Lecture 30 11/7/23

Question 1

How does epithelia function in protection?

Answer 1

-covering external surfaces
-lining internal surfaces

Question 2

What are the secretory functions of epithelia?

Answer 2

producing:
-mucus
-gastric and pancreatic juices
-saliva
-“sweat”

Question 3

Where does epithelia have absorptive function?

Answer 3

-intestines
-renal tubules

Question 4

Which epithelium has sensory function?

Answer 4

olfactory epithelium

Question 5

What are the transport functions of epithelia?

Answer 5

-movement of water/ions through and around cells
-movement of substances across surfaces

Question 6

What are the special functions of epithelia?

Answer 6

-gas exchange
-gliding between surfaces

Question 7

What are the features of epithelia?

Answer 7

-polygonal
-polar
-relatively avascular
-almost wholly cellular (very little connective tissue/extra space)
-cell-to-cell junctions
-bound to basement membrane through hemidesmosomes

Question 8

How does the epithelia get blood if it is primarily avascular?

Answer 8

diffusion from local vessels

Question 9

What are the types of junctions between cells?

Answer 9

-tight junctions
-zonula adherens
-macula adherens/desmosomes

Question 10

What is the shape of squamous cells?

Answer 10

flat

Question 11

What is the shape of cuboidal cells?

Answer 11

cubed, same width as height

Question 12

What is the shape of columnar cells?

Answer 12

taller than wide

Question 13

What is simple epithelia?

Answer 13

epithelia in a single layer

Question 14

What is stratified epithelia?

Answer 14

epithelia in more than one layer

Question 15

How is stratified epithelia named when the cell types change throughout?

Answer 15

based on the shape of the surface layer cells

Question 16

what is pseudo-stratified epithelia?

Answer 16

-single layer that looks like multiple
-typically columnar

Question 17

Which types of epithelia have all cells touching the basement membrane?

Answer 17

-simple
-pseudostratified

Question 18

What are the characteristics of microvilli?

Answer 18

-short
-non-motile
-increased surface area for absorption

Question 19

What are the characteristics of cilia?

Answer 19

-long
-motile
-aid in clearance

Question 20

Where are microvilli found?

Answer 20

simple or pseudo-stratified epithelium

Question 21

Where are microvilli of importance?

Answer 21

-intestinal brush border
-proximal convoluted tubules of kidney

Question 22

Where are cilia found?

Answer 22

simple or pseudo-stratified epithelium

Question 23

What is respiratory epithelium?

Answer 23

pseudostratified ciliated columnar epithelium +/- goblet cells

Question 24

What are the characteristics of stereocilia?

Answer 24

-long microvilli
-non-motile

Question 25

Where are stereocilia found?

Answer 25

-hair cells of the ear -male repro. tract

Question 26

What are the characteristics of goblet cells?

Answer 26

-modified columnar cells -produce mucus

Question 27

Where will simple squamous epithelium be found?

Answer 27

-lining cardiovascular system -lining body cavities -lining posterior surface of cornea -glomerulus of kidney -alveoli of lungs

Question 28

What does simple squamous epithelium look like?

Answer 28

single layer of flattened nuclei w/ little cytoplasm

Question 29

What are the roles of simple squamous epithelium?

Answer 29

-allowing things to glide by -allowing for movement through a barrier

Question 30

What is the role of stratified squamous epithelium?

Answer 30

very tough, so found at high friction sites

Question 31

Where is stratified squamous epithelium found?

Answer 31

-oral cav. -pharynx -esophagus -anal canal -uterine cervix -vagina -anterior cornea

Question 32

What is keratinized stratified squamous epithelium?

Answer 32

-cells die and leave behind tough dead "skeletons" filled with keratin -makes surface resistant to friction and drying out

Question 33

Where is keratinized squamous epithelium found?

Answer 33

-skin/footpads -oral cav. -forestomachs of herbivores

Question 34

How do orthokeratosis and parakeratosis differ?

Answer 34

-orthokeratosis has no cell nuclei in the keratin layer -parakeratosis does have cell nuclei in keratin layer

Question 35

What are the roles of simple cuboidal epithelium?

Answer 35

-tougher than simple squamous; found in duct linings -transport/absorption at kidney tubules -comprises apocrine gland

Question 36

Where is stratified cuboidal epithelium seen?

Answer 36

excretory ducts (apocrine and salivary glands)

Question 37

What are the roles of simple columnar epithelium?

Answer 37

-tougher than cuboidal -protection -absorption -transport -sensory

Question 38

Where is simple columnar epithelium found?

Answer 38

-GI tract -gall bladder -repro. tract -nose

Question 39

What does simple columnar epithelium look like?

Answer 39

-tall rectangles -nucleus near bottom of cell

Question 40

Where is stratified columnar epithelium seen?

Answer 40

-conjunctiva -salivary gland ducts

Question 41

What are the characteristics of transitional epithelium?

Answer 41

-surface layers transition between squamous and cuboidal -only found in urinary tract/called urothelium -accommodates stretching of urinary bladder -withstands "irritation" of urine