Hovorka-Epithelium and Glands

Question 1

what are the major functions of epithelial tissues?

Answer 1

secretion, absorption, transport, protection, receive external stimuli (retina, tongue, inner ear, smell)

Question 2

what are the typical locations of epithelial tissues?

Answer 2

covering surfaces, lining cavities, forming the secretory portion of glands and their ducts

Question 3

characteristics of epithelial tissues?

Answer 3

strong cell adhesions, apical surface faces a lumen, avascular, attached to basement membrane

Question 4

what type of epithelium has a single layer?

Answer 4

simple layer

Question 5

what type of epithelium has 2 or more layers?

Answer 5

stratified

Question 6

what shape are flat cells?

Answer 6

squamous

Question 7

what shape are cube cells?

Answer 7

cuboidal

Question 8

what type of cell is taller than they are in width?

Answer 8

columnar

Question 9

what type of cell may appear cuboidal when relaxed but when stretched appears squamous?

Answer 9

transitional cells (important for the urine collection system)

Question 10

what part of the cell is modified in brush border, sterocilia and cilia?

Answer 10

apical modification

Question 11

what does the endothelium line?

Answer 11

simple squamous epithelium that lines blood vessels

Question 12

what does mesothelium line?

Answer 12

simple squamous epithelium that lines body cavities

Question 13

how are microvilli usually arranged and what is there purpose?

Answer 13

packed microvilli form a brush border and they are important for absorption

Question 14

what is another name for extra-long microvilli?

Answer 14

stereocilia

Question 15

what is the function of cilia?

Answer 15

move substances

Question 16

in what domain do cell to cell junctions form?

Answer 16

lateral domains

Question 17

name the three lateral domain junctions.

Answer 17

occluding, anchoring and communicating

Question 18

what is the function of occluding junctions?

Answer 18

prevent membrane proteins from moving between the apical and lateral domains (barriers)

Question 19

what are the two types of anchoring junctions?

Answer 19

zonula adherens and desmosomes

Question 20

what are zonula adherens?

Answer 20

belt-like junctions that interact with the actin cytoskeleton

Question 21

what are desmosomes?

Answer 21

(macula adherens) “spot weld” type junctions that interact with the intermediate filament cytoskeleton of the cell.

Question 22

what are communicating junctions?

Answer 22

(gap junctions) create a conduit thru which ions and small molecules can freely diffuse between the cytoplasm of adjacent cells.

Question 23

name the two major types of basal domain adhesions.

Answer 23

focal adhesions

hemidesmosomes

Question 24

what do focal adhesions attach too?

Answer 24

these junctions attach the actin cytoskeleton to the extracellular matrix

Question 25

what do hemidesmosomes attach too?

Answer 25

attach the intermediate filament cytoskeleton to the ECM.

Question 26

what is the basal lamina (closest to the epithelium) composed of?

Answer 26

type IV collagen, laminin, proteoglycans and glycoproteins

Question 27

what type of stain is best to visualize the basal lamina?

Answer 27

best visualized with PAS stain due to the carbohydrates of the proteoglycans and glycoproteins

Question 28

what are the layers of the basal lamina?

Answer 28

lamina densa (filament layer) and lamina rara (clear layer)

Question 29

what the third possible layer of the basement membrane that some cells contain?

Answer 29

reticular layer (separate from basal lamina)

Question 30

how are glands formed?

Answer 30

invagination of epithelial tissue

Question 31

how do exocrine glands secrete their products?

Answer 31

secrete their products onto a surface, either directly or thru ducts

Question 32

what are three types of glands?

Answer 32

merocrine, apocrine and holocrine

Question 33

how are the contents of merocrine glands secreted?

Answer 33

product is released when vesicle fuses with the plasma membrane at the apical surface of the cell (exocytosis)

Question 34

how are the contents of holocrine glands secreted?

Answer 34

the product accumulates in the cell and when the cell undergoes apoptosis the content is released in lumen

Question 35

how are the contents of apocrine glands secreted?

Answer 35

they bud off from the apical plasma membrane. since budding occurs the plasma membrane must be regenerated in the cell

Question 36

how do products of endocrine glands travel?

Answer 36

the secreted hormones travel via the bloodstream to target tissue

Question 37

how are exocrine glands further divided?

Answer 37

serous, mucus, seromucus

Question 38

what type of cell has a well developed rough ER and secretion that is thin, watery and protein rich?

Answer 38

serous

Question 39

what is the texture of mucus and what is unique about its small protein core.

Answer 39

viscous, and it contains negatively-charged carbohydrates

Question 40

what is unique about seromucus glands?

Answer 40

mucus secreting cells along the tubular portion that is capped by serous secreting cells

Question 41

what type of glands make up ducts?

Answer 41

multicellular glands

Question 42

what term describes branching ducts?

Answer 42

compound

Question 43

is it true that multiple glands leading to one duct is considered branched?

Answer 43

yes

Question 44

are alveolar (acinar) shaped long tubes?

Answer 44

no. they form bulb shapes