Different modes of injury and healing

• acute injury progresses to acute inflammation

• if not much tissue damage occurs, then the capillary bed doesn’t have to grow new capillaries, and resolution is rapid

• if there is more extensive damage, a war between neutrophils and bacteria begins

  • the body builds a fibrous capsule around this war

  • you eventually develop a bag of pus, an abscess

  • neutrophils turn into soup and as a result the oncotic pressure inside the abscess increases

  • the abscess can burst, and indeed this is how they resolve themselves

  • then, assuming everything in there is dead, the body can reabsorb what used to be inside the abscess

• injury causing chronic inflammation, often involving lymphocytes, leads not to abscess formation but to fibrosis

  • dense fibrosis is sometimes reabsorbed by macrophages or else remains as a disfiguring scar

  • then, regrowth of capillaries and venules occurs, a process termed revascularization

  • healing is accomplished by regeneration

Category: Pathology Notes