Epithelial tissue

Question 1

how many functions of skin are there

Answer 1

7

Question 2

name all functions of skin

Answer 2

protection
containment
thermoregulation
immunological defences
sensory abilities
communication
appendages

Question 3

describe protection (functions of skin)

Answer 3

skin resists abrasion and penetration
blocks entry of foreign material, pathogens, UV rays

Question 4

describe containment (functions of skin)

Answer 4

skin prevents loss of body fluids
skin is waterproof

Question 5

describe thermoregulation (functions of skin)

Answer 5

controls transfer of heat across body’s surface
facilitates heat retention and dissipation (sweat and temp regulation)

Question 6

describe sensory abilities (functions of skin)

Answer 6

sensations
touch
hair (air between hair keeps you warm)

Question 7

describe communications (functions of skin)

Answer 7

skin releases visual and pheromone signals

Question 8

describe appendages (functions of skin)

Answer 8

hair
nails
sebaceous glands
sweat glands

Question 9

ALL EPITHELIAL TISSUE…

Answer 9

RESTS ON A BASEMENT MEMBRANE

Question 10

what is basal lamina

Answer 10

basement memebrane

Question 11

what doesn’t H&E stain

Answer 11

the BM
can only see it sometimes depends on plane of section (can see more clear in hair and respiratory tract)

Question 12

what is only below the BM

Answer 12

blood vessels and extracellular space

Question 13

name the layers of skin

Answer 13

epidermis
dermis
hypodermis

Question 14

name the stratums (BM and up)

Answer 14

stratum corneum
stratum granulosum
stratum spinosum
stratum germinativum

Question 15

describe stratum germinativum

Answer 15

layer of columnar cells resting on BM
stem cells - can divide and become themselves or differentiate to layer above
growth is apical (apical level used to name tissue)

Question 16

describe stratum spinosum

Answer 16

polygonal shape cells
between cells = spines = desmosomes which connect cells together

Question 17

describe stratum granulosum

Answer 17

cells are becoming flat
have keratohyalin granules that produce keratin
~ 30 day turnover, makes granules, bursts and gives next stratum

Question 18

describe stratum corneum

Answer 18

stratified squamous keratinized
cells explode and form keratin sheets

Question 19

what does covering epithelia mean

Answer 19

covers body and organs

Question 20

name all types of tissue (epithelia)

Answer 20

simple squamous
simple cuboidal
simple columnar
stratified squamous (keratinized and non keratinized)
transitional
pseudostratified columnar
glandular epithelia

Question 21

what does lamina propria mean

Answer 21

generally describe connective tissue

Question 22

describe simple tissues

Answer 22

squamous = one layer flat cells
cuboidal = one layer cube shaped cells
columnar = more tall than wide, could have cilia

the way it looks depends on PLANE OF SECTIONNNNN

Question 23

describe transitional epithelium

Answer 23

covers bladder - cells expand with it
changes shape often

Question 24

describe pseudostratifed columnar

Answer 24

pseudo = fake, looks stratified but is simple
found in respiratory tract
goblet cells!

Question 25

describe staining of BM

Answer 25

glucose moiety + periodic acid = aldehyde moiety PAS reaction red/fuchsia stain can see BM

Question 26

describe composition of BM

Answer 26

proteoglycans glycoproteins collagen layer of reticular fibers (underlies BM)

Question 27

describe proteoglycans

Answer 27

look like test tube brush cleaner protein core 50/50 sugar and proteins glycosaminoglycans = GAGs

Question 28

describe GAGs

Answer 28

negatively charged and hold water

Question 29

give ex of proteoglycans

Answer 29

heparan sulphate - synthesized by epithelial cells

Question 30

describe glycoproteins

Answer 30

10% sugars and 90% protein protein backbone 3 sugars and modified sugar at end

Question 31

name types of glycoproteins (3)

Answer 31

laminin Nidogen-1 (Enactin) Fibronectin

Question 32

describe laminin (glycoproteins)

Answer 32

cross shaped links surface of epithelial cells to BM (helps it stick)

Question 33

describe Nidogen-1 (Enactin) (glycoproteins)

Answer 33

small glycoprotein essential component for BM

Question 34

describe fibronectin (glycoproteins)

Answer 34

adhesive that binds plasma membrane of epithelial cells to heparan sulphate - like glue

Question 35

describe collagen

Answer 35

part of ECM stains bright pink

Question 36

name and describe collagens of BM

Answer 36

type IV = synthesized by epithelial cells type VII = anchoring filaments (filaments/fibers and anchors) type III - reticular fibers

Question 37

how many functions of BM are there

Answer 37

5

Question 38

name all functions of BM

Answer 38

1 - structural attachment 2 - compartmentalization 3 - filtration 4 - maintain polarity 5 - tissue scaffolding

Question 39

describe structural attachment (functions of BM)

Answer 39

attachment of epithelial cells to connective tissue

Question 40

describe compartmentalization (functions of BM)

Answer 40

isolate epithelial cells and muscle cells (tissue types) bundle and separate stuff

Question 41

describe filtration (functions of BM)

Answer 41

movement of molecules is partly regulated by ionic charges important for kidneys (filtration mechanism)

Question 42

describe helps maintain polarity (functions of BM)

Answer 42

how cells know basal membrane from apical layers if they don't know which way is up then they keep dividing and causes problems like skin cancer (when polarity is off) intermediate filaments = no polarity

Question 43

describe tissue scaffolding (functions of BM)

Answer 43

helps to scaffold regeneration need BM to generate and stabilize cells and create upper layers

Question 44

name and describe all characteristics of epithelial tissues (6)

Answer 44

1- cells are closely associated with little extracellular space 2 - cells are strongly attached via intracellular junctions 3 - lines body surfaces and cavities 4 - specialization - absorption, secretion, sensation and contractility - depends on where tissue is found 5 - cells are polarized 6 - epithelial tissues rest on A BASEMENT MEMBRANE

Question 45

what is a scar

Answer 45

regrowing BM discolouration due to melanocytes