Overview of Inflammation #2 (1/12/16) Flashcards
What changes occur in blood flow during acute inflammation?
Vasodilation = Increased vascular permeability
*Fluid can leak out of blood vessels causing tissue edmea
Vasodilation is mediated by ____, ____ and ______.
Nitric Oxide
PG’s
Histamine
What is the first cell to arrive a site of acute inflammation?
PMN’s (Neutrophils)
What are the 2 types of fluid that accumulate in inflammation?
Transudate = low protein fluid, low specific gravity
non-inflammatory intact endothelium,
Inflammatory - Early endothelial contraction
Exudate = High protein content, high specific gravity.
What are they 3 types of exudate?
Fibrinous = high protein, few cells Purulent = High protein, many cells Sanguineous = high protein, blood
What are the mechanisms that can increase Vascular permeability?
Endothelial contraction (Reversible) - Immediate and transient
Endothelial Retraction
- Delayed = develops in 4-6 hrs and sustained for 24+ hrs
Direct injury (non lethal) - Immediate or delayed but also sustained.
Endothelial cell contraction is mediated by what 4 things?
PAF
Histamine
Bradykinin
Leukotrienes
After Direct Endothelial injury, what mediates the increased vascular permeability?
Injurious agents
ROS/enzymes from PMN’s
*Endothelial cell retraction is mediated by IL-1 TNF and IFN-Y
What activates Endothelial cell retraction?
IL-1, TNF and IFN-Y
Activated Endothelial cells produce _______ and ______.
PGI2 and NO (vasodilation)
What molecule allows for transport of molecule out of blood vessel?
PECAM
What is the order of events Leukocyte migration? (5)
- Margination = Physical forces
- Rolling - selectins (speed bumps that slow molecules down) (weak, transient sticking)
- Adhesions - intergrins “Docking station” (ICAM and VCAM)
- Emigration or Transmigration - PECAM “Shuttle doors”
- Chemotaxis = movement alone the concentration gradient of chemotactic factors.
What are the steps of Phagocytosis?
- Recognition and attachment = Microbes bind to phagocyte receptors.
- Engulfment = Phagocyte membrane zips up around microbe.
- Killing and degradation
The presence of ______ defines acute inflammation.
Neutrophils (They release ROS and induce apoptosis)
What cell shows up after Neutrophils?
Monocytes and macrophages around day 3 (48hrs)
What are the functions of monocytes/macrophages?
- phagocytosis
- Cytokines
- Antigen presentation
- Plasma proteins
- Enzymes
- “Clear up mess the neutrophils made”
What are other Inflammatory cells that turn up?
Lymphocytes = immune functions
Eosinophils = Allergic Reactions, parasites
Mast cells = histamine
______ is diffuse tissue infiltration by PMN’S with Edema.
Cellulitis
_____ is a localized collection of PMN’s or liquefactive necrosis (Pus)
Abscess
How do features of Chronic inflammation differ from acute inflammation?
Acute = days - weeks Chronic = days - years Acute = localized Chronic = maybe systemic Acute = no immune response Acute = often reversible
What are the 2 types of Chronic inflammation?
Non-specific
Granulomatous
*Tissue distraction leading to fibrosis (scarring) is common.
What can cause Granulomatous inflammation?
Inorganic matter
Bacterial infections (like TB)
Parasitic infections (Toxoplasmosis)
Uncertain etiology
What causes histamine release?
Physical injury Ag-IgE, C3a and C5a, Cytokines
Prostaglandins are important for ______.
Vasodilation
Thromboxane A2 is important for ________.
Vasoconstriction
What are 3 important chemical inflammatory mediators?
Histamine releasers
Prostaglandins and Leukotrienes
Thromboxane A2
What does Labile mean?
Continuously dividing (hematopoietic cells, surface epithelium)
What does Stable refer to?
Tissue with some replicative activity (Parenchymal cells, smooth muscle cells, fibroblasts)
What does Permanent refer to in wound healing?
non-proliferative tissue (Neurons, cardiac muscle)
What are the effects of growth factors in wound healing?
- Epithelial proliferation
- Monocyte Chemotaxis
- Fibroblast proliferation
- Angiogenesis
- collagen synthesis
What is the primary cause of delayed healing?
Infection!
What are other factors that affect wound healing?
- nutrition
- steroid therapy
- mechanical factors
- poor tissue perfusion
