Revision Flashcards
(28 cards)
What is the definition of inflammation?
Reaction of vascularized tissues to cell injury or death
Aim: reduce injury/infection, remove damaged tissue, repair tissue
What are the three main mechanisms of inflammation?
Diluting – Destroying – Neutralizing (DDN)
These mechanisms work together to address tissue injury and infection.
What occurs during the vascular phase of inflammation?
Increased blood flow (vasodilation) and increased vascular permeability
This causes redness (erythema) and warmth.
What is the cause of redness and warmth during inflammation?
Arteriolar vasodilation
Differentiate between exudate and transudate.
Exudate: protein-rich fluid and cells, high osmotic pressure
Transudate: low protein, no blood cells, increased hydrostatic pressure
What are the steps involved in the cellular phase of inflammation?
- Margination and rolling
- Firm adhesion (via integrins + chemokines)
- Diapedesis (transmigration, depends on PECAM)
- Chemotaxis (movement through interstitial tissues)
What are the primary functions of leukocytes during inflammation?
Ingest offending agents, kill bacteria, eliminate necrotic tissue
What are some receptor-dependent mediators of inflammation?
Cytokines, prostaglandins
Name two non-receptor mediators of inflammation.
ROS, nitric oxide
What is the half-life of nitric oxide?
2–6 seconds
What are the three types of NOS that produce nitric oxide?
nNOS, iNOS, eNOS
What is the role of complement in systemic inflammation?
C3a/C5a = vasodilation/chemotaxis; C3b = opsonisation
What causes chronic inflammation?
Persistent infections, autoantigens, exogenous materials
What are the features of chronic inflammation?
Mononuclear infiltration, tissue destruction, angiogenesis/fibrosis
What are the two types of macrophage activation?
Classical: lysosomal enzymes, NO, ROS (kill microbes)
Alternative: tissue repair
What do B lymphocytes differentiate into?
Plasma cells (antibodies)
What cytokine do CD4+ Th1 lymphocytes produce to activate macrophages?
IFN-γ
What cytokines do CD4+ Th2 lymphocytes produce?
IL-4, IL-5, IL-13
What is the result of Th17 lymphocyte activation?
Recruitment of neutrophils/monocytes via IL-17
What are activated macrophages called in granulomatous inflammation?
Epithelioid cells
What type of necrosis is associated with tuberculosis?
Caseous necrosis (cheesy center)
What is a characteristic of Crohn’s disease granulomas?
Non-caseating granulomas
What are the systemic signs of inflammation?
↑ HR, BP; ↓ sweating; chills; anorexia; somnolence; malaise
What does ‘shift to the left’ refer to in laboratory findings?
Immature neutrophils in the blood
