Tissue damage and Inflammation Flashcards

Question

pseudodrusen on FAF

Answer 1

Reduced signal from blocking and increased the signal from RPE distress.

Answer 2

1. necorsis = death of a group of cells, always pathological 2. apoptosis = programmed cell death

Answer 3

1. hydropic swelling - cell becomes swollen, usually 2nd to trauma 2. atrophy - decrease in cell size and number

Answer 4

 Reaction to injury be it physical, chemical, infective, immunological  Vascular phase followed by cellular phase

Answer 5

Classic signs: redness, heat, swelling, pain, loss of function  Hyperaemia: initial vasoconstriction then dilation  Vasodilation slows blood flow causing cells to move to the sides (margination)  Exudation: protein-rich fluid moves into interstitial fluid (dilutes toxins)  Leucocyte migration for phagocytosis: extravasation and chemotaxis  Non-adaptive, no memory, non-specific

Answer 6

lasts 1-2 days resolve (if no tissue destruction and exudate is removed), suppurate, repair with organisation/scarring (if the exudate persists), progress to chronic inflammation. If tissue is destroyed, regeneration can occur if the lost cells are labile or stable. If permanent cells are lost, a vascularised connective tissue scar forms

Answer 7

 Histamine: from degranulated mast cells. Increases vascular permeability (C3a and C5a) and vasodilation of venules. Short-term effect (5-15 minutes)  Kinins: more prolonged venule and capillary vasodilation response  Prostaglandin: dilates arterioles. More persistent response (4-24 hours)

Answer 8

eosinophil

Answer 9

Bonds are established (by selectins on endothelium and integrins on neutrophils) between endothelium and white cells following margination (normally, both neutrophils and endothelium have negative charge and so do not contact)

Answer 10

Platelet activating factor activates neutrophils and induces beta-integrins expression on their cell membranes which further promote adhesion with the endothelium

Answer 11

ransmigration of the neutrophils between endothelial cells then occurs, stimulated by IL-8

Answer 12

following transmigration, the movement of cells is mediated by chemotaxis, along the concentration gradient of chemotactic agents. It is the directional and purposive movement of phagocytic cells towards areas of injury/invasion

Answer 13

o Reception of signals o Response to signals (transduction)

Answer 14

o Cytokines from other leucocytes o Complement components (C5 and C5a) o Arachidonic acid derivatives (eicosanoids eg. leukotrienes and prostaglandin E) o Pathogens o Lymphokines (produced by T helper lymphocytes)

Answer 15

Once within the injured tissue, leucocytes can undertake phagocytosis  Recognition, aided by opsonisation o Opsonins: IgG and C3b  Bacterium/foreign object engulfed by a phagosome

Answer 16

Phagosome fuses with lysosome: associated with the “respiratory burst” of metabolic activity producing hydrogen peroxide

Answer 17

Within tissues, monocytes undergo enlargement, increased lysosome numbers, Golgi and ER development

Answer 18

 Increased phagocytic capacity  Production of hydrolytic enzymes, pyrogen and interferon (blocks translation of viral mRNA)  Stimulates fibroblast proliferation and further polymorph production  Lymphocytes activating factor (IL-1) stimulates T helper cells

Answer 19

 Stimulated by C3b  Capable of cell division  Contribute to antigen presentation  Can fuse to form multinucleated giant cells (increased phagocytic activity)  Epithelioid cells within granulomas are derived from a single macrophage (increased secretory capacity)

Answer 20

“mutton-fat” KPs) are composed on macrophages compared to non-granulomatous KPs which are mainly lymphocytes and PMLs

Answer 21

 Involved in acute inflammation, phagocytosis, clotting, immune and hypersensitivity reactions (C3a and C5a are anaphylatoxins)

Answer 22

 Classical and alternative pathways are both stimulated by plasmin

Answer 23

 C3a and C5a increases vascular permeability as above. C5a is 1000 times more active  C5b joins with C6, C7, C8 and C9 to form the membrane attack complex which is capable of cell lysis

Answer 24

Factor XII (Hageman factor) of the clotting cascade has a central role in activating 3 systems operating within plasma

Answer 25

 Kinin system (via activating prekallikrein) to produce potent vasodilators  Clotting cascade (via stimulating factor XI)  Complement system (via activating plasminogen to plasmin) All three have positive feedback loops to activate more Hageman factor

Answer 26

 Response to persistent pathogen/irritant (need not be infectious)  NB: acute phase does not need to be prolonged (eg. in TB it is very brief)  Cellular response predominates: mixed proliferation and destruction

Answer 27

 failure of acute inflammatory neutrophils to clear the inciting agent, meaning macrophages take over  Derived from macrophages and their lineage  Caseation is a feature of tuberculous granuloma

Answer 28

 Inner core of macrophages and epithelioid cells with increased secretory capacity  Core surrounded by layer of activated macrophages (containing ingested microoganisms) and T lymphocytes  Outer layer containing fibroblasts and multinucleated giant cells

Answer 29

 Response to breakdown of endogenous materials (eg. chalazion: reaction to rupture of a blocked meibomian gland duct releasing irritant keratin)  Response to exogenous non-biological materials ie. foreign body  Mainly mycobacteria eg. TB or leprosy and fungi  Unknown eg sarcoidosis (non-caseating)

Answer 30

characterised by lymphocytes and plasma cells  Behcet’s disease  Multiple sclerosis

Answer 31

 Response to inflammation promoted by fibrin and its degradation products

Answer 32

Endothelial activation (within 24 hours)  Endothelium retracts and nucleoli enlarge  Endothelial basal lamina broken down by plasminogen activator  Produced by fibroblasts, macrophages and others

Answer 33

 Sprouts from post-capillary venules and capillaries  Lumen formation and anastomosis of blind channels

Answer 34

deposition of ECM and laminin and basal lamina formation

Answer 35

 Vasodilation  Vascular permeability of neighbouring vessels  Stromal oedema

Answer 36

Direct killing of cells ( free radicals release, ionic forms of hydrogen and hydroxyl result in a break in DNA structure) Cellular DNA changes Damage to blood vessels leading to secondary ischaemic necrosis

Answer 37

Necrosis of sclera ( can occur with mitomycin C) Dry eye syndrome ( usually occur with doses of 60-70gy) Punctate epithelial erosion Cataracts

Answer 38

( may take up to 20 years after exposure before developing cataract) Young patients more susceptible as more active lens cells growing . The lens is the most radiosensitive structure with an average latent period of 2-3 years.

Answer 39

Slowly progressive Microangiopathic changes can mimic diabetic retinopathy. 4) The delay is usually 2-3 years for radiation optic neuropathy

Answer 40

Caused by shockwaves from trauma Induces outer retinal sheen-like whitening OCT findings Photoreceptor and retinal pigment epithelium (RPE) disruption Vision can go down to 6/60

Answer 41

Disruption to Bruch's membrane/RPE Associated with subretinal bleeding Usually around optic disc or periphery (occasionally in the macula) Choroidal neovascularization (CNV) can grow at rupture site.

Answer 42

Traumatic vitreomacular traction Submacular haemorrhage from choroidal rupture Severe commotio retinae

Answer 43

Caused by high-velocity projectile injury to the orbit Causes choroidal and retinal damage Can present with subretinal, retinal and vitreous haemorrhage Over time retinal scars will form

Tissue damage and Inflammation Flashcards

(69 cards)