Acute inflammation

Nota:

• Process which cells and exudate (Fluid accumulation) in irritated tissues and usually tend to protect them from further injury

1. Signs

   Nota:

   • Redness Heat Swelling Pain Loss of Function
2. Key Points

   Nota:

   • It is a microcirculatory response to injury. Increased vasodilation and increased permeability. It is an essential for defense against infection and precursor to wound healing. Excessive/inappropriate response is harmful (i.e allergic reaction) tightly regulated by chemical mediators.
3. Causes

   Nota:

   • CHINPIG

   Adjunto:

   • Injurious Agents
4. Mechanisms
   1. Vascular Response

      Nota:

      • Increased permeability of vasculature to let in proteinaceous exudate to slow blood flow. In venules, it will be dilated and will store the most amounts of blood. Momentary arteriolar constricution then vasodilation then the microvascular beds will open up and dilate and hence raise hydrostatic pressure. Helps leukocytes to bind Stasis of blood may allow endothelial changes
   2. Swelling and Exudation

      Nota:

      • It dilutes the irritant. Increased extravasation of plasma proteins such as immunoglobulins and coagulation proteins.
      1. Possible harmful effects

         Nota:

         • Swelling: Pain Swelling at sites such as airway, the brain cavity Microbe may spread to exudate May lead to thrombosis and ischaemia.
      2. Cellular emigration

         Nota:

         • Margination (come close to) THen it adhere to endothelium Emigrate to tissue Chemotaxis (neutrophils and monocytes)
      3. Type of exudate

         Nota:

         • Depends on the nature and dosage of irritant. Organ or tissue involved. Nature of the host response
5. Lymphatics

   Nota:

   • Facilitate immune response It is also a possible route of microbial spread.
6. Chemical mediators

   Nota:

   • Cell-derived such as histamine or secreted in response to inflammatory stimulus such as cytokines or oxygen radicals. Plasma factor: Complement activation  Or Factor XII
7. Outcomes

   Nota:

   • As per last lecture, it will either be chronic or acute. Recovery is dependent, it will either go into repair or replacement.

   Adjunto:

   • Injurious Agents