Histopatholgy: Inflammation

Front 1

Acute Inflammation

Back 1

• Define acute inflammation
  
• Name cardinal signs
• Discuss causes
• Describe sequence of events
• Benefits
• Fate

Front 2

Definition

Back 2

• "Immediate and early response of living tissue to injury"
  

• Series of protective changes occur in tissue
  

- Dynamic mechanism

- Delivery of leukocytes and antibodies to site

-Innate

- Prominent Vascular response

Front 3

Cardinal Signs

Back 3

• Calor (Heat)
• Rubor (Redness)
• Tumour (Swelling)
• Dolor (Pain)
• Functionlaesa (Loss of function)

Front 4

Causes

Back 4

Exogenous Causes:

• Physical agents;Mechanical, thermal, radiation

• Chemical; Toxic gases, acids, alkalis
• Biological: Bacteria, viruses, parasites

Endogenous Causes:

• Circulation disorders; thombosis, infarction
• Abnormal enzymes - eg. acute pancreatitis
• Metabolic products; uric acid, urea

Front 5

Sequence of Events

Back 5

1. Chemically initiated
2. Changes in vessel radius - flow
3. Change in permeability of wall - exudation
4. Movement of neutrophils from vessel to extracellular space

Front 6

1. Chemical Mediators

Back 6

• Complement: Chemotaxis, Opsonisation, MAC
• Kinins: Vasoactive
• Prostaglandins
• Platelet activating factors
• Cytokines

- Vasodilation and increased permeability of vessel walls. Chemotaxis and neutrophil adhesion (pain)

Front 7

2. Vascular Response - Flow

Back 7

• Initially vasoconstriction

- Spasm (nerves) from release of catecholamine by sympathetic nerve endings

• Followed by vasodilation

- Induced by chemical mediators; histamine and NO

- rubor, calor, tumour, pain, functionalaesa

Front 8

3. Vascular Permeability - Exudation

Back 8

• Exudation/movement of fluid out of capillaries and tissue spaces dilutes offending agent
  
• Gaps between endothelial cells
• Direct injury
• Leukocyte dependent injury
• Increased transocytosis / angiogenesis

Front 9

4. Movement of Neutrophils

Back 9

• Neutrophil polymorphnuclear leukocyte most important cell

• Blood flow slows - loss of normal lamina flow

• Neutrophils found near endotheliim

Front 10

Cellular Response (5)

Back 10

1. Margination

- Transiently stick; E, L & P-Selectin

2. Pavmentng

- Firm adhesion ICAM

3. Transmigration

- "Diapedesis" ; focal degradation of basement membrane

4. Chemotaxis (migration)

5. Phagocytosis

Front 11

Aiding Injury (5)

Back 11

• Vasodilation

- Increases delivery and temperture, removes toxins

• Exudate

- Deliver Ig and fibrinogen, dilutes toxins amd increases lymphatic drainage

• Increased lymphatic drainage

- Delivers 'bug' to phagocytes and antigens to immune system

• Cells

- Remove pathogens and necrotic debris

• Pain and Loss of Function

- Enforces rest, reduce further trauma

Front 12

Benefits (5)

Problems (2)

Back 12

• Rapid, non-specific response
• Signs and Loss of function
• Neutrophils destory organism and denature antigen for macrophages
• Plasma porteins localise process
• Resolution and return to normal

1. Local
2. Systemic

Front 13

Fate

Back 13

Front 14

Chronic Inflammation

Back 14

• Define chronic inflammation
  
• Outline causes
  
• Describe cell types involved
• Examples

Front 15

Definition: Chronic Inflammation

Back 15

Inflammation of prolonged duration in which active inflammation, tissue destruction and attempts at repair are occurring simultaneously.

Front 16

Signs

Back 16

Characterised by;

• Presence of chronic inflammatory cells
• Proliferation of blood vessels
• Fibrosis and necrosis tissue

Front 17

Causes (4)

Back 17

• Persistent or resistant infection

• Prolonged exposure to potentially toxic agents
  

- Exogenous; Silica

- Endogenous; Athersclelrosis

• Chronic inflammatory coniditions unknown cause: Crohn's disease

• Autoimmune conditions; Rheutamoid arthritis, hypothyroidism
• 
  

Front 18

Cell Types Involved (3)

Back 18

1. Macorphages
2. Lymphocytes
3. Plasma cells

Front 19

1. Macrophages

Back 19

• Derived from monocytes

- produced in bone marrow

- released into peripheral blood

- circulate 1-3 days

• Macrophages

- Proliferate within tissue

- Activated by chemical mediators; cytokines, lymohocyte products

- Phagocytic capabilities

- Retain organisms they cannot kill:

(Foreign body giant cells, Granulomas)

- Present antigen to lymphocytes

Front 20

Interaction: Macrophages and Lymphocytes

Back 20

• Activate macrophages

• Macrophages present antigen to lymphocytes

Front 21

2. Lymphocytes

Back 21

• Derived from stem cells
  

- Develop in bone marrow

• T and B lymphocytes

- present in lymph nodes, "monitor" blood

- different functions and immunological profiles

Front 22

T Lymphocytes

Back 22

• Migrate from bone marrow, mature in thymus

• T helper cell

- recognise foreign antigen

- produce cytokines and stimulates other lymphocytes

- present antigen to B lymphocytes

• Cytotoxic T lymphocytes

- destroy virus -infecte cells

- suppress activity of B cells

Front 23

B Lymphocytes

Back 23

• Transform into plasma cells on contact with antigen

Front 24

3. Plasma Cells

Back 24

• Activated B cells
• Produce antigen specific antibodies

- Antibodies locate, neutralise and eliminate

Front 25

4, Other Cells (2)

Back 25

• Eosinophils

- removal of fibrin

-fight viral infection (RNases present in granules)

• Fibroblasts

breakdown fibrin clots; wound healing

Front 26

Examples of Chronic Inflammation (7)

Back 26

1. Chronic Cholecystitis
2. Chronic Endometritis
3. Rheutamoid Arthritis
4. Gout: Foreign body reaction
5. Crohn's Disease
6. Sacroidosis

- Pulmonary

- Cutaneous

7. Tuberculosis

- Cavitating Pumlonary

- Renal

Front 27

Chronic Endometritis

Back 27

• Cause of heavy and irregular menstrual periods
• May be due to infection or foreign body response
• Characterised by plasma cell in stroma of endometirum

Front 28

Crohn's Disease

Back 28

• Affects part of Gastrointestinal Tract (GIT)
• Associated with non-necrotising granulomas

Front 29

Scaroidosis

Back 29

• Multisystem chronic disorder
• Characterised by non-necrotising granulomatous inflammation
• Frequently presents with;

- Bilateral hilar Lymphoadenopathy

- Ocular and Skin lesions

- Pulmonary inflitration

• Liver, spleen, lymphnodes, sal. glands, heart, NS, muscles, bones, etc.. may be involved