Lectures 4 and 5

Question 1

What is an epithelial junction?

Answer 1

How the epithelial cells attach to other cells, typically along the lateral border

Question 2

How are epithelial junctions classified?

Answer 2

By their function

Question 3

What are the 3 types of epithelial junctions?

Answer 3

Tight junctions, cytoskeletal linked junctions, and gap junctions

Question 4

Describe tight junctions.

Answer 4

Connect the luminal surface and seal neighboring cells, forming a cicumferential belt. (like the plastic around a 6 pack of cans)

Question 5

Describe cytoskeletal linked junctions.

Answer 5

bind cells together and to the basal lamina

Question 6

What are the 3 types of cytoskeletal linked junctions?

Answer 6

Adherent junctions, desmosomes (macul adherens), and hemidesmosome

Question 7

Describe adherent junctions.

Answer 7

forms a continuous adhesion belt near the apical surface, right below the tight junction

Question 8

Which types of epithelial junctions form continuous loops around cells?

Answer 8

tight and adherent

Question 9

What are cadherins?

Answer 9

plasma proteins that interact in the narrow space of an adherent juncion

Question 10

What anchors proteins in adherent junctions?

Answer 10

intermediate filaments

Question 11

What do the tight junction and adherent junction form together?

Answer 11

terminal bar

Question 12

Describe desmosomes (macula adherens).

Answer 12

They do not encircle the cell, more of a “spot weld,” they have extracellular filaments that span further to anchor the membranes, and they don’t have to be near the lateral luminal surface

Question 13

Which junction is the strongest?

Answer 13

desmosomes

Question 14

Describe hemidesmosomes.

Answer 14

half a desmosome used to anchor to the basal lamina

Question 15

Describe gap junctions.

Answer 15

Closely related membranes, but not fused, allowing low resistance channel of electrical and chemical communication

Question 16

What are the two apical border modifications?

Answer 16

microvilli and cilia

Question 17

What are finger-like projections on the cell surface?

Answer 17

microvilli

Question 18

What are hair-like projections on the cell surface?

Answer 18

cilia

Question 19

List the characteristics of microvilli.

Answer 19

actin filaments, short, numerous, increase surface area in absorptive epithelia, called the brush border or striated border, can be branched (uncommon, only in male repro tract)

Question 20

List the characteristics of cilia.

Answer 20

bundled microtubules, bigger, stronger, used for movement, parallel so they can beat together and move fluid over the surface, found in respiratory and repro tracts

Question 21

True or False:

Cells are commonly compartmentalized due to its surroundings, parts of the cell are only in one area.

Answer 21

true

Question 22

Epithelial junctions: cell to cell direct contact

Answer 22

tight junctions

Question 23

Epithelial junctions: junction with some filaments

Answer 23

adherent junctions

Question 24

Epithelial junctions: junction with many, crossing filaments

Answer 24

desmosome

Question 25

Epithelial junctions: junction that gets really close, but doesn't actually touch

Answer 25

gap junction

Question 26

Which junction types are found near the apical surface?

Answer 26

tight and adherent

Question 27

Which junction appears really dark?

Answer 27

desmosome

Question 28

Epithelial junctions: junction that is half crossing filaments, found on basal surface

Answer 28

hemidesomosome

Question 29

What are specialized epithelial cells modified into secretory structures that produces a variety of products for extracellular use?

Answer 29

glands

Question 30

What are the 2 ways to classify glands?

Answer 30

by the number of cells and the relationship to surround tissue

Question 31

What are 2 ways to classify number of cells?

Answer 31

unicellular and multicellular

Question 32

Describe unicellular glands

Answer 32

single secretory cell located in a non-secretory epithelium, scattered throught

Question 33

What is the most common unicellular gland?

Answer 33

goblet cells

Question 34

Where are goblet cells commonly found?

Answer 34

respiratory and GI tracts-they commonly secrete mucopolysaccharides

Question 35

Describe multicellular glands

Answer 35

an accumulation of specialized secretory cells, most glands will be this type

Question 36

What are the 2 relationships to surrounding tissue classifications?

Answer 36

endocrine glands and exocrine glands

Question 37

Describe endocrine glands.

Answer 37

DUCTLESS glands, dense vascular network, may have irregular clumps of cells, or cords of cells, or hollow follicles

Question 38

Describe exocrine glands.

Answer 38

DUCTS, maintain a communication, many different ways to classify

Question 39

What are the 3 ways to classify exocrine glands?

Answer 39

morphology, type of secretion, mode of secretion

Question 40

What are the 2 different types of morphology?

Answer 40

simple and compound

Question 41

What morphology has ducts that don't branch?

Answer 41

simple-usually microscopic and found within an organ

Question 42

What morphology has ducts that branch elaborately?

Answer 42

compound-usually discrete anatomic structures or organs themesleves

Question 43

What are the 4 types of secretion?

Answer 43

serous, mucous, mixed, and lipid

Question 44

Which type of secretion has watery secretion, stains relatively dark, nuclei are rounded near the base, apex is filled with secretory granules?

Answer 44

serous

Question 45

Which type of secretion has viscous secretion, nuclei flattened near the base, stains lightly?

Answer 45

mucous

Question 46

Which type of secretion has a combination of serous and mucous secretions?

Answer 46

mixed

Question 47

Which type of secretion has a lipid secretion?

Answer 47

lipid

Question 48

Which type of lipid secretions appears white with nuclei pushed to the edge of the cell?

Answer 48

common adipocyte

Question 49

Which type of lipid secretion appears as little white spots inside a fuscia stained cell?

Answer 49

multilocular

Question 50

What are the 4 modes of secretion?

Answer 50

merocrine, apocrine, holocrine, and cytocrine

Question 51

Describe merocrine secretion.

Answer 51

loses secretory product only by exocytosis, MOST COMMON

Question 52

Describe apocrine secretion.

Answer 52

apical portion of the cell is lost, membrane bound droplets and thin rims of cytoplasm and plasma membrane is released

Question 53

Describe holocrine secretion.

Answer 53

entire cell lost, extruded and constitutes the secretory product

Question 54

Describe cytocrine secretion.

Answer 54

transfer the secretory product to another cell or sheds the whole viable cells