Exam #1: ECM Flashcards Preview

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Flashcards in Exam #1: ECM Deck (49):
1

What are the molecular constituents of the ECM?

- Ground Substance
- Fibers

2

What are the different types of ground substance?

- Glycosaminoglycans
- Proteoglycans
- Water
- Adhesive glycoproteins

3

What are different fibers in the ECM?

- Collagen
- Reticular Fiber
- Elastic

4

Reticular Fiber

Type III Collagen

5

Granulation Tissue

- Replacing functional cells w/ ECM in response to injury
- Hallmark of tissue repair
- Loose, edematous, & vascular

6

Mature Scar

Loose granulation tissue replaced with dense collagenous tissue

7

How does the ECM drive the cell cycle?

- No contact w/ substrate= low probability of division
- Cell perched on adhesive patch= increases probability of division
- Cell spread on large adhesive patch= high probability of division

8

Focal Adhesions

Connection between cell & ECM that regulate:

- cell division
- growth
- survival

9

Injury to cell with intact matrix

Regeneration by functional cells

10

Injury to cell & matrix

Repair by granulation & scarring (non-functional cells)

11

What happens to the hydrated state of tissue when there is excessive accumulation of glycosaminoclycans?

Increase b/c of negatively charged carboxyl groups that attract water

12

What are the different glycosaminoglycans that exist in the ECM?

- Dermatin Sulfate
- Chondroitin Sulfate
- Heparan Sulfate
- Keratan Sulfate
- Hyaluronic Acid
- Heparin

13

Exopthalmous

- Grave's Disease
- Autoantibodies to TSH
- Causes increased deposition of glycosaminoglycans in the retro-orbital space
- Specifically, Chondriotin Sulfate & HA
- Increases hydration state and pushes the eyes outward

14

Proteoglycan

- "Bottle-brush" appearance
- Core protein with Glycosaminoglycans attached
- Link with HA to form an aggrecan

15

Syndecan

- Transmembrane proteoglycan
- FGF receptors adjacent
- Co-receptor for FGF receptor
- Attached by Heparan Sulfate

16

Perlecan

- Dark brown in appearance
- Found in the interface between epidermis & dermis
- Surrounds blood vessels
- Plays a role in the development of skeletal tissue

17

Perlecan- Null

Defective skeletal development

18

What are the three typical binding domains of a multiadhesive glycoprotein?

1) Cell adhesion molecule aka CAM e.g. Integrin
2) Collagen fibers
3) Proteoglycans

19

What are the six types of adhesive glycoproteins?

1) Fibronectin
2) Laminin
3) Entactin
4) Tenascin
5) Chondronectin
6) Osteonectin

20

Laminin

Adhesive Glycoprotein in Basal Lamina

21

Entactin

Adhesive Glycoprotein in Basal Lamina

22

Tenascin

Adhesive Glycoprotein in Embryonic Tissue

23

Chondronectin

Adhesive Glycoprotein in Cartilage

24

Osteonectin

Adhesive Glycoprotein in Bone

25

What is the role of Fibronectin in development?

- Normal development of salivary glands
- When blocked, glands do not differentiate

26

Laminin

Binding domains:
- Dystroglycan (cell-adhesion molecule)
- Collagen
- Heparan Sulfate (proteoglycan)

Plasma membrane of muscle

27

What is the most abundant fiber type seen in the ECM?

Collagen

28

Type I Collagen

- Most abundant
- Associated with tendons, ligaments, fibrocartilage, cementum, dentin, bone, dermis, & any organ w/ a connective tissue capsule
- Acidophillic (pink)

29

Type II Collagen

- Hyaline & Elastic Cartilage

30

Type III Collagen

- Reticular Cartilage
- Spleen, liver, lymph nodes, smooth muscle, skin, lung
- Forms a "delicate network" for cells
- Argyrophilic (silver loving)
- PAS positive (carbohydrates associated)

31

Type IV Collagen

Basal Lamina

32

Type VII Collagen

- Dermis
- Connects the basal lamina with the underlying dermis

33

What amino acid is measured to calculate the concentration of collagen?

Hydroxyproline

34

How is collagen turned over?

- Proteolytic Degradation
- Phagocytic Degradation

35

What do cardiac muscle cells appear in response to a remote MI?

- Blue from collagen deposition (granulation first)
- Trichome method of staining

36

Keloid

Excessive accumulation of collagen/ excessive scar formation

37

What are Elastic Fibers composed of?

- Proelastin
- Microfibril-associated glycoprotein
- Fibrillin 1&2

38

What are unique amino acids to elastic fibers?

Desmosine & Isodesmosine

39

Ehler's Danlos Type IV

- Type III Collagen (Reticular Fibers)
- Varicose veins, aortic rupture, intestinal rupture

40

Ehler's Danlos Type VI

- Defective Hydroxylation of Lysine
- Hyperelasticity of the skin, rupture of the eyeball

41

Ehler's Danlos Type VII

- Type I Collagen
- Joint dislocation & hypermobility

42

Marfan's Syndrome

- Defective synthesis of elastic fibers
- Aortic aneurysm, skeletal defects, pectus excavatum, scoliosis

43

Basal Lamina

- Interface between epithelial cells & extracellular components/ underlying connective tissue
- Found in epithelium, kidney glomerulus, & muscle cell

44

Basement Membrane

- Basal Lamina ( Lamina lucida & Lamina densa)
- PLUS Lamina fibroreticularis

45

Lamina Lucida

- Laminin
- Entactin
- Integrins
- Dystroglycans

46

Lamina Densa

- Type IV Collagen
- Fibronectin
- Perlecan

47

Lamina Fibroreticularis

- Fibronectin
- Type I Collagen
- Type III Collagen

48

What anchors the Lamina Densa to the Fibroreticularis?

Type VII Collagen

49

Membranous Nephropathy

- Autoantibodies produced against antigens
- Deposit in the basal lamina of the glomerulus
- Compliment is activated
- Leads to a degradation of the wall of the vasculature