Epithelial Tissue

Question 1

what are some features of epithelial tissue

Answer 1

• lines all the body surfaces
• provides a barrier function
• arranged in continuous sheets of tightly bound cells
• provide protection against microbial invasion
• regulate movement of substances
• polarised

Question 2

what are the three specialisations of epithelial tissues

Answer 2

apical, basal and lateral

Question 3

what is the apical surface of epitherial cells

Answer 3

the upper free surface exposed to the exterior

Question 4

what is the basal surface of epitherial cells

Answer 4

basement membrane - the lower, attached surface

Question 5

what are lateral surfaces in epithelial cells

Answer 5

intercellular junctions - can also form folds and processes between neighboring cells to increase the surface area for fluid transport.

Question 6

what are the three junctions in epithelial tissue

Answer 6

• tight junctions
• desmesomes
• gap junctions

Question 7

what are tight junctions

Answer 7

these are cells held tightly together by individual groups of tight junction proteins. they prevent water passage by arranging in strands and forming a branched network

Question 8

what is an example of the purpose of tight junctions in epithelial cells

Answer 8

tight junctions between the epithelial cells lining the bladder prevent urine from leaking out into the extracellular space

Question 9

what are desmosomes

Answer 9

spot welds between adjacent epithelial cells that allow cells that stretch such as skin and cardiac muscle by remaining unconnected in an unbroken sheet

Question 10

how do desmosomes remain unconnected in sheets

Answer 10

caherins attached to a structure called the cytoplasmic plaque, which connects to intermediate filaments

Question 11

what are gap junctions

Answer 11

channels between neighboring cells that allow for the transport of ions, water and ions

Question 12

how do gap junctions form

Answer 12

six connexons form a donut like structure, which when aligned forms a channel between cells

Question 13

where are gap junctions important

Answer 13

cardiac muscle

Question 14

what are connexons

Answer 14

membrane proteins

Question 15

what are the functions of epithelial tissues

Answer 15

• physical protection
• diffusion
• absorption
• secretion

Question 16

how can epithelial structure differ

Answer 16

• shape
• number of cell layers
• apical specialisations

Question 17

what are the different shapes of cells

Answer 17

squamous
cuboidal
columnar

Question 18

what are the different names for the number of layers of epithelial cells

Answer 18

• simple
• stratified
• pseodostratified

Question 19

what does simple mean

Answer 19

a single layer of cells

Question 20

what does stratified mean

Answer 20

multiple

Question 21

what does pseudostratified mean

Answer 21

one layer of cells has alternating nuclei locations which leads to fake multilayer

Question 22

what are the different apical specialisations

Answer 22

• microvilli
• cilia
• keratin

Question 23

what does simple squamous epithelium line

Answer 23

lines surfaces involved in passive diffusion

Question 24

what are some locations of simple squamous epithelia

Answer 24

alveoli in lungs and capillaries in the endothelium

Question 25

what does simple cuboidal epithelium line

Answer 25

lines ducts and tubules and controls absorption or secretion

Question 26

where are simple cuboidal epithelia found

Answer 26

renal tubules and small ducts of salivary glands

Question 27

which surfaces are simple columnar found on

Answer 27

absorptive surfaces

Question 28

where are simple columnar epithelia found

Answer 28

in the small intestine

Question 29

where are microvilli found in the body

Answer 29

small intestine

Question 30

what does it mean if epithelia is keratised

Answer 30

has keratin ie is hard

Question 31

what is an ulceration

Answer 31

a break in the continuity of the epithelium

Question 32

what is a glomerulus

Answer 32

a cluster of capillaries around the end of a kidney tubule

Question 33

what is the difference between proximal convulated tubules and distal convulated tubules

Answer 33

proximal stains more intensely because they contain more organelles which support all the processes required to facilitate active reabsorption

Question 34

what is the function of microvilli

Answer 34

increase the surface area of the apical surface and facilitate the function of absorption

