Integument

Question 1

what are the 6 major views for labelling drawings?

Answer 1

rostral: toward nose
caudal: toward tail
ventral: toward belly
dorsal: toward back
medial: toward middle
lateral: toward side

Question 2

What are the 3 major axes for labelling drawings?

Answer 2

rostral-caudal
dorsal-ventral
medial-lateral

Question 3

What are 3 major planes for labelling biological drawings?

Answer 3

horizontal plane (plane splitting horizontally in half)
coronal plane (plane splitting front from back)
sagittal plane (plane between eyes/down spine)

Question 4

What are the 3 major layers of the skin?

Answer 4

epidermis
dermis
hypodermis

Question 5

What are the major functions of the skin?

Answer 5

protection
barrier
regulator
sensory

Question 6

What kind of secretory cells does the skin have?

Answer 6

mucoid
proteinaceous

Question 7

What do mucoid cells do?

Answer 7

produce mucus

Question 8

What do proteinaceous cells do?

Answer 8

produce slimes, poisons

Question 9

Which of the 3 layers is the surface/outer layer?

Answer 9

epidermis

Question 10

What are the 3 components of the epidermis?

Answer 10

stratum corneum: outermost layer
ketatins
stratum germinativum: innermost layer

Question 11

Which is the outermost layer of the epidermis?

Answer 11

stratum corneum

Question 12

What are keratins?

Answer 12

fibrous proteins found in the epidermis that can be alpha keratin or beta keratin types

Question 13

Describe alpha keratin; where are they found?

Answer 13

relatively soft (can be hard)
component of hair, nails, horns

found in the epidermis

Question 14

Describe beta keratin; where are they found?

Answer 14

hard
component of feathers, reptilian scales, claws, beaks

found in the epidermis

Question 15

Where do keratinocytes mature?

Answer 15

in the stratum spinosum

Question 16

What is the innermost layer of the epidermis? What is significant about it?

Answer 16

stratum germinativum

the main site of cell division

Question 17

Where is the main site of cell division in the epidermis?

Answer 17

the stratum germinativum

Question 18

Describe the basic make up of the dermis

Answer 18

it’s a meshwork of collagenous and elastic fibers

it has two layers:
stratum spongiosum
stratum compactum

also contains
- mechanoreceptors
- nerves
- blood vessels
- other structures such as hair follicles, sweat glands

Question 19

What are the two layers of the dermis?

Answer 19

stratum spongiosum
stratum compactum

Question 20

What two types of fibers are found in the dermis?

Answer 20

collagenous
elastic

Question 21

Aside from fibers, what other
things are found in the dermis?

Answer 21

mechanoreceptors
blood vessels
nerves
depending on the groups, some have hair follicles, sweat glands

Question 22

What is the hypodermis made of?

Answer 22

connective and adipose tissue

Question 23

what is the scale bar formula?

Answer 23

drawing size/ actual size = X mm length of scale bar / mm represents scale bar

ex.
drawing size = 120 mm
actual size = 0.8 mm
represents scale bar = 0.1 mm

length of scale bar = (120 x 0.8) / 0.1 = 15 mm

Question 24

What is the germ tissue origin of the epidermis?

Answer 24

ectoderm

Question 25

What germ tissue did the dermis arise from?

Answer 25

mesoderm

Question 26

What separates the epidermis and the dermis?

Answer 26

the basement membrane which is a non-cellular layer

Question 27

T or F: the epidermis is generally thicker than the dermis

Answer 27

false the dermis is usually thicker than the epidermis

Question 28

Which contains more cell types: dermis or epidermis?

Answer 28

the epidermis

Question 29

Briefly describe the epidermis of bony fish

Answer 29

non-keratinized thin glandular coated with a non-cellular cuticle produced by mucus cells many mucus cells present glands are near the surface of the epithelium multiple types of cells can be present: epithelial, mucus, club

Question 30

Are bony fish integuments keratinized?

Answer 30

no

Question 31

Describe the basic structure of bony fish integuments

Answer 31

thin, glandular, mucus coating, non-keratinized

Question 32

What is the purpose of the mucus cuticle coating bony fish?

