VM 704 (Pathology)- Inflammation, Healing, & Repair

When is repair of injured tissue initiated?

Right at the onset of inflammation

What are the 3 cardinal signs of inflammation?

1. Hemodynamic changes

2. Increased vascular permeability

3. Efflux of WBCs

What happens to vessels and capillary beds when there is inflammation?

They dilate and open

What are the 2 main causes of vascular permeability?

1. Direct damage to vessel

2. Inflammatory mediators

What is the appearance of serous inflammation?

Thin, watery fluid

What is the purpose of serous inflammation?

To dilute or wash away the injurious agent

What does catarrhal inflammation consist of?

Mucus secretions (can only occur in tissues containing goblet cells)

Which tracts have goblet cells?

The respiratory tract and the urogenital tract

What is found in the exudate of fibrinous inflammation?

Fibrinogen and clotting proteins

As scar tissue grows over a wound, what does fibrinous inflammation develop into?

Fibrous inflammation

What is the main cause of fibrinous inflammation?

Infectious disease

How is fibrinous inflammation resolved?

Enzymatic fibrinolysis and phagocytes

What kind of necrosis looks like “corn flakes”?

Fibrinonecrosis

What is the typical form of fibrinous inflammation?

“Stringy” or “clot/sheet like”

What is the sequence of WBC into the tissue?

1. Neutrophils

2. Macrophages

3. Lymphocytes

Which types of cells have multiple nuclei?

Neutrophils

What is chemotaxis?

Directed movement up a concentration gradient

Which types of cells are the first line of defense in inflammation?

Neutrophils

What is the appearance of suppurative/purulent inflammation?

Liquefied, thick, creamy, yellow exudate

What are the 2 main purposes of phagocytes?

1. Destroy injurious agent

2. Clean up debris

What is the definition of cellulitis?

Inflammation of connective tissue

What is the definition of phlegmon?

Pocket of pus in subcutis

What is the definition of empyema?

Accumulation of pus in body cavity

What is the definition of fasciitis?

Purulent inflammation of fascia

Which kinds of cells are present in fibrinopurulent inflammation?

Neutrophils

What are heterophils?

The amphibian and reptile equivalent of neutrophils.

What kinds of cells are often involved in allergies/hypersensitivity reactions?

Eosinophils and mast cells

What kinds of cells are often involved in bacterial infections?

Neutrophils

What are the main subtypes of macrophages?

1. Alveolar

2. Pulmonary intravascular

3. Microglia

4. Kuppfer

5. Epithelioid

6. Multinucleate giant cell

What are the 3 main causes of chronic inflammation?

1. Continuation of acute inflammation

2. Repeated injury

3. Insidious onset

What are the cell types involved in granulomatous inflammation?

Sheets of epithelioid macrophages

What condition is an example of a pyogranulomatous lesion?

Furunculosis

What is the definition of a granuloma?

Aggregate of macrophages + multinucleated cells around a central debris/foreign body

What are the 3 ways healing and repair can occur?

1. Parenchymal regeneration

2. Fibrosis (scarring)

3. Replacement by fibrous tissue

What are the 2 main factors affecting healing?

1. Stromal integrity

2. Regenerative capacity of tissue

Which 2 types of tissue can never regenerate?

1. Neurons

2. Muscle

Do blood cells continuously proliferate?

Yes

What are the 3 main phases of granulation tissue formation?

1. Inflammatory phase

2. Proliferative phase (new tissue)

3. Remodeling phase (collagen fibers are reorganized)

What are the 3 main types of cells found in granulation tissue?

1. Macrophages

2. Fibroblasts

3. Endothelial cells

What is the definition of healing by first intention?

Wound edges opposed, rapid healing, minimal scarring

What is the definition of healing by second intention?

Defect filled with granulation tissue, potential for significant scarring

What is the definition of ankylosis?

Scarring around a joint so it cannot move