Epithelium

Question 1

occluding junctions are also called

Answer 1

tight junctions, or Zonula Occludens

Question 2

occluding junctions forms a ring or circumferential band around the cell

Answer 2

serves as a diffusion barrier

Question 3

outer leaflets of adjoining plasma membrane fuse

Answer 3

fusion occurs in band or belt like configuration around cell

Question 4

the tight junction seal is created by two transmembrane proteins

Answer 4

occludins, and claudins, form a zipper seal

Question 5

zonula occludens proteins

Answer 5

ZO-1, ZO-2, ZO-3

Question 6

zonula occludens proteins interact with cytoskeleton actin filaments

Question 7

ZO-1 and ZO-2 proteins are vulnerable for toxins and pathogenic virus

Answer 7

example is Cholera toxin, cytomegalovirus, dengue virus

Question 8

Toxins produced by helicobacter pylori damage the occluding junctions of the gastric mucosa and cause leaking of HCL in stomach wall

Answer 8

leads to bleeding and peptic ulcers

Question 9

blood brain barrier

Answer 9

occluding junction that prevents proteins in the circulating blood entering nerve tissue

Question 10

zonula occludens restrict movement of lipid rafts

Question 11

functions of zonula occludens

Answer 11

prevents molecules crossing the epithelium, prevent a paracellular pathway

Question 12

functions of zonula occludens

Answer 12

restrict movements of membrane lipids and proteins at the apical domain into the lateral and basal domains

Question 13

functions of zonula occludens

Answer 13

maintain two distinct membrane domains- Apical, and basolateral

Question 14

Anchoring junctions have two types

Answer 14

zonula adherens and macula adherens (desmosome)

Question 15

zonula adherens are

Answer 15

continuous band like adhesion

Question 16

macula adherens or Desmosomes

Answer 16

localized spot adhesion

Question 17

zonula adherens are formed by

Answer 17

binding of transmembrane proteins E-cadherins (epithelial cadherins) of neighboring cells

Question 18

zonula adherens are calcium dependent

Question 19

macula adherens or desmosomes

Answer 19

provide strong attachment to cells

Question 20

macula adherens contains large proteins of the cadherin family such as

Answer 20

desmogleins, desmocollins

Question 21

macula adherens have cytoplasmic ends of the proteins bind with plakoglobins

Answer 21

plakoglobins bind with desmoplakins

Question 22

gap junctions or nexuses

Answer 22

channels on the lateral surface of adjoining cells

Question 23

gap junctions

Answer 23

allow direct passage of signaling molecules from one cell to another

Question 24

gap junctions consist of transmembrane channels called

Answer 24

connexons

Question 25

connexons are made up of

Answer 25

six connexin proteins

Question 26

connexons on one cell membrane precisely align with corresponding connexons that allow

Answer 26

communication between cells and exchange of ions

Question 27

anchoring junctions attach cell to extracellular matrix by two types

Answer 27

Hemidesmosomes and focal adhesions

Question 28

hemidesmosomes are

Answer 28

half desmosome located on the basal surface of cell

Question 29

hemidesmosomes - TEM exhibits intracellular attachment plaques on cytoplasmic side of plasma membrane

Question 30

Hemidesmosomes Attachment plaques are composed of desmoplakins such as

Answer 30

plectin, erbin, BP 230

Question 31

Hemidesmosomes attachment plaques are attached to basal lamina by transmembrane proteins :

Answer 31

integrins, BP 180 or type XVII collagen (also known as anchoring filaments)

Question 32

Bullos Pemphigold

Answer 32

rare autoimmune skin condition-high levels of antibodies are formed against BP230 and or BP180 Absence of the functional BP230 causes blistering of the skin (fluid build up between epidermis and dermis)

Question 33

focal adhesions

Answer 33

connect the cytoskeleton to the extracellular matrix by linking actin filaments to the extracellular matrix protiens

Question 34

focal adhesions consist of 3 faces

Answer 34

cytoplasmic face- actin filaments transmembrane face- integrins extracellular face-laminin and fibronectin

Question 35

epithelial glands form during development by proliferation of epithelial cells

Question 36

Some Epithelial glands retain their continuity witht the surface via a duct

Answer 36

Exocrine glands

Question 37

Some epithelial glands lose this direct continuitity with the surface when their ducts degenerate...

Answer 37

Endocrine Glands

Question 38

Endocrine glands discharge secrete into blood system

Question 39

exocrine gland can be unicellular

Answer 39

goblet cells

Question 40

exocrine glands can be multicellular, secretions are delivered into ducts

Answer 40

sweat glands

Question 41

Endocrine glands

Answer 41

glands without ducts, secretions are released into blood stream

Question 42

Unicellular Exocrine glands

Answer 42

release products from epithelial cells

Question 43

goblet cells

Answer 43

unicellular exocrine gland, synthesize and secrete mucus essential role in maintaining protective mucosal barrier

Question 44

In ulcerative colitis, goblet cell number and size drastically decrease

Question 45

Multicellular Exocrine Glands-two features of morphological classification

Answer 45

duct structure and shape of secretory unit

Question 46

Multicellular exocrine glands-based on duct structure

Answer 46

simple-single branched duct, large intestine glands compound-branched duct, ex salivary glands

Question 47

Multicellular exocrine glands are based on shape of secretory units

Answer 47

tubular or aveolar- example of sweat glands acinar- rounded and saclike-salivary glands

Question 48

merocrine gland is most

Answer 48

common type of secretion

Question 49

Classification of Multicellular exocrine glands

Answer 49

Merocrine, holocrine, apocrine

Question 50

Merocrine classification

Answer 50

most common type Secretion is released by exocytosis example sweat gland

Question 51

Holocrine classification

Answer 51

whole cell ruptures during release of product ex. sebaceous gland

Question 52

Apocrine classification

Answer 52

Apical cytoplasm is lost with the secretion example of mammary gland

Question 53

Multicellular exocrine glands classification

Answer 53

Serous, mucous, mixed (serous and mucous secretion)

Question 54

Mucous Membrane or mucosa

Answer 54

lines cavities that connect with outside of body example GIT, respiratory ducts, urogenital tract consists of: diverse types of epithelium, basal lamina, and lamina propria May contain glands that secrete mucus

Question 55

serous membrane of serosa

Answer 55

lines closed cavities-peritoneal, pleural, pericardial cavities consists of : simple squamous, mesothelium, basal lamina, and underlying this loose connective tissue DOES NOT contain glands Two components: Parietal and Visceral

Question 56

Parietal serous membrane lines

Answer 56

body cavity

Question 57

Visceral serous membrane covers

Answer 57

organs in the body cavity

Question 58

parenchyma

Answer 58

functional tissue of an organ as distinguished from the connective and supporting tissue

Question 59

stroma

Answer 59

supporting connective tissue with blood vessels and nerve fibers

Question 60

list differences between serous glands, mucous glands, and mixed glands