Epithelium: Apical Differentiations and CAM Flashcards Preview

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Flashcards in Epithelium: Apical Differentiations and CAM Deck (55):
1

Kinocilium

a type of primary cilia that is part of the organ or corti in the inner ear

2

What lines the oviduct?

ciliated epithelial cells

3

Clijum is made up of..

microtubules

4

microvilli are made up of

microfiliments

5

sterocillium are made up of

microfiliments

6

Paracellular pathway

between cells

7

transcellular pathway

through cells

8

basal lamina is made up off

type 4 collagen +laminin

9

the reticular lamina is made up of

collagens, fibronectin, proteoglycans

10

Cadherins have how many calcium domains?

4

11

What sequence on the Cadherin facilitates cis-homophillic dimer formation

HVA (histadine-valine-alanine)

12

What are the three actin binding proteins on Cadherins?

Vinculin, formin-1, alpha actinin (catinins)

13

Name calcium dependent CAM?

Cadherin and Selectin

14

Name Calcium independent CAM?

IgSF and Integrins

15

E-cadherin is found in..

epithelia

16

N-cadherin is found in...

CNS, lens of the eye, cardiac and skeletal muscle

17

P-Cadherin is found in...

placenta (tropoblast)

18

Removal of Calcium disrupts...

tissue cohesiveness

19

What CAMS bind to F-Actin?

Cadherins and Integrins

20

What are the actin binding proteins for integrins?

Vinculin, talin, alpha actinin

21

beta catinin is also seen as a

transcriptional cofactor....colorectal carcingenisis

22

What are the three distinct apical differentiations?

Cilia
Microvilli
Sterocilia

23

Selectins

Carbohydrate recognizing domain

24

What alters the carbohydrate recognizing domain in Selectins?

Calcium bound at the sides of the CRD regulates the conformation of the domain and its ability to bind carbohydrates

25

What CAMs play a part in homing?

Selectins
Integrins attached to ICAM

26

Selectins mediate interactions between what...

leukocytes and endothelial cells or blood platlets

(intiate interactions between leukoctes from circulation to the sites of tissue inflammation)

27

E-selectin

Activated endothelial cells (blood vessels)

28

L-selectin

leukocytes

29

P-selectin

platelets and activated endothelial cells lining blood vessels (stored inc ytoplasmic vesicles in endothelial cells)

**on surface leukocytes have sialyl lewis-x antigen(olgiosaccride ligand for P-selectin)
slow down leukocytes

30

Homing (describe process)

1. Selectins mediate initial adhesion of leukocytes to endothelial cells
2. formation of more stable adhesions in which integrins (on surface of leukoytes) bind to intracellular adhesion molecules (ICAMS, IgSF)
3. The firmly attached leukocytes penetrate hte walls of cpaillaries and enter the tissue by migrating between endothelial cells (transcellular pathway) Transendothelial migration

31

What are the main adhesion proteins holding peithelial cells together?

Cadherins
Sheet arrangement

32

Which part of the Cadherin interacts wiht F-actin

The cytoplasmic Tail
through catinins

33

What catinin directly binds to Cadherin

beta

34

What catinin directly binds to actin

alpha

35

Selectins have how many extra cellular domains?

three

36

What are the three main domains of Selectins?

1. Carbohydrate recognition domain (olgiosaccrides when attached to protien glycoprotein.. when attached to lipid glycolipid)
2. Epidermal Growth Factor like domain
3. Consenus repeats

37

IgSf (immunoglobulin superfamily)

Immunoglobin domain/fold
Calcium independent
extracellular domain adhesion molecule
trans heterophillic/homphillic bidning

38

Different types of IgSf

NCAM-neural tissues/nerve cells
VCAM-endothelial cells
ICAM-btwn leukocytes and endothelial cells (integrins on the surface of leukocytes bind to ICAMS) more stable adhesion

39

CAMS Important in T cell interactions and binding of leukocytes to activated or resting endothelial cells

I CAM
V CAM

40

IgSf

Encoded by a single gene
alternative mRNA

41

What is the receptor for HIV-1 (tcells/helper cells)

IgSF (CD4)

42

Integrins

heterodimers (alpha and beta subunits)

43

Do Integrins have cytoplasmic or extracellular Domain?

CYTOPLASMIC DOMAIN

44

What links integrins to actin?

Connecting Protiens (Vinculin, Talin, alpha actinin)

45

What sequence do integrins recognize?

RGD sequence found in fibronectinin and laminin

46

What subunit recognizes the RGD sequence?

the beta subunit

47

What regulates the beta subunit binding in integrins?

the alpha subunit

48

What links the cytoskeleton to the ECM?

integrins

49

Laminin is found where?

in basal lamina
made by epithelial cells

50

Fibronectin is found where?

in recticular lamina
made by fibroblast

51

In hemidesmosomes integrins link...

basal lamina to intermediate filaments
**which link the basal domain to the basement membrane**

52

Steps of Homing

1. rolling: L-selectin
2. adhesion: integrin activation (trigged by inflamm substances...chemokines)
3. Transendothelial migration (diapedesis) involves f actin and myosin

53

Purpose of Homing

to help with the moment of leukocytes from the blood stream to their home ( lymph nodes and thymus) or connective tissue

54

Adam Proteins
( A Disintegrin A metalloprotease)

reversal of integrin mediated cell binding to ECM disrupted by
needs zinc for proteolytic activity

55

Adam Protein Domains (3)

1. disintegrin domain (snake venom)
has RGD tripeptide which binds to platelet glycoprotien gpIIb/IIA
prevents platelet aggregation

2. metalloprotease domain
degrades components of ECM during migration + cleavage of membrane protein at plasma level release of soluble ectodomain leads too..inflamm targets alphaTNF

3. ectodomain cleavage leads to paracrine signaling (membrane anchored growth factors)