Inflammation Types and Characteristics Quiz

Types of Non-Suppurative Inflammation

• Catarrhal inflammation: characterized by excessive mucus secretion, example: catarrhal rhinitis
• Membranous inflammation (Pseudomembranous inflammation): severe acute inflammation, characterized by pseudo membrane formation, examples: diphtheria, bacillary dysentery
• Sero-fibrinous inflammation: acute inflammation with excessive fluid exudate rich in fibrinogen, example: inflammation in serous sacs (pericardium, pleura)
• Serous inflammation: acute inflammation with excessive serous exudate, example: mild burns, herpes simplex vesicles
• Hemorrhagic inflammation: acute inflammation with cell exudate rich in RBCs due to vascular damage, example: smallpox
• Necrotizing inflammation: acute inflammation characterized by marked tissue necrosis and putrefaction, caused by Borrelia vincentii in immunocompromised patients, examples: trench mouth, cancrum oris, ANUG (acute necrotizing ulcerative gingivitis)
• Allergic inflammation: inflammation due to allergies, example: latex allergy

Chronic Inflammation

• If inflammation persists for weeks or months after initial injury
• Progression from acute inflammation
• Recurrent episodes of acute inflammation
• Chronic inflammation de novo
• Types: Chronic non-specific inflammation, Chronic specific inflammation (granulomas)

Chronic Non-Specific Inflammation

• Different irritants produce chronic inflammation with similar microscopic features
• Microscopic picture: diffuse accumulation of macrophages and lymphocytes, less prominent vascular changes, few inflammatory exudate, and new fibrous tissue formation at the site of injury
• Examples: Chronic abscess, chronic suppurative osteomyelitis

Chronic Specific Inflammation (Granulomatous Inflammation)

• Characterized by granuloma formation
• Granuloma components: huge aggregates of epithelioid cells (activated macrophages), epithelioid cells may fuse to form multinucleated giant cells, surrounded by a cuff of lymphocytes and occasional plasma cells
• Examples: TB, syphilis, sarcoidosis, foreign body granulomas

Causes of Granulomatous Inflammation

• Bacterial: tuberculosis, leprosy, syphilitic gumma, actinomycosis
• Parasitic: schistosomiasis, filariasis, toxoplasmosis
• Fungal: cryptococcosis, blastomycosis
• Inorganic dusts: silicosis
• Foreign body: suture, breast prosthesis, wood
• Unknown etiology: sarcoidosis, Crohn's disease

Microscopic Picture of Granuloma

• Huge aggregate of epithelioid cells (activated macrophages)
• Multinucleated giant cells
• Surrounded by a cuff of lymphocytes and occasional plasma cells

Types of Granulomas

• Tuberculous Lymphadenitis: eosinophilic debritic material, caseous necrosis, modified macrophages, epithelioid cells, giant cells, collar of lymphocytes surrounding epithelioid cell aggregates.
• Sarcoidosis (non-caseating granulomas): displays Shouman bodies and Asteroid bodies

Wound Repair by Regeneration

• Replacement of damaged tissue by healthy tissue of the same kind
• Depends on: cells' ability to divide and intact supporting framework (connective tissue stroma)
• Cell types according to proliferative potential:
  • Labile cells: continuously dividing cells in postnatal life (short lifespan), examples include epidermis, surface epithelium of mucous membranes, and hemopoietic cells. Injury to these results in complete regeneration if stroma is intact
  • Stable cells: normally undergo few postnatal divisions but can divide when activated or after injury, examples include hepatocytes, renal tubular cells, glandular cells, mesenchymal cells, smooth muscle, osteoblasts, cartilage cells, endothelium, and connective tissue cells. Injury results in complete regeneration if stroma is preserved
  • Permanent cells: cannot undergo mitotic division in postnatal life; examples include cells in the central nervous system and heart; once destroyed, cannot be regenerated

Wound Repair by Fibrosis

• Replacement of damaged tissue by granulation tissue that matures into fibrous tissue

Granulation Tissue

• Transitional, highly vascular connective tissue formed by capillaries and fibroblasts
• Characteristics: red, moist, granular, easily bleeding, painless, resists infection

Repair of Skin Wounds

• Epidermis/epithelium heals by regeneration (using labile cells)
• Dermis/sub-epithelium heals by scarring (using stable cells)
• Macrophages clear the area.
• Epithelial proliferation
• Healing

Primary Intention Wound Healing

• Clean surgical wound, minimal tissue loss, sterilization, well-opposed edges, heals quickly, minimal complications, thin linear scar

Secondary Intention Wound Healing

• Gaping wound, excess tissue loss, infected with tissue debris, not well-opposed edges, slow healing, common complications, large irregular scar

Repair of Bone Fractures

• Steps: hematoma formation (week 1), internal/external callus formation (weeks 2-3), callus ossification (1-4 months), consolidated fracture and bone remodelling (4-12 months)
• Requirements: fracture fixation, immobilization.
• Complications: infections, non-union, malunion, nerve injury, delayed union, fibrous union

Important Questions

• Enumerate and define types of non-suppurative inflammation
• Histopathology of granuloma
• Difference between TB and sarcoidosis granuloma
• Repair by regeneration (different cell types)
• Repair by fibrosis (granulation tissue components)
• Difference between 1ry and 2ry intention healing
• Healing mechanism of bone fracture

Test your knowledge on the different types of inflammation and their defining characteristics. This quiz covers aspects such as membranous inflammation, fluid exudate types, and cell regeneration. Perfect for medical students and professionals looking to refresh their understanding of inflammatory responses.