Lecture 3: Epithelial Tissues

Question 1

side of cell that faces the external environment

Answer 1

apical domain

Question 2

side of cell that is in contact with neighbor cells

Answer 2

basolateral domain

Question 3

side of cell in contact with the basal lamina

Answer 3

basal domain

Question 4

what are the 3 germ layers epithelial tissues are derived from?

Answer 4

ectoderm
endoderm
mesoderm

Question 5

ectoderm

Answer 5

epidermis and glands

Question 6

endoderm

Answer 6

lining of GI tract and glands

Question 7

mesoderm

Answer 7

lining of blood vessels

Question 8

epithelial tissues rest upon a _____ .

Answer 8

basement membrane

Question 9

components of the BM

Answer 9

basal lamina

reticular lamina

Question 10

BM layer next to epithelial layer

Answer 10

basal lamina
composed of type IV collagen and glycoproteins
PAS+

Question 11

BM layer not next to the epithelial layer

Answer 11

reticular lamina
in contact with underlying CT
composed of: argyrophilic fibers, reticular fibers, glycoproteins

Question 12

functions of the BM

Answer 12

selective filtration barrier
scaffolding for genesis and regeneration
stabilize tissue shape

Question 13

simple vs. stratified

Answer 13

one vs. more than one layers

Question 14

shapes of epithelial cells

Answer 14

squamous — flattened
cuboidal —- height = width
columnar —- height > width

Question 15

special categories of epithelia

Answer 15

pseudostratified

transitional

Question 16

other name for transitional epithelium

Answer 16

urothelium

Question 17

what makes urothelium special?

Answer 17

changes shape depending upon volume within cavity

all cells are in contact with basal lamina

Question 18

what makes pseudostratified special?

Answer 18

appears stratified but all calls are in contract with basal lamina
nuclei are at different height
lower = stem cells

Question 19

surface modifications

Answer 19

cilia
stereocilia
microvilli

Question 20

lightly keratinized

Answer 20

vagina

esophagus

Question 21

heavily keratinized

Answer 21

skin

Question 22

what does it mean to be keratinized?

Answer 22

cells are dead
have no organelles or nucleus
are filled with the protein keratin

Question 23

keratin is responsible for making our skin ______ .

Answer 23

waterproof

Question 24

which domains of epithelial cells have surface modifications?

Answer 24

apical domain

Question 25

junctions between basolateral domains

Answer 25

tight junctions --- seals no extracellular matrix keeps cells together and create barriers can be leaky or tight barriers

Question 26

brush border

Answer 26

microvilli

Question 27

finger like projections

Answer 27

cilia

Question 28

finger like projections that are non-motile

Answer 28

stereocilia longer than cilia and can be branched

Question 29

simple squamous locations

Answer 29

lining of ducts, vessels, tubular structures walls of alveoli inner surface of membranes tympanic membrane

Question 30

simple cuboidal locations

Answer 30

kidney tubules ovary surface glands and ducts

Question 31

simple columnar locations

Answer 31

``` intestinal cells upper respiratory tract uterine tubes uterus digestive tract ```

Question 32

stratified squamous locations

Answer 32

keratinized - skin, cornea | light/non - esophagus, vagina, mouth lining, tongue, epiglottis

Question 33

stratified cuboidal locations

Answer 33

very rare anal mucosa male urethra large excretory ducts

Question 34

stratified columnar locations

Answer 34

``` very rare ducts of sweat glands whites of the eye male reproductive/urinary tract pharynx epiglottis ```

Question 35

pseudostratified locations

Answer 35

trachea | epididymis

Question 36

transitional locations

Answer 36

urinary system

Question 37

types of epithelium involved in secretion and absorption

Answer 37

simple or pseudostratified epithelium | simple columnar

Question 38

microvilli properties

Answer 38

non-motile brush border | supported by cross-linked actin bundles

Question 39

microvilli function

Answer 39

to increase surface area of absorption

Question 40

microvilli locations

Answer 40

intestinal epithelium | renal tubules

Question 41

microvilli structure

Answer 41

actin filament core | formin cap on distal end of actin filaments

Question 42

microvilli core properties

Answer 42

extends into terminal web of cytoskeleton | core filaments are cross-linked by villin and fimbrin

Question 43

cilia structure

Answer 43

9 peripheral doublets | central pair of microtubules

Question 44

cilia doublets

Answer 44

consists of an alpha and beta tubules

Question 45

alpha tubule

Answer 45

of the cilia doublet contains: 13 protofilaments radial spokes that extend to sheath around central pair spokes help anchor the tubule pairs of dynein arms that extend to neighbor tubule's beta unit

Question 46

beta tubule

Answer 46

of the cilia doublet smaller than the alpha and only half a circle 10-11 protofilaments

Question 47

cilia functions

Answer 47

either move mucous back and forth or move the cell not surround material