 2,. stratum spinosum 3. stratum granulosum 4. stratum lucidum 5. stratum corneum ```

Question 33

what 3 things occupy the mammalian dermis but do not reach into the epidermis?

Answer 33

1. blood vessels 2. nerves 3. smooth muscles

Question 34

define nails:

Answer 34

are plates of tightly compacted cornified eithelial cells on the surface of fingers and toes

Question 35

only ------- have nails

Answer 35

primates

Question 36

what is the material found under nail, claw, or hoove?

Answer 36

subunguis

Question 37

true antlers:

Answer 37

occurs in members of the family cervidae (deer,elk and moose). typically only males have antlers and they are branched and shed annually

Question 38

true horns:

Answer 38

are found among members of the family bovidae (cattle, sheep, antelope, goats, bison etc). Commonly horns occur in both males and females and retained year round and continue to grow throughout the lifetime of the individual. The horn is unbranched and formed of a bony core and a keratinized sheath

Question 39

the integument within the mouth of whales forms plates of --------- that act as strainers to extract krill from watrr gulped in the distended mouth

Answer 39

baleen

Question 40

does baleen contain bone?

Answer 40

no