General pathology :::::::1.Hyperplasia is an increase in the number of cells in an organ or tissue, usually resulting in increased volume of the organ or tissue.
2. Hypertrophy refers to an increase in the size of cells, resulting in an increase in the size of the organ.
3. Atrophy is the shrinkage in the size of the cell by loss of cell substance.
4. Metaplasia is defined as a reversible change in which one adult cell type (epithelial or mesenchymal) is replaced by another adult cell type.
5. Cell swelling is the earliest sign of a reversible cell injury.
6. Free radical is a chemical species that have a single unpaired electron in an outer orbit.
7. Necrosis is a spectrum of morphological changes that follow cell death in a living tissue largely resulting from the progressive degradative action of enzymes on the lethally injured cell.
8. Necrosis has six major type; coagulative, Caseous, Liquefactive, fibrinoid,gangrenous and Fat.
9. Apoptosis (Greek falling off) is defined as a pathway of programmed cell death that is aimed at a highly regulated intracellular programme in which cells destined to death by activated enzyme that degrade the cell's DNA and nuclear and cytoplasmic proteins.
10. Morphologically an apoptotic cell shows: a) cell shrinkage, b) chromatin condensation c) formation of cytoplasmic blebs and apoptotic bodies, d) phagocytosis by macrophages.
11. Apoptosis has two phases a) Initiation phase extrinsic and intrinsic pathways b)Execution phase c)phagocytosis of dead cell
12. Genes promoting apoptosis are: bax,bak,bim
13. Genes inhibiting apoptosis are bcl 2 family.
14. Initiator caspase are 8 & 9, while executioner caspases are mainly 3 & 6.
15. Dystrophic calcification is always seen in damaged tissues while metastatic calcification may occur in normal tissues whenever there is hyperplasia.
16. Inflammation is a complex reaction to injurious agents suchj as microbes and damaged, usually necrotic cells that consists of vascular responses, migration and activation of leukocytes, and systemic reactions.
17. Inflammatory response consist of TWO main components: vascular & cellular, and divided into TWO main patterns: Acute and Chronic.
18. Vasodilatation is one of the earliest manifestation of acute inflammation, if follows a transient vasoconstriction of arterioles lasting few seconds.
19. Increased vascular permeability leading to the escape of a protein-rich fluid (exudate) into the extravascular tissue in the HALL MARK of acute inflammation.
20. Formation of endothelial gaps in venules is the most common cause of vascular leakage.
21. Leukocytes Adhesion molecular families have a major classes: a) Selectins (E,L & P types), b) Integrins, c) Immunoglobulin family of adhesion molecules and d) Mucin like glycoproteins.
22. Selectins mainly involved in rolling of leukocytes, PECAM in transmigration and immunoglobulin family in adhesions.
23. Chemotaxis is defined as uni directional migration of leukocytes towards the site of injury under chemical gradient action.
24. Most important chemotactic agents are C5a,LTB4 and bacterial products.
25. Major opsonins are: C3b & Fc fragment of IgG proteins
26. H202-MPO-Halide systein is the most efficient bactericidal system in neutrophils.
27. Chediak-Higashi Syndrome is an autosomal recessive condition characterized by failure of fusion of phagosome with lysosome.
28. Chronic granulomatous disease of childhood results from inherited defects in the components of NAPDH oxidase which generates superoxide, leading to body infections.
29. Vasoactive amines are histamine and serotonin which are the main players of early inflammation.
30. Plasma Proteins are: Complement system proteins, clotting system and fibrinolytic system.
31. Prostaglandins are vasodilators.
32. MAC (C5B6789) is the membrane attack complex, which finally kills the bacteria.
33. Activated Hageman factor initiates FOUR systems involved in inflammatory responses Kinin, Clotting, fibrinolytic and complement system
34. SRS-A (slow releasing substance of anaphylaxis) constitutes LTC4, LTD4 & LTE4 promote vasoconstriction, bronchospasm & increased vascular permeability.
35. Lipoxins are bioactive products generated from transcellular biosynthetic mechanisms involving neutrophils and platelets.