Inflammation

inflammation

1. Inflammation and Repair Lecture 6

2. Outcome of Acute Inflammation & Morphologic Patterns in Acute Inflammation

3. OBJECTIVES AND KEY PRINCIPLES TO BE TAUGHT:   Upon completion of this lecture, the student should: 1. Enumerate the fate of acute inflammation and the conditions that leads to resolution or fibrosis 2. Discuss abscess formation and its fate 3 .Discuss how chronic inflammation follows acute inflammation 4. Enumerate the morphologic patterns of acute inflammation. 5. Define: abscess, furuncle, carbuncle, and cellulitis and identify their aetiology and morphology

4. Inflammation Outcome Acute Inflammation Resolution Chronic Inflammation Abscess Sinus Fistula Fibrosis/Scar Ulcer Injury Fungus Virus Cancers T.B. etc.

5. Possible outcomes of acute inflammation Complete resolution Little tissue damage Capable of regeneration Scarring (fibrosis) In tissues unable to regenerate Excessive fibrin deposition organized into fibrous tissue Abscess formation occurs with some bacterial or fungal infections Progression to chronic inflammation

6. Outcomes Resolution The complete restoration of the inflamed tissue back to a normal status. Inflammatory measures such as vasodilation, chemical production, and leukocyte infiltration cease, and damaged parenchymal cells regenerate. In situations where limited or short lived inflammation has occurred this is usually the outcome. Fibrosis Large amounts of tissue destruction, or damage in tissues unable to regenerate, can not be regenerated completely by the body. Fibrous scarring occurs in these areas of damage, forming a scar composed primarily of collagen. The scar will not contain any specialized structures, such as parenchymal cells, hence functional impairment may occur.

7. Outcomes Abscess formation A cavity is formed containing pus, an opaque liquid containing dead white blood cells and bacteria with general debris from destroyed cells. Chronic inflammation In acute inflammation, if the injurious agent persists then chronic inflammation will ensue. This process, marked by inflammation lasting many days, months or even years, may lead to the formation of a chronic wound. Chronic inflammation is characterized by the dominating presence of macrophages in the injured tissue. These cells are powerful defensive agents of the body, but the toxins they release (including reactive oxygen species) are injurious to the organism's own tissues as well as invading agents. Consequently, chronic inflammation is almost always accompanied by tissue destruction.

8. Morphologic patterns of acute inflammation Inflammation is classified into two main morphologic groups A) Non suppurative inflammation B) Suppurative inflammation A) Non suppurative inflammation 1- Serous Watery, protein-poor effusion (e.g., blister) and contain few leukocyte.

9. BLISTER, “Watery”, i.e., SEROUS

10. Serous

11. Organ: Pericardium Diagnosis: Fibrinous Inflammation 2-Fibrinous Exudation of fluid rich in Fibrin

12. ACUTE FIBRINOUS PERICARDITIS

13. Patterns (cont ’ d) 3-Catarrhal- involve mucous secreting surfaces, fibrin and protein exudate mixed with mucus as in common cold affecting nasal passages . 4-Membranous(pseudomembranous): false membrane formed by exudate adherent to underlying mucous surface e.g. diphtheria. 5-Hemorrhagic: sever inflammatory exudate associated with damage to capillaries as in hemorrhagic pancreatitis 6-Gangrenous : The acute inflammation is complicated by superadded death and putrefaction of the tissues

14. B) Suppurative inflammation Characterized by purulent exudate containing large numbers of PMN which is localized or diffuse 1- Localized Abscess: cavity full of pus commonly due to Staph. Aureus infection Special types of abscesses 1.Boil(Furuncle):small abscess related to hair follicle or sebaceous glands 2. Stye : Abscess in the eye lid related to eye lashes 3. Carbuncle: multilocular abscess in the skin and subcutaneous tissue discharging pus through numerous openings

15. PUS = PURULENT ABSCESS = POCKET OF PUS

16. Abscess

17. 2-Diffuse suppurative inflammation : a. Phlegmonous inflammation of hollow organ: e.g. acute suppurative appendicitis b. Diffuse suppuration in a body cavity : e.g. suppurative pleuritis and meningitis c. Collection of pus in the lumen of an organ : e.g. Empyema of the gall bladder d. Cellulitis: inflammation of connective tissue, Panniculitis inflammation of subcutaneous tissue

18. Empyema of the gall bladder

19. Redness of the left foot due to cellulitis

20. Sequence of acute inflammation Ulceration(e.g. Peptic ulcers of the stomach or duodenum and diabetic ulcer of the legs ) Necrotic and eroded epithelial surface Underlying acute and chronic inflammation Trauma, toxins, vascular insufficiency

21. Peptic ulcer of the stomach

22. Fistula :communication between two organs (epithelial surfaces) or organ and surface. Sinus : Blind ended track from a cavity to the surface e.g. Pilonidal sinus . Bacteremia , Toxemia , Septicemia Pyemia : Septic emboli in blood stream arrested in different organs causing multiple small pyemic abscesses . Sequence of acute inflammation

23. FOREIGN BODY REACTION (PILONIDAL SINUS)

24. Small cortical pyemic abscesses

25. Continuous assessment Focal collection of pus is called   A) Abscess . B) Ulcer . C) Scar . D) Fistula