Chronic Inflammation

Question 1

What is chronic inflammation?

Answer 1

Chronic inflammation is inflammation in which the cell populations are predominantly lymphocytes, plasma cells and macrophages.

Question 2

What is the predominant cell population composed of during chronic inflammation?

Answer 2

Lymphocytes
Plasma cells
Macrophages

Question 3

What does chronic inflammation feature?

Answer 3

Tissue damage/death (necrosis)

Healing/repair (granulation tissue, fibrosis and scarring`).

Question 4

Can chronic inflammation be developed from an acute inflammatory episode?

Answer 4

Yes.

Question 5

Can chronic inflammation arise as a primary pathology?

Answer 5

Yes.

Question 6

What does the clinical presentation of chronic inflammation usually feature?

Answer 6

No clear ‘sore bit’
Malaise
Weight loss

Question 7

Name 3 examples of chronic inflammation.

Answer 7

Autoimmune thyroiditis (functional glandular destruction)
Crohn's disease (ulceration/fibrosis of GI tract)
Leprosy (cutaneous nerve destruction)

Question 8

What is organisation?

Answer 8

An outcome of acute inflammation involving granulation tissue, angiogenesis, fibrosis and scar formation.

Question 9

What does organisation result in?

Answer 9

Formation of granulation tissue
Angiogenesis
Fibrosis and formation of scar

Question 10

What is a angiogenesis?

Answer 10

Formation of new blood vessels.

Question 11

What are the 4 steps of angiogenesis?

Answer 11

New vessels form from capillary buds.
VESF (vascular endothelial stimulating factor) released by hypoxic cells which stimulates proliferation.
Enzyme secretion aids the process.
Blood supply is enabled to enter the tissue.

Question 12

What factor is released by hypoxic cells to stimulate proliferation during angiogenesis?

Answer 12

VESF- Vascular Endothelial Stimulating Factor

Question 13

What does granulation tissue involve?

Answer 13

Angiogenesis, fibroblasts/collagen, macrophages

Question 14

What is the acute/chronic interface built on?

Answer 14

Acute inflammation developing into chronic inflammation.

Question 15

What does acute-on-chronic inflammation feature?

Answer 15

Exudate/neutrophils alongside lymphocytes/fibroblasts/fibrosis

Question 16

What type of tissue will acute-on-chronic inflammation feature?

Answer 16

Pyogenic tissue (pus).

Question 17

What are the products of granulation tissue?

Answer 17

• Fibrous tissue- scar (skin blemish)
• Fibrosis as a problem
• Chronic inflammation

Question 18

What is primary chronic inflammation developed from?

Answer 18

Autoimmune disease.

Question 19

How does primary chronic inflammation occur?

Answer 19

Autoantibodies are directed against the body’s own cell and tissue components (autoantigens). This leads to the damage and destruction of organs, tissues, cellular components and cells.

Question 20

What do lymphocytes do?

Answer 20

Part of immune system, many subtypes/functions, T-cells and B-cells, main functions in immune response and memory.

Question 21

What do plasma cells do?

Answer 21

Differentiated B-cells, involved in antibody production, intermediate size.

Question 22

What are the B-cell mechanisms?

Answer 22

Differentiate to plasma cells, facilitate immune response, act with macrophages (antigen presenting capacity) , immune memory.

Question 23

What are the T-cell mechanisms?

Answer 23

Produce cytokines (attract and hold macrophages, activate them, permeability), produce interferons (antiviral effects; attract/stimulate other cells, damage and kill other cells and destroy antigens.

Question 24

What do NK cells do?

Answer 24

Destroy antigens and cells (chemical mechanisms; innate immunity).

Question 25

What do macrophages do?

Answer 25

Destroy debris, antigen presenting cell, bone marrow production. (Long lived, motile phagocytes move from blood, contains enzymes such as lysosome, produces interferons and other chemicals)

Question 26

What do fibroblasts do?

