Pathology of inflammation Flashcards
Learning Outcomes
Define and describe the pathological features of:
- Acute inflammation
- Chronic inflammation (non-specific)
- Granulomatous chronic inflammation
- Eosinophil rich inflammation
- Abscess
- Empyema
- Ulcer
- Sinus tract
- Fistula
What is acute inflammation?
Initial defensive tissue response to an insult such as infection. Consists of infiltration by neutrophils*, increased vascular leakiness and increase amount of chemicals (cytokines). *Usually involves neutrophils (especially in bacterial infection). However, in acute viral illness we usually see lymphocytes rather than neutrophils.
What is chronic inflammation (non-specific)?
Infiltration of tissues by lymphocytes, plasma cells and histiocytes. May be due to persistent insult but most commonly due to auto-immune disease. eg. Rheumatoid arthritis.
What is granulatomous chronic inflammation?
Special type of chronic inflammation where granulomas are seen histologically. Granulomas are round collections of macrophages (histiocytes) with occasional multinucleated cells (giant cells).
Examples: sarcoid, tuberculosis, reaction to foreign body material
What is eosin rich inflammation?
Type 1 hypersensitivity reactions such as drug reaction, insect bite reaction, atopic eczema, eosinophilic asthma,
What is an abcess?
Accumulation of pus (neutrophils/debris/necrotic bacteria) within tissue.
What is an empyema?
Accumulation of pus (neutrophils/debris/necrotic bacteria) in a cavity like the pleural cavity
What is an ulcer?
A defect in full thickness epithelium associated with inflamed necrotic debris
What is a sinus tract?
A blind ended channel leading from a skin or mucous surface to an underlying focus of inflammation or infection, usually lined by granulation tissue.
What is a fistula?
An abnormal connection (tunnel/passage) between two organs. Often due to chronic inflammation (traumatic childbirth) or cancer.
What is caseous necrosis?
A type of necrosis seen in granulomas due to tuberculosis. Naked eye appearance is cheesy and microscopic appearance is dirty / basophilic / dark.
What is the ziehl-neelsen stain and what is it used for?
Ziehl–Neelsen staining is a bacteriological stain used to identify acid-fast organisms, mainly Mycobacteria. (tuberculosis)
What is granulation tissue?
New connective tissue and numerous new blood vessels that form in the base of an ulcer as part of repair process.
What is erosion?
A partial defect in the superficial layers of epithelium.
What is cellulitis? (hint- not inflammation of cells- a misnomer)
Bacterial infection of the epidermis, dermis and subcutaneous fat.
