[C] 1.42 Proliferative changes during regeneration. Fibrosis, elastosis, fibroelastosis, reticulosis, cirrhosis

Question 1

Reaction from the organism

Answer 1

Effect of the stimuli & pathogens

• Circulatory disturbances
• Regressive changes
• Proliferative changes
  
  • ​Mitosis
    
    • Few cycles
    • Stops after cells have finished their duty

Question 2

Mitotic activity of difference cells

Answer 2

• Stem cells
• Labile cells (epithelial cells)
  
  • Vegetative intermitotic
• Stabile cells (hepatocytes, renal tubular epithelium)
  
  • Reversible postmitotic
• Permanent cells (nerve cells, striated muscle)
  
  • Fix postmitoticus

Question 3

Cellular proliferative changes in local proliferative processes

Answer 3

• Mononuclear cells
  
  • Monocytes
  • Reticulum cells
  • Lymphoid cells
  • Macrophages
• Ectodermal cells in local processes
  
  • In skin & epidermis
  • In brain: gliac cells, astrocytes

Question 4

Difference cells during regeneration

Answer 4

• Histiocytes
• Lymphoid cells
• Firbroblasts

Question 5

Histiocytes during regeneration

Answer 5

• Large numbers after 12-24 hours
• Fix or mobile forms
  
  • From endothelium or from MPS cell
  • From bone marrow through the blood

Question 6

Lymphocyte during regeneration

Answer 6

• In lymphoid organs (primary or secondary)
• Solitaire or in groups
• Contact with antigen - differentiation
• Circulation and recirculation

Question 7

Fibroblasts during regeneration

Answer 7

• Following chronic stimuli
• Produces fibres - Connective tissue
• Angiofibroblast tissues
• Granulation tissue
• Mature connective tissue
• Scar tissue

Question 8

Diffuse proliferative changes in local proliferative processes occur in…

Answer 8

• Mononuclear-phagocyte system (MPS)
• Phagocytes

Question 9

Diffuse proliferative changes in local proliferative processes: Mononuclear-phagocyte system (MPS)

Answer 9

• Part of the immune system
• Proliferate
• Clear
• Removal & absorption
• Phagocytosis
• Produces antibody

Question 10

Diffuse proliferative changes in local proliferative processes: Phagocytes

Answer 10

• Microphages (granulocytes)
• Macrophages

Question 11

Signs of regeneration activity

Answer 11

Phagocytic activity increases:

• Basophilic cytoplasm
• Vacuolisation
• Chromatin structure rearrangement
• Different shape
• Mitosis
• Reactive reticulosis
• Activation: Endothel & reticulum cells

Question 12

Components of the extracellular matrix (stroma/interstitium):

Answer 12

• Fibres (Collagen, elastin, reticular)
• Proteoglycans (Chondroitin sulphate)
• Glycoproteins (Fibronectin, laminin)

Question 13

Changes of the extracellular matrix (stroma/interstitium)

Answer 13

• Increased or decreased amount
• Changes of the proteoglycans & glycoproteins
  
  • Pathological mucus production
• Changes of the fibres
  
  • Fibrosis
  • Elastosis
  • Fibroelastosis
  • Reticulosis
    
    • Sclerosis

Question 14

Fibrosis (overview)

Answer 14

Proliferation of the collagen

• Sometimes the proteoglycans also proliferate at the same time
• Increased amount of the stroma
• Requires vitamin C

Question 15

Forms of fibrosis

Answer 15

Relative:

• Degeneration of the parenchyma

Absolute:

• In case of inflammatory processes
• Due to ischaemia

Question 16

Give the steps of fibrosis

Answer 16

1. Ribosomes produce proto-collagen
2. Collagen monomers formed
3. Aggregation → Tropocollagen forms
4. Tropocollagen → Basic filaments
5. Basic filaments → Basic fibres
6. Basic fibres → Fibre bundles

Question 17

Fibrosis: Vit. C deficiency

Answer 17

• Decreased protocollagen & collagen monomer production
• Basic filaments stuck in the cell
• Basic filaments do not form fibres

Question 18

Tropocollagen is formed from…

Answer 18

3 polypeptide chains

Question 19

Where does fibrosis form?

Answer 19

• Circumscribed areas of the body
• Inside an organ, partially inside an organ
• Diffusely in an organ
• Intense fibroblast proliferation seen

Question 20

When is fibrosis observed?

Answer 20

• Chronic inflammation
• Replacing destroyed parenchyma
• Following chronic circulatory disturbance

Question 21

Fibrosis: Appearance

Answer 21

• Angiofibroblast tissue
• Granulation tissue

Question 22

Elastosis: Overview

Answer 22

• Proliferation of elastin and elastic fibres
• Elastin is also produced by the fibroblasts
• Elastin forms the elastic fibres

Question 23

Fibroelastosis

Answer 23

Fibrosis & elastosis occuring parallel

• Proliferation of collagen and elastic fibres

Question 24

Reticulosis

Answer 24

• Proliferation of the reticular fibres
• Reticulum cells produce fine reticulum fibres
• Found in all parenchymal cells
• Nearly all mesenchymal cells can produce reticulum fibres
• Forms: Primary or secondary

Question 25

Sclerosis: Overview

Answer 25

A special form of reticulosis

• The relative proliferation of the reticular fibres because of the degeneration of the parenchymal cells ar the same time

Question 26

Cirrhosis

Answer 26

• Chronic & long-lasting causes needed
• Chronic parasitic infections/toxic effect

Question 27

Cirrhosis: Steps

Answer 27

1. Chronic proliferative inflammation
2. Parenchyma degeneration
3. Unstructured parenchyma regeneration
4. Proliferation of connective tissue (fibroblasts)
5. Fibrosis (collagenous fibrosis)