Epithelia

Question 1

What are the 4 tissues types?

Answer 1

connective, muscle, epithelium, nervous

Question 2

Where is epithelial tissue found?

Answer 2

Lining all body surfaces - epidermis, all internal tubes and cavities (digestive, cardiovascular, respiratory systems)

Question 3

How are all epithelia arranged?

Answer 3

Continuous sheets of tightly bound cells.

Question 4

Main functions of epithelial tissues

Answer 4

Barrier function - boundary between different environments, regulate movement of substances, protect against microbial invasion.

Question 5

What is the name of the surface adjacent to the lumen/external surface?

Answer 5

Apical surface

Question 6

What is the name of the surface adjacent to the interior surface?

Answer 6

Basal surface

Question 7

Which surface of epithelial cells are adhered to each other?

Answer 7

Lateral surfaces

Question 8

What feature of epithelial cells allows the unidirectional transport of molecules?

Answer 8

Epithelial cells are polarised

Question 9

What is the importance of tight junctions between epithelial cells?

Answer 9

Creates an impermeable seal between adjacent cells which prevents water passage

Question 10

What are the names of the junctions that anchor adjacent epithelial cells together? Allowing epithelial tissues to stretch and maintain contact

Answer 10

Desmosomes

Question 11

Function of epithelial tissue in the skin and oral cavity

Answer 11

Physical protection from mechanical abrasion

Question 12

Function of epithelial tissues in the lungs and blood capillaries

Answer 12

diffusion of gases, nutrients and waste between blood and surroundings

Question 13

Function of epithelial tissues in the gastrointestinal tract / renal tubules

Answer 13

Absorption of nutrients

Question 14

Function of epithelial tissues in glands and ducts

Answer 14

Secretion of sweat, mucus, enzymes, hormones

Question 15

How are epithelial tissues classified?

Answer 15

3 ways - cell shape, number of cell layers, apical specialisation

Question 16

What are the possible shapes of epithelial cells?

Answer 16

Squamous, cuboidal, columnar

Question 17

Classification of epithelial tissues based on number of layers

Answer 17

simple, stratified, pseudostratified

Question 18

How can epithelial tissue be pseudostratified?

Answer 18

When columnar cells are arranged in a single layer but appear to be stratified due to the varying location of the nuclei

Question 19

What are the possible apical specialisations of epithelial tissue?

Answer 19

Microvilli, cilia, keratin

Question 20

Function of microvilli

Answer 20

Increase apical SA for absorption

Question 21

Function of cilia

Answer 21

Movement of particulate matter

Question 22

Function of keratin

Answer 22

strong protective apical layer

Question 23

Function of simple squamous epithelia

Answer 23

lines surfaces involved in passive diffusion

Question 24

Location of simple squamous epithelia

Answer 24

Alveoli and endothelium (capillaries)

Question 25

Function of simple cuboidal epithelia

Answer 25

lines small ducts and tubules involved in secretion (glandular epithelium) or absorption

Question 26

Location of simple cuboidal epithelia

Answer 26

Renal tubules, small ducts of salivary glands

Question 27

Function of simple columnar epithelia

Answer 27

Lines absorptive surfaces

Question 28

Location of simple columnar epithelia

Answer 28

small intestine (epithelia has microvilli)

Question 29

Function of ciliated simple columnar epithelia

Answer 29

Ciliary action facilitates transport of ovum from ovary to uterus

Question 30

Location of ciliated simple columnar epithelia

Answer 30

female reproductive tract

Question 31

Function of ciliated pseudostratified columnar epithelia

Answer 31

ciliary action propels mucus containing trapped particles towards pharynx

Question 32

Location of ciliated pseudostratified columnar epithelia

Answer 32

Airways of respiratory system (respiratory epithelium)

Question 33

What cells are modified to form goblet cells?

Answer 33

Columnar epithelial cells

Question 34

Function of goblet cells

Answer 34

synthesise and secrete mucus

Question 35

Location of goblet cells

Answer 35

scattered throughout simple columnar epithelia in the respiratory and gastrointestinal system.

Question 36

Function of stratified cuboidal epithelia

Answer 36

secretory

Question 37

Location of stratified cuboidal epithelia

Answer 37

some secretory ducts and glands. rare

Question 38

function of stratified columnar epithelia

Answer 38

secretory and protective

Question 39

Location of stratified columnar epithelia

Answer 39

male urethra and lining some glands. rare

Question 40

Function of stratified squamous epithelia

Answer 40

protection from mechanical abrasion

Question 41

location of stratified squamous epithelia

Answer 41

oral cavity, epidermis

Question 42

How is stratified squamous epithelia formed

Answer 42

cells mature from continuously dividing cells in the basal layer and gradually migrate to the surface where they shed as anucleate squames

Question 43

what are the apical specialisations of stratified squamous epithelia

Answer 43

non-keratinised or keratinised

Question 44

Function of keratin

Answer 44

enhances resistance to physical stress

Question 45

How is keratin formed?

Answer 45

keratin filaments are accumulated by epithelial cells as they mature, which forms a tough, non-living surface layer

Question 46

Function of transitional epithelium

Answer 46

allows for stretch and expansion

Question 47

location of transitional epithelium

Answer 47

only in bladder

Question 48

How does oral squamous cell carcinoma occur?

Answer 48

Uncontrolled proliferation of dysplastic (abnormal) epithelial cells which destroy and invade adjacent tissues