Epithelial Tissue

Question 1

Describe the functions of epithelia

Answer 1

line cavities and cover surfaces, separate 2 distinct domains while interacting with the contents of each domain

Question 2

Describe the characteristics of epithelial cells

Answer 2

tightly packed together, form avascular sheets, attached to a basement membrane, sit on underlying connective tissue, have polarity (apical and basal regions)

Question 3

Name the two kinds of apical surface modifications

Answer 3

microvilli, cilia

Question 4

Function of microvilli?

Answer 4

to increase surface area of hte cell

Question 5

Microvilli have what kind of filaments to give them structure and anchor?

Answer 5

Actin filaments

Question 6

Function of cilia?

Answer 6

move fluid and particles along epithelial surfaces

Question 7

Cilia have what to give them structure?

Answer 7

Microtubules

Question 8

What anchors cilium to the cytoskeleton?

Answer 8

Basal body

Question 9

3 kinds of lateral surface modifications?

Answer 9

occluding junctions, anchoring junctions, communicating junctions

Question 10

Describe occluding junctions

Answer 10

tight junctions, seal membranes together

Question 11

Occluding junctions are formed by what two transmembrane proteins

Answer 11

occluding, claudin

Question 12

Describe anchoring junctions

Answer 12

zonula adherens provide lateral adhesion (hold cells together); macula adherens = desmosome, spotlike junction

Question 13

Zonula adherens consist of what 2 proteins? that link to?

Answer 13

Cadherins, integrins; actin filaments of cytoskeleton

Question 14

Describe communicating junctions?

Answer 14

Gap junctions permit passage of molecules

Question 15

gap junctions are made of what protein family?

Answer 15

Connexin proteins - make connexons (pores that can be open or closed)

Question 16

Name the 2 areas of the basement membrane

Answer 16

Basal lamina (directly below epithelial cells); reticular lamina below basal lamina

Question 17

Name the 2 anchoring junctions on the basal surface

Answer 17

Hemidesmosome and focal adhesions

Question 18

Describe focal adhesions on the basal surface

Answer 18

anchor the cell’s internal actin to basal lamina; use integrins (transmembrane proteins) to detect/transduce signals

Question 19

Transitional epithelium has what special cells on the apical surface

Answer 19

dome cells (or umbrella cells)

Question 20

Simple squamous function

Answer 20

thin barrier for exchange, frictionless movement of fluids and/or organs

Question 21

Simple cuboidal function

Answer 21

line a conduit, can absorb and/or secrete materials

Question 22

Simple columnar function

Answer 22

absorption and/or secretion

Question 23

Stratified squamous keratinized function

Answer 23

protection of dry areas

Question 24

Stratified squamous nonkeratinized function

Answer 24

protection of moist areas

Question 25

Stratified columnar function

Answer 25

barrier, conduit

Question 26

Pseudostratified columnar function

Answer 26

secretion, conduit in resp. tract and epididymis; move mucus, absorption,

Question 27

Transitional function

Answer 27

barrier in chambers and tubes that distend