Answer 26

Motile cells, metabolically active, make and assemble structural proteins such as collagens.

Question 27

What is granulomatous inflammation?

Answer 27

Inflammation characterised by the presence of granulomas in the tissues and organs.

Question 28

What is granulamatous inflammation stimulated by?

Answer 28

An indigestible antigen that the body can't get rid of.

Question 29

In what diseases is granulomatous inflammation often seen?

Answer 29

Serious and idiopathic (unknown causes).

Question 30

What are granulomas?

Answer 30

Granulomas are aggregates of epithelioid macrophages in tissue. May surround dead tissue.

Question 31

What may granulomas contain?

Answer 31

Giant cells | Neutrophils / eosinophils

Question 32

What are granulomas surrounded by?

Answer 32

Lymphocytes.

Question 33

What are giant cells?

Answer 33

Cells with a large cytoplasm/large nuclei- granulomas are not required for their formation.

Question 34

Name 4 types of giant cell.

Answer 34

Langhan's type Foreign body type Silcione-associated Warthen-Finkeldy

Question 35

Name 3 diseases of granulamatomous tissue that are relevant to global healthcare?

Answer 35

Tuberculosis Syphilis Leprosy

Question 36

Do non-infective granulomas exist?

Answer 36

Yes- seen in Rheumatoid arthritis, sarcoidosis and Crohn's disease.

Question 37

What is wound healing?

Answer 37

A repair process of tissue damage.

Question 38

What does wound healing involve?

Answer 38

Acute inflammation Granulation tissue formation Angiogenesis Fibrosis and scar formation

Question 39

What are surgical wounds an example of?

Answer 39

Healing by PRIMARY intention. Requires a minimal gap for the blood to clot. A small amount of granulation tissue will form and a linear scar will usually be made.

Question 40

What are other injuries an example of?

Answer 40

Healing by SECONDARY intention. | Involves the loss of granulation tissue ingrowth. This features contraction and scarring.

Question 41

What does the sequence of events involve in healing by secondary intention?

Answer 41

* injury, blood clot, acute inflammation, fibrin * many growth factors and cytokines involved * granulation tissue growth - angiogenesis * phagocytosis of fibrin * myofibroblasts move in and lay down collagen * contraction of scar * re-epithelialisation

Question 42

What factors favour wound healing?

Answer 42

``` Cleanliness Apposition of edges Sound nutrition Metabolic stability Normal inflammatory/coagulatory mechanisms ```

Question 43

What can impaired wound healing involve?

Answer 43

Dirty wound, large haematoma, poor nourishment, lack of vitamins (A/C), abnormal CHO metabolism, diabetes, corticosteroid therapy, angiogenetic inhibition.

Question 44

How does fracture healing differ from regular wound healing?

Answer 44

The bony structure must be repaired as well as the tissue.

Question 45

What is the pre-callus process of fracture repair?

Answer 45

* Trauma, fracture, haematoma * Bits of dead bone and soft tissue * Acute inflammation, organisation, granulation tissue, macrophages remove debris * Granulation tissue includes osteoblasts as well as fibroblasts

Question 46

What does the granulation tissue include in fracture healing?

Answer 46

Osteoblasts as well as fibroblasts.

Question 47

What is the callus-forming process of fracture repair?

Answer 47

The osteoblasts lay down woven bone. There are nodules of cartilage present which is followed by the remodelling of the bone- osteoclasts remove the dead bone, there is progressive replacement of woven bone by lamellar bone, and an eventual reformation of cortical and trabecular bone.

Question 48

What lays down woven bone in fracture repair?

Answer 48

Osteoblasts.

Question 49

What removes dead bone in fracture repair?

Answer 49

Osteoclasts.

Question 50

What does progressive replacement of woven bone by lamlelar bone result in within fracture repair?

Answer 50

Eventual reformation of cortical and trabecular bone.