Week 4 Basal and Lateral Domain of Epithelium Module Flashcards Preview

Foundations 1 > Week 4 Basal and Lateral Domain of Epithelium Module > Flashcards

Flashcards in Week 4 Basal and Lateral Domain of Epithelium Module Deck (36)
Loading flashcards...
1
Q

how many types of epithelial junctions are there? where are they located?

A

5 total. 4 in lateral domain. 1 in basal domain

2
Q

what are the two general roles of epithelial junctions

A

cellular adhesion, cellular communication

3
Q

what are the 4 major families of cell adhesion molecules (CAMs)

A

cadherins, integrins, immunoglobulin super family, selectins

4
Q

which CAMs are responsible for epithelial cell jxns?

A

cadherins and integrins

5
Q

which CAMs play a role in inflammation?

A

IGSF and selectins

6
Q

what is the general structure of cadherins and integrins

A

transmembrane proteins with extracellular binding domains

7
Q

Cadherin: type seen in epithelial cell? Calcium? Interactions in the intracellular domain? role?cancer?

A

E- cadherin seen in epithelial cells Ca dependent extracelular domain (CA dependent ADHERINs) associated with catenins that link the adherin to the actin cytoskeleton important in cell-cell connections; cell recognition, tumor suppresssion cancer cells lose cadherin molecules and are able to metastasize

8
Q

Intergrins: strucutre? Calcium? role 3?

A

heterodimer: alpha and beta chains calcium independent cell-cell, cell-ECM binding, facilitates cell movement in ECM

9
Q

what are the four types of cell jxns found in the lateral domain of epithelial cells?

A

zonula occludens (tight jxn), zonula adherens (intermediate jxns), macula adherens (desmosomes), gap jxn

10
Q

what is the general location of zona occludens?

A

this is the most apical jxn

11
Q

what is the general location of zona adherens

A

just beneath the Zona occludens

12
Q

where are macula adherens found on the lateral domain of epithelial cells?

A

erratically. desmosomes are sometimes termed “spot welds”. below zona adherens (more towards basal surface)

13
Q

what is the role of gap junctions?

A

permit direct passage of signaling molecules from one cell to another

14
Q

what is the role of Zonula occludens?

A

tight jxns. forms a barrier that prevents paracellular transport (transport between cells). separates apical domain from the basal and lateral domain

15
Q

what are two proteins associated with zonula occludens?

A

occludin and claudin

16
Q

what is the function of zonula adherens?

A

intermediate junctions. anchor cells to each other through actin filaments within the cell attached to cadherin and catenins

17
Q

what is the funciton of macula adherens?

A

desmosomes: spot welds between epithelial cells that resist shear force.

18
Q

what proteins are associated with macula adherens? 4

A

desmoglein, desmocolin (cadherin), desmoplakin, plakoglobin

19
Q

given the fxn of macula adherins, where would we expect to see them in the most abundance?

A

stratified squamous epithelium (skin’s epidermis) where cells must resist a lot of friction

20
Q

gap junctions are made of ____ which form____

A

connexin which forms connexon

21
Q

what is the overall function of the basal domain

A

anchors epithelium to the Basement membrane

22
Q

what are the two regions of the basement membrane

A

basal lamina (more superficial; interfaces with connective tissue and epithelial cells) and reticular lamina (more deep)

23
Q

what is the clinical significance of the basal lamina

A

penetration of the basal lamina indiacates a tumor is undergoing malignant progression and is capable of metastasis

24
Q

what is the role of focal adhesions? 2

A

link network of cytoplasmic actin filaments to basal lamina proteins (attach cell to ECM), signal transduction from ECM to cell

25
Q

focal adhesions are made of ____ and bind to ___3__ in the basal lamina

A

integrins. fibronectin, collagen, laminin

26
Q

what is the role of hemidesmosomes?

A

anchor the basal plasma membrane to the basal lamina

27
Q

what are the 2 important structures you should associate with hemidesmosomes

A

BP230, basement membrane

28
Q

Pemphigus vulgaris: what type of jxn is affected? how? which domains are lost? where/what type of blister?

A

desmosomes are lost: cell attachement to each other are lost, but basal domain remains. body creates antibodies against desmogleins 1 and 3. flaccid blisters occur in the epidermis

29
Q

what is Nikolsky’s sign?

A

a test where a pencil eraser is twirled on the skin, if a blister develops it is a postive test for a blistering skin condition

30
Q

Bulous Pemphigoid: what type of jxn affected? how? which domains are lost? what type of blister?

A

body produces antibodies against BP230 and destroy hemidesmosomes. cells lose basal domain connection but keep lateral domain. tense blister

31
Q

Blisters: what are they, where do they form? what types?

A

Clear area filled with leukocytes and fibrin, form between intact epidermis and the dermis. Flaccid=easy to rupture, Tense=difficult to rupture

32
Q

what causes dystrophic epidermolysis bullosa? why is this a problem?

A

inherited defect in collagen VII. collagen VII plays a role in holding the BM to the underlying connective tissue. epidermis with attached BM comes off surface. Epidermis+BM shears right off (loss of dermal-epidermal jxn).

33
Q

does dystrophic epidermolysis bullosa impact anything other than skin? why?

A

yes. Collagen VII is important in stratified squamous epithelium which is also seen in the esophagus.

34
Q
A

Dystrophic Epidermolysis Bullosa

35
Q
A

Bullous Pemphigoid

36
Q
A

Pemphigus Vulgaris

Decks in Foundations 1 Class (65):