Epithelium and integument

Question 1

What is integument

Answer 1

Includes the skin coverings surface of body and specialized derivatives

Question 2

Types of integument

Answer 2

nails, claws, & beaks
– feathers, scales, & hair
– sebaceous, sweat, & other glands

Question 3

List several functions of integument (8)

Answer 3

– Protection of underlying tissues
– Reception of tactile, thermal, or pain stimuli
– Prevent desiccation
– Respiration (mainly in amphibians)
– Provides insulation (hair, feathers, adipose tissue)
– Can increase heat loss by changes in hair or feather position or by increased evaporative water loss (sweating)
– Removal of excess water and salts
– Production of vitamin D

Question 4

What are the two main layers of integument

Answer 4

Epidermis, dermis

Question 5

what is the epidermis and what is it made of

Answer 5

Upper layer (ectodermal origin) of specialized epithelium

Question 6

what is the epidermis in the embryo

Answer 6

periderm

Question 7

Epithelial tissues have a ___ surface and an ___ surface, found ___ the body, NOT ___ to integument

Answer 7

free, attached, throughout, restricted

Question 8

Basement membrane anchors ___ to ___ via ___ tissue fibers. Composed of ___ and ___ lamina.

Answer 8

epidermis, dermis, connective, basal (epi), reticular (derm)

Question 9

Features of epidermis
simple or stratified?
Keratinized?
thick or thin?
does it have a mucous cuticle?

Answer 9

Can be simple or stratified, keratinized or non-keratinized, thick or thin, may have mucous cuticle

Question 10

what is the dermis

Answer 10

Dense connective tissue layer (mesodermal origin) deep to the epidermis, with sensory endings (tactile, thermal, pain)

Question 11

what is the dermis made of

Answer 11

Composed of stratum laxum and stratum compactum

Question 12

the dermis rests upon the ___ (___ origin) of ___ and other connective tissue. If thick, hypodermis is termed ___

Answer 12

hypodermis, mesodermal, adipose, superficial fascia

Question 13

Hypodermis rests upon ___ (___ origin).

Answer 13

muscle, mesodermal

Question 14

epidermis evolvement

Answer 14

ectoderm, periderm, epidermis

Question 15

three features of epithelia

Answer 15

cell shape, cell laying, surface specializations

Question 16

what are the three cell shapes and describe them

Answer 16

Squamous – very flat cells, width greater than height
– Cuboidal – height and width approximately equal
– Columnar – cell height greater than width

Question 17

four types of cell layering

Answer 17

simple, stratified, transitional epithelium, pseudostratified

Question 18

what is simple cell layering

Answer 18

single layer of cells on the basement membrane

Question 19

what is stratified cell layering

Answer 19

two+ layers of cells stacked on each other, only basal layer touches basement membrane. Shape of apical layer determines the “shape” designation (most basal layers are cuboidal

Question 20

what is transitional epithelium cell layering

Answer 20

a specialized type of stratified cuboidal found in the urinary system, appears stratified squamous when stretched

Question 21

what is pseudostratified cell layering

Answer 21

simple epithelium gives the illusion of being stratified – all cells sit on the basement membrane, nuclei of cells are at various levels

Question 22

what are the surface specializations

Answer 22

Cilia (motile), microvilli (increase surface area), & stereocilia (neuro/secretion)

Question 23

describe structure of epidermis in amphioxus

Answer 23

simple columnar or simple
cuboidal

Question 24

describe structure of epidermis in lamprey

Answer 24

stratified cuboidal

Question 25

describe structure of epidermis in scaled fish

Answer 25

stratified cuboidal or stratified squamous

Question 26

describe structure of epidermis in amphibian

Answer 26

very thinly keratinized stratified squamous

Question 27

describe structure of epidermis in reptiles

Answer 27

keratinized stratified squamous

Question 28

describe structure of epidermis in birds

Answer 28

keratinized stratified squamous

Question 29

describe structure of epidermis in mammals

Answer 29

keratinized stratified squamous

Question 30

Keratin is at type of intermediate ___, keratinized cells ___ at maturity

Answer 30

filament, dead

Question 31

what gets keratinized

Answer 31

stratum corneum of epidermis

Question 32

can keratinization level vary in an animal

Answer 32

Keratinization level can vary by region within an animal: Thick and Thin Skin (Human)

Question 33

what is the bulk of the hypodermis

Answer 33

adipose connective tissue

Question 34

what is the bulk of the upper epidermis

Answer 34

areolar connective tissue

Question 35

what is the bulk of dermis

Answer 35

dense connective tissue

Question 36

what are the two dermal layers

Answer 36

stratum laxum (spongioso, spongiosum), or stratum compactum

Question 37

where is the stratum laxum and describe it where is it descirbe the connective tissue what layer is it in mammals is it vascualr

