Epithelial Tissue

Question 1

Give a quick overview of epithelial tissue - location, functions, classification, blood supply, types of cells, separated from CT

Answer 1

lines internal/external surfaces of body, has specialized functions (absorption, secretion, transport, protection), can be simple or stratified, avascular, polarized cells, separated by underlying CT by basement membrane

Question 2

simple squamous epithelium

Answer 2

lines blood vessels (endothelium), pleura, peritoneal and other serous cavities (mesothelium)

Question 3

stratified squamous non-keratinized epithelium

Answer 3

lines moist body surfaces (lie closest to lumen) - mouth, esophagus, vagina

Question 4

stratified squamous keratinized epithelium

Answer 4

skin!

Question 5

simple cuboidal epithelium

Answer 5

lines distal tubules in the kidney, follicles of thyroid gland, surface of ovary

Question 6

stratified cuboidal epithelium

Answer 6

lines the ducts of sweat glands (otherwise uncommon)

Question 7

simple columnar epithelium

Answer 7

lines stomach, intestine and excretory ducts of many glands

Question 8

stratified columnar epithelium

Answer 8

occasionally found in large excretory ducts of some glands and in cavernous urethra of penis (relatively uncommon)

Question 9

pseudostratified columnar epithelium - why is it pseudo? location? types of cells?

Answer 9

every cell rests on basal lamina but not all the cells reach the lumen - lines trachea, primary bronchi, excretory ducts in parotid gland, epididymis (with stereocilia) - may have muscous or goblet cells

Question 10

transitional epithelium

Answer 10

lines excretory passages in urinary sytem - from renal calyces to urethra

Question 11

hemidesmosomes

Answer 11

present along basal surface of cells - stratified squamous epithelia, myoepithelial cells in mammary and salivary glands, basal cells in tracheal epithelium.

Question 12

microvilli - structure and function

Answer 12

brush border, have a sugar coat, contain bundle of 30 actin filaments - absorption

Question 13

stereocilia - structure and function

Answer 13

not cilia, but long Mv, in epididymus and vas deferens, no motility - absorption

Question 14

cilia - structure

Answer 14

9 doublets + 2 single = axoneme

basal body - 9 triplets + 0

Question 15

endocrine glands - define, classification

Answer 15

secret into blood, no ducts - can be unicellular or multicellular

Question 16

exocrine gland - define, classification

Answer 16

have gland -
unicellular (goblet cell), multicellular [simple = no branch, compound = branch in duct]
acinar/alveolar = sac like
tubule = strait or coiled

Question 17

parotid gland

Answer 17

only serous units

Question 18

sublingual gland

Answer 18

both mucous and secretory units

Question 19

What is merocrine method of secretion?

Answer 19

exocytosis

Question 20

what is apocrine method of secretion?

Answer 20

part of the apical cytoplasm is release along with the secretory material

Question 21

what is holocrine method of secretion?

Answer 21

entire cell contents are released

Question 22

how do epithelial tissues get blood suppply since they are avascular?

Answer 22

diffusion of molecules through basal lamina

Question 23

what is zonula occuldens and what does it use?

Answer 23

its a tight junction

uses occudin

Question 24

what is zonula adherens and what does it use?

Answer 24

its a belt desmosome
uses E-cadherins
calcium
actin
viniculin

Question 25

what is macula adherens and what does it use?

Answer 25

its a demo some
uses dense plaques and desmoplaquins (intracellular proteins)
keratin
transmembrane linker
cadherin

Question 26

what do gap junctions use?

Answer 26

nexus, connexons = communicating junction

Question 27

what interlocks adjacent epithelial cells?

Answer 27

lateral interdigitations

Question 28

what makes up the basement membrane

Answer 28

basal lamina - lamina lucida, lamina rare +

reticular lamina

Question 29

what adheres cells to basement membrane? what do they use?

Answer 29

hemidesmosomes
use integrins
plauqe

Question 29

what adheres cells to basement membrane? what do they use?

Answer 29

hemidesmosomes
use integrins
plauqe