Objective 5: Five Types of Inflammatory Responses to Infection (+ Examples)

Question 1

Suppurative (Polymorphonuclear) Inflammation

Answer 1

(PMN, pus formation)

• caused by PYOGENIC (pus forming) bacteria
• characterized by: increased vascular permeability + leukocytic infiltration by neutrophils
• baceria recruit neutrophils:
  
  • directly by release of chemoattractive peptides
  • indirectly by release of endotoxin which stimulations macrophages to realease cytokines that chemoattract neutrophils
• Ex: pneumococcal pneumonia (insert pic)
  
  • note: intra alveolar PMN exudate and intact alveolar septa

Question 2

Mononuclear and Granulomatous Inflammation

Answer 2

(Granulomatous is caused by certain tissue. **TB, syphillus)

• diffuse, predominantly mononuclear interstitial infiltrated forn in response to pathogens
• incude LYMPHOCYTES (syphillus chancres) and MACROPHAGES (mycobacterium granulomas) depending on the pathogen and host response
• Granulomatous inflammation occurs when aggregates of altered macrophages form or fuse to form GIANT CELLS
• Ex: Secondary Syphillus with perivascular infiltrate and endothelial proliferation
  
  • note: secondary syphilis in ther dermis with perivascular lymphoplasmacytic infiltrate and endothelial proliferation (insert pic)

Question 3

Cytopathic-Cytoproliferative Inflammation

Answer 3

• reactions characteristic of virus-mediated damage to individual hot cells int he absence of hos tinflammatory response
• results in:
  
  • incluion bodies (CMV-cytomegalovirus)…nuclear or cytoplasmic aggregates of stainable substances, usually proteins
  • polykaryons following cell fusion (measles)
  • blisters due to cell damage (Herpesvirus)
  • morphologic lesions (venereal warts/HPV)
  • dysplastic changes and cancers
• Ex: Herpesevirus blister
  
  • note:herpesvirus blister in mucosa

Question 4

Necrotizing Inflammation

Answer 4

• rapid and severe tissue damage with predominant cell death in the absence of inflammatory infiltrates
• caused by uncontrolled viral infections, secreted bacterial toxins or cytolysis of host cells in protozo infections (eg necrotizing fasciitis caused by Group A streptococcus)

Question 5

Chronic Inflammation and Scarring

Answer 5

• chronic inflammation can lead to either complete healing or to extensive scarring
• several inert organisms cause damage by the scarring response (Ex: schistosome eggs)
• Ex: Schistosoma Haematobium infection
  
  • note: Schistosoma Haematobium infection of the bladder with numerous calcified eggs and extensive scarring (insert pic)