Answer 32

reduces drag in water (improves flow of water across the skin surface) protection against infection participates in osmoregulation predator evasion = makes them slippery, and sometimes includes toxic chemicals

Question 33

What are the 3 common types of cells in bony fish epidermis?

Answer 33

epithelial mucus club

Question 34

Describe the dermis of fish

Answer 34

thin composed of loose and dense connective tissues features: - chromatophores - mast cells - scale beds - scales

Question 35

Where do fish scales originate?

Answer 35

from the dermis

Question 36

How does the origin of fish scales compare to scales in tetropods?

Answer 36

fish scales originate from the dermis, whereas tetrapod scales originate from the epidermis

Question 37

How do scales in cartilaginous fishes (Chondrichthyes) differ to those in bony fish?

Answer 37

cartilaginous fish have placoid scales which are not flat like those in bony fish, but look like shark teeth

Question 38

In what way does amphibian integument not represent the skin of fish?

Answer 38

lacks scales surface skin cells are keratinized

Question 39

The stratum corneum is best developed in what type of amphibians?

Answer 39

ones that spend more time on land these cells are molted in sheets occasionally

Question 40

What causes warts on toads?

Answer 40

local thickenings of cells

Question 41

What is the major function of the integument for most amphibians?

Answer 41

major respiratory organ

Question 42

How does the skin contribute to respiration in amphibians?

Answer 42

the dermis has many blood vessels and lymph spaces for gas exchange

Question 43

How does amphibians prevent water loss when they're on land?

Answer 43

mucus glands in their epidermis-dermis secrete a mucus cuticle to keep their skin moist

Question 44

Where are poison glands located in amphibian skin?

Answer 44

the epidermis

Question 45

How have reptiles 'airproofed' their skin?

Answer 45

use of keratin and lipids

Question 46

How has the reptilian integument been modified for life on land?

Answer 46

the epidermis has been hardened to cover the reptile in horny scales

Question 47

What do snakes and lizards molt?

Answer 47

their entire epidermis layer

Question 48

What composes the reptilian epidermis?

Answer 48

first layer is characterized by beta-keratin - tough, thick, dead, and acellular layer deeper layer is characterized by alpha-keratin

Question 49

What is a major component of fish and amphibian skin which reptilian skin is lacking?

Answer 49

mucus glands - reptiles do not have mucus glands

Question 50

What are scutes?

Answer 50

layers of overlapping keratinized scales of epidermal origin in some reptiles (crocodiles, tortoises) that are not shed, but instead layered over time

Question 51

What is the major difference between bird skin and all other vertebrates?

Answer 51

the presence of feathers

Question 52

Where do feathers originate from?

Answer 52

the epidermis

Question 53

What is a second major difference between bird skin and other vertebrates? But common between non-bird reptiles?

Answer 53

non-glandular just one single gland

Question 54

How many glands are present in the bird integument? What is/are the function(s)?

Answer 54

1 secretes oil for preening and waterproofing

Question 55

What type of keratin are feathers made of?

Answer 55

beta

Question 56

How do the epidermis and dermis of mammals grow in relation to one another?

Answer 56

they are interwoven through epidermal and dermal ridges

Question 57

How is mammal skin classified as thin or thick?

Answer 57

by the extent to which the outermost layer of the epidermis is keratinized

Question 58

Where is thick mammalian skin typically found?

Answer 58

in areas of the body where there's more abrasion (ex. bottom of feet, hands)

Question 59

What are some examples of skin derivatives in mammals? where do they originate?

Answer 59

hair sebaceous glands sweat glands nails epidermal

Question 60

Describe the connection between hair, hair follicles and sebaceous glands in mammals

Answer 60

a strand of hair is composed of a cornified shaft and a root with a hair follicle sebaceous glands secrete sebum (oil) into the neck of a hair follicle

Question 61

In mammals, what gland types develop in association with hair follicles and which do not?

Answer 61

do: sebaceous glands do not: sweat glands

Question 62

What are two other features of mammalian skin?

Answer 62

blood vessels adipose tissue

Question 63

What is the purpose of skin derivatives such as hair in mammals?

Answer 63

heat retention