Chronic Inflammation & Repair 1 Flashcards
Describe how inflammation gets resolved.
-macrophage can lymphatic vessels remove the exudate
-inciting agent or substance is eliminated
-CT of affected tissue can still support epi cells
-damaged epi can regen on intact BM
Describe abscess formation.
-localized collection of pus in a cavity formed by disintegration of tissue
-caused by bacteria or other inf agents/foreign body
-surrounded by fibrous capsule
>ex of chronic inflam
-consists of purulent/suppurative exudate
>ex of liquefaction necrosis
>fluid collection of necrotic & inflam cells
-occurs when acute inflam resp FAILS to rapidly elim inciting stim
-enzymes & inflam mediators LIQUIFY affected tissue & neutrophils to make pus
-form within FEW DAYS
-thick fibrous capsule can wall off exudate (weeks-months)
*antibiotics dont penetrate -> lance
Describe chronic inflammation.
-weeks, months, yrs
-chronic inflam cells
-tissue destruction
-attempts at healing
-occurs when acute inflam resp fails to elim stim
-repeated episodes of acute inflam
-resp to unique biochem characteristics/virulence factors in stim or microbe
Describe chronic inflammation examples of causes.
- Systemic mycoses
-crypto, histo, blasto - Intracellular bacteria
-mycobacteria, Rhodococcus - Protozoa
-toxoplasma, leishmania - Parasites
-Toxocara, Habronema - Foreign body
-grass seeds, splinters, suture, inj - Autoimmune disease
-allergic dermatitis (FAD)
Describe how chronic inflammation is characterized by.
persistence of inciting stim
1. Bacteria, mycoses, parasites *
-avoid/resist phagocytosis
-prevent fusion of lysosomes
-isolation (hide from IR) in pus [ex. Strep, staph]
2. Unresponsiveness to phagocytosis or enzymatic breakdown *
-ex: plants, suture
3. Altered immune resp
-autoimmune disease = altered adaptive IR to self aG w chronic inflam
-unidentified mech
4. Infiltration by mononuclear cells
-macrophages & lymphocytes (inflam & IR)
-other inflam cells: plasma, neutrophils, eosinophils
5. Extensive tissue injury & necrosis
6. CT replacement followed by fibrosis (attempt to repair)
Describe macrophages in inflammation.
-stimuli cont induce release of cytokines, chemokines, inflam mediators
-macrophage infiltration & activation
-cytokines made by macrophages & T cells amplify & prolong inflam
-activated macrophages in tissue are large w clear cytoplasm, eccentric nuclei ‘epitheliod’
Describe macrophages roles.
- Respond & migrate to inflam stim
- Remove injurious agents & cell debris (phagocytosis)
- Stim adaptive IR (lymphocyte)
- Cause further tissue damage
- Secrete growth factors to begin repair
>fibroplasia, angiogenesis
Describe multinucleate giant cells.
macrophage differentiate w time
-Collection of fused macrophages
-Langhans (peripheral nuclei) or foreign body type (central nuclei) *
>seen in granulomatous inflam esp when diff to elim cause of inflam (mycobacteria, fungi, foreign body)
Pictures of macrophages.
Describe monocytes in tissue macrophages.
-leave blood under physiologic conditions to pop tissues
-CT (histiocytes)
-liver (kupffer cells)
-lung (alveolar macs)
-LN
-spleen
-BM (osteoclasts)
-brain (microglial cells)
-skin (histiocytes)
Describe monocytes in infiltrating macrophages.
- M1 macs
-receptors that resp to inflam stim to cause migration, chemotaxis, phagocytosis
-stim to resp to & secrete cytokines
-resp for acute phase protein resp via cytokines (IL1/TNFa)
-present antigen/interact w TLC (link to adaptive IR) - M2 macs
-CT repair & fibroplasia *
Describe the different types of chronic inflammation.
- Granulomatous inflammation - diffuse & nodular
- Eosinophilic granuloma
- pyogranulomatous
- Lymphocytic
*can have mixture of cell types
Describe granulomatous inflammation.
-chronic inflam
-predominant cell = macrophage
>contains MNGC, lymphocytes, eosinophils, fibroblasts, fibrous tissue (collagen), necrosis
-due to persistence of foreign injurious agents
>tuberculosis (mycobacterium), fungi, myocardia, foreign body
-special stains to ID cause:
>mycobacterium spp = ziehl neelson stain acid fast
>fungi = periodic acid schiff stain - silver stains
Describe the two morphological forms of granulomatous inflammation.
- Diffuse (lepromatous) form (th2)
-diffuse accumulation of macrophages in tissue
-ex. Johnes disease - Nodular (tuberculoid) form (th1)
-tissue forms into nodular masses of inflam tissue
-nodules called ‘granulomas’
-ex. Tuberculosis
Describe more examples of granulomatous inflammation.
Describe feline eosinophilic granuloma.
Describe equine nodular collagenolytic granuloma.
Describe chronic pyogranulomatous inflammation.
-combo of neutrophil & macrophages
Describe chronic lymphocytic inflammation.