Answer 37

Upper layer deep to the basement membrane, loosely packed connective tissue (papillary layer in mammals), is vascular

Question 38

what is special about fish and stratum laxum

Answer 38

in fish, scales may be presen

Question 39

what is special about stratum laxum and chromatophores

Answer 39

Chromatophores (pigment producing cells) from neural crest tissue typically reside here (rarely in epidermis), but pigments may be transferred to epidermis

Question 40

where is the stratum compactum and describe it where what tissue what layer in mammals is it vascualr

Answer 40

Deep to stratum laxum, composed of dense connective tissue, (reticular layer in mammals), is vascular

Question 41

where is the hypodermis and describe it where what tissue is it made of 2x what corpuscles and is it vasucalr

Answer 41

deep to dermis, composed mainly of adipose tissue, may contain connective tissue septa, nerves and sensory corpuscles, is vascular

Question 42

Note – epidermis is ___ in most vertebrates (exceptions), dermis brings ___ in close contact to epidermis

Answer 42

avascular, blood vessels

Question 43

in fish skin scales are of ___ origin, but are found at the interface between the ___ and ___

Answer 43

dermal, epidermis, dermis

Question 44

do endocrine glands have ducts

Answer 44

no

Question 45

do exocrine glands have ducts

Answer 45

yes

Question 46

do uni-cellular glands exist

Answer 46

yes

Question 47

3 exocrine glands and where are they located

Answer 47

merocrine (eccrine), apocrine, holocrine: epidermis

Question 48

merocrine glands what do they do

Answer 48

ecretory products packaged into vesicles, fuse with membrane to secrete product into lumen of gland by exocytosis

Question 49

types of merocrine gland

Answer 49

Most common type of exocrine gland. Mucous, Serous, and Mixed types

Question 50

examples of merocrine glands

Answer 50

eccrine sweat glands are merocrine/eccrine glands

Question 51

describe apocrine

Answer 51

No vesicles, products and apical portion of the cell (including plasma membrane) is pinched off as the secretion

Question 52

ex of apocrine gland

Answer 52

Mammary glands are apocrine gland

Question 53

describe holocrine glands

Answer 53

Apical cells fill with the product before the entire cell dies and is released. Cell disintegrates, releasing product

Question 54

ex of holocrine gland

Answer 54

Meibromian (tarsal) gland of the eye and sebaceous glands are holocrine glands

Question 55

Describe mucous glands, including secretion, nuclei, cytoplasm, and what is prominent about it

Answer 55

Secrete viscous highly glycosylated glycoproteins. Nuclei are flat and found near basement membrane. Cytoplasm stains lightly. More prominent lumen than serous glands

Question 56

describe serous glands, including what they secrete, ex, what is secretory unit shape, nuclei, and cell shape

Answer 56

Secrete watery enzyme-rich products, (digestive enzymes produced by the pancreas and salivary glands). Secretory unit is usually alveolar or acinar shape. Nuclei are rounded or oval, cell are basophilic when stained (blue) due to abundant RNA in cytoplasm for protein synthesis

Question 57

describe mixed glands, including what they contain

Answer 57

Either have mix of mucous and serous cells within an secretory end piece, or a mix of mucous and serous end pieces with in a compound gland

Question 58

describe a feature of mucous cells and their lumen

Answer 58

Mucous Glands have moderately large lumen generally filled with secretion.

Question 59

shape of serous glands

Answer 59

Serous glands are rounded to pear-shaped alveoli (acinar) – cells pyramidal; around small lumen

Question 60

feature of mixed sero-mucous cells

Answer 60

has tubules

Question 61

Non-Mammalian Vertebrate Skin Glands

Answer 61

mucous and poison glands, femoral glands, uropygial glands

Question 62

describe mucous and poison glands who has then purpose of both

Answer 62

Found in fish and amphibians – Mucous glands aid in keeping skin moist, important for cutaneous respiration – Poison glands produce noxious substances as defense mechanisms against predators

Question 63

describe femoral glands who has them where are they purpose

Answer 63

Found in reptiles – Located on underside of thigh in male lizards, opens through short duct passing through a spike-like projections, presumed function in attraction of mates

Question 64

uropygial glands who has them where what do they do what do they contain

Answer 64

Preening glands of birds – Only integumentary glands in birds, located at the base of tail on dorsal side. Are compound glands with secretions containing oils and wax (lipids), waterproofs feathers and functions in beak and feather maintenance