Exam 1 - Integument

Question 1

What two layers make up the integument?

Answer 1

Epidermis + Dermis

Question 2

From what embryonic tissue does the epidermis originate?

Answer 2

Ectoderm

Question 3

From what embryonic tissue does the dermis originate?

Answer 3

Mesoderm

Question 4

What are the basic components of the Epidermis?

Answer 4

Squamous epithelium, mucus glands, granular glands, stratum germinativum, basal lamina/basement membrane

Question 5

What are the basic components of the Dermis?

Answer 5

Stratum laxum and stratum compactum. Contains collagenous fibers.
Contains chromatophores, melanophores, iridiophores.
Contains: dermal derivatives (bone and bony structures).

Question 6

What layers make up the epidermis of fishes?

Answer 6

Stratified squamous epithelium, very few keratinized cells, unicellular mucus glands

Question 7

What layers make up the dermis of fishes?

Answer 7

Connective tissue fibers, dermal bone (acellular): plates (armor), denticles, scales (different types).

Question 8

What are the components of the epidermis of amphibians?

Answer 8

stratum corneum, abundant mucus glands (multicellular) reaching into dermis, granular glands (producing toxins: parotid gland, poison glands).
Epidermis structure related to life history and biology of amphibians.

Question 9

What are the components and characteristics of reptile skin?

Answer 9

This stratum corneum, more waterproof than amphibians, organized as horny plates in turtles, horny scales in squamates.
Molting
Modifications of the skin: claws (hardened by adding calcium slats to keratin), setae, plates, modified ventral scales of snakes (scutes).
No mucus glands.

Question 10

What are the notable feature in the dermis of reptiles

Answer 10

Chromatophores.

Question 11

List the features of bird epidermis

Answer 11

relatively thin, not heavily cornified, except in certain regions.
Horny scales on legs, feet.
Claws
Horny beak
Feathers: form the flying surface of wings and tail, cover the body, trap air, reduce evaporative loss, insulate the body. Embedded into skin in a follicle.

Question 12

What are the types and structures of feathers?

Answer 12

Contour feathers: regular and flight feathers.
Feather structure: central axis, calamus (quill), rachis, vane, barbs and barbules, hooklets.
Down.

Question 13

What are the characteristics of bird dermal tissue?

Answer 13

Relatively thin layer. Interlacing collagen fibers, sensory receptors.
Muscle fibers to move the feathers.
No ossifications

Question 14

List the characteristics of Mammal skin

Answer 14

Very thick, many layered stratum corneum.
S. corneum especially thickened on soles, palm, foot pads
main epidermal derivative: hair

Question 15

What are the components, features, and characteristics of hair?

Answer 15

Hair follicle, root, hair papilla, hair shaft.
Hair moved by the arrector pili muscles attached to one side of follicle. Absent in marine mammals. Evidence of presence: goose bumps, hackles.
Hair extent and coarseness: depends on location on body.

Question 16

Mammalian epidermal modifications:

Answer 16

claws, nails, hooves, horns, antlers, baleen, epidermal plates.

Question 17

Mammalian Epidermal glands:

Answer 17

Multicellular. Cebaceous (holocrine), sweat (eccrine and apocrine) and mammary glands (modified apocrine sweat + sebaceous).

Question 18

Mammalian dermal tissue features:

Answer 18

Dermal bone uncommon (armadillos have bone under keratinized epidermal plate).
Skull and pectoral girdle develop at the very base of skin or just under it.
Extensive vasculature.
Capillary beds common.
melanocytes: abundance varies with different human populations.