Question 35

where is the pseudostratified epithelium found

Answer 35

only in the respiratory tract

Question 36

what does the structural arrangement of epithelial tissues depend on

Answer 36

location and function of tissue

Question 37

what body surfaces do epithelia cover

Answer 37

all of them

Question 38

what is the epidermis

Answer 38

the outer layer of skin

Question 39

what is the barrier function of the epithelial tissues

Answer 39

- all substances entering and leaving the body pass through the epithelium - it acts as a continuous boundary between different environments

Question 40

how are all epithelia arranged

Answer 40

continuous sheets of tightly bound cells

Question 41

what is the apical surface

Answer 41

adjacent to or facing the external surface

Question 42

what is the basal surface

Answer 42

adjacent to or facing the interior surface

Question 43

what are the lateral surfaces

Answer 43

adhered to each other

Question 44

what are the features common to all epithelial tissues

Answer 44

structure of continuous sheets of cells that are tightly bound together and are polarised. function of covering and lining surfaces to form a barrier

Question 45

which epithelial tissues provide physical protection from mechanical abrasian

Answer 45

skin and oral cavity

Question 46

which epithelial tissues provide diffusion of gases, nutrients, and waste between blood and surrounding tissues

Answer 46

lungs and blood capillaries

Question 47

which epithelial tissues absorb nutrients

Answer 47

the gastrointestinal tract and renal tubules

Question 48

which epithelial tissues secrete sweat, mucus, enzymes and hormones

Answer 48

glands and ducts

Question 49

which shape of epithelial cells can exist in a pseudotratified structure

Answer 49

columnar

Question 50

what do microvilli do in relation to the apical surface area

Answer 50

increase it

Question 51

what do cilia regulate

Answer 51

movement of particular matter

Question 52

what does keratin do

Answer 52

provide a strong protective apical layer

Question 53

what does ciliated simple columnar function

Answer 53

ciliary action facilitates the transport of ovum from the ovary to the uterus in the female reproductive tract

Question 54

what is the function of pseudstratified colmumnar ciliated

Answer 54

propels the surface layer of mucus containing trapped particles toward the pharynx in the airways of reproductive tracts

Question 55

what are goblet cells

Answer 55

modified columnar epithelial cells

Question 56

what is the function of goblet cells

Answer 56

synthesise and secrete mucus

Question 57

where are goblet cells located

Answer 57

scattered throughout simple columnar epitheliums like in the respiratory and gastrointestinal tract

Question 58

what is the function of stratified cuboidal epithelium

Answer 58

secretory

Question 59

where is stratified cuboidal epithelium found

Answer 59

some secretory ducts and glands

Question 60

where is stratified columnar found

Answer 60

male urethra and lining some glands

Question 61

what is the function of stratified columnar cells

Answer 61

secretory and protective

Question 62

what is the function of stratified squamous epithelia

Answer 62

protect from mechanical abrasion.

Question 63

what do stratified squamous cells mature from

Answer 63

basal layer from continuously dividing stem cells

Question 64

what are stratified squamous epithelia shed as

Answer 64

anucleate squames

Question 65

where are stratified squamous epithelium found

Answer 65

in the oral cavity and on the epidermis

Question 66

what does keratin do

Answer 66

enhances resistance to physical stress

Question 67

what do epithelial cells accumulate as they mature

Answer 67

keratin filaments

Question 68

how is a tough, non living surface layer of cells on the apical layer formed

Answer 68

by the accumulation of keratin in the stratified squamous epithelia

Question 69

what does transitional epithelium do

Answer 69

allows for expansion and stretch

Question 70

where is transitional epithelium found

Answer 70

only in the bladder

Question 71

what is an example of infectious ulceration

Answer 71

herpetic stomatitis

Question 72

what occurs in oral squamous cell carcinoma

Answer 72

dysplastic epithelial cells proliferate in an uncontrolled manner which destroyes and invades adjacent tissues