Hovorka-Epithelium and Glands Flashcards Preview

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Flashcards in Hovorka-Epithelium and Glands Deck (44):
1

what are the major functions of epithelial tissues?

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

2

what are the typical locations of epithelial tissues?

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

3

characteristics of epithelial tissues?

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

4

what type of epithelium has a single layer?

simple layer

5

what type of epithelium has 2 or more layers?

stratified

6

what shape are flat cells?

squamous

7

what shape are cube cells?

cuboidal

8

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

columnar

9

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

transitional cells (important for the urine collection system)

10

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

apical modification

11

what does the endothelium line?

simple squamous epithelium that lines blood vessels

12

what does mesothelium line?

simple squamous epithelium that lines body cavities

13

how are microvilli usually arranged and what is there purpose?

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

14

what is another name for extra-long microvilli?

stereocilia

15

what is the function of cilia?

move substances

16

in what domain do cell to cell junctions form?

lateral domains

17

name the three lateral domain junctions.

occluding, anchoring and communicating

18

what is the function of occluding junctions?

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

19

what are the two types of anchoring junctions?

zonula adherens and desmosomes

20

what are zonula adherens?

belt-like junctions that interact with the actin cytoskeleton

21

what are desmosomes?

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

22

what are communicating junctions?

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

23

name the two major types of basal domain adhesions.

focal adhesions
hemidesmosomes

24

what do focal adhesions attach too?

these junctions attach the actin cytoskeleton to the extracellular matrix

25

what do hemidesmosomes attach too?

attach the intermediate filament cytoskeleton to the ECM.

26

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

type IV collagen, laminin, proteoglycans and glycoproteins

27

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

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

28

what are the layers of the basal lamina?

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

29

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

reticular layer (separate from basal lamina)

30

how are glands formed?

invagination of epithelial tissue

31

how do exocrine glands secrete their products?

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

32

what are three types of glands?

merocrine, apocrine and holocrine

33

how are the contents of merocrine glands secreted?

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

34

how are the contents of holocrine glands secreted?

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

35

how are the contents of apocrine glands secreted?

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

36

how do products of endocrine glands travel?

the secreted hormones travel via the bloodstream to target tissue

37

how are exocrine glands further divided?

serous, mucus, seromucus

38

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

serous

39

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

viscous, and it contains negatively-charged carbohydrates

40

what is unique about seromucus glands?

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

41

what type of glands make up ducts?

multicellular glands

42

what term describes branching ducts?

compound

43

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

yes

44

are alveolar (acinar) shaped long tubes?

no. they form bulb shapes