ICS Flashcards
what is a granuloma
epithelioid histocytes (macrophages) lymphocytes release ACE caseating - necrosis in middle eg. TB noncaseating eg. crohn's, sarcoidosis
transudate content
increased hydrostatic pressure low protein <3g LDH low clear low cell count eg. congestive heart failure
exudate content
increased vascular permeability high protein >3g LDH high cloudy high cell count eg. pneumonia, lung cancer
4 outcomes of acute inflam
resolution
suppuration
organisation/repair
progression
neutrophil emigration/extravasation
migration - neutrophils migrate to plasmatic zone due to increased viscosity and reduced flow
adhesion - neutrophils adhere to vascular endothelial cells of vessel
extravasation/emigration - neutrophils pass through cells into basal lamina then vessel wall
diapedesis - RBC may also move through passively which indicates serve vascular injury/damage
3 substances that attract vascular smooth muscle cells to migrated from media to intima
PDGF endothelin 1, interleukin 1
LDL and inflam leads to
endothelial dysfunction
LDL gets into intima layer and…
becomes oxidised by free radicals. endothelial cells respond by attracting monocytes (macrophages once in tissue fluid)
macrophages ingest oxidised LDL and become
foam cells which eventually rupture and release oxidised substances and fats = increased inflam
what is atheroma composed of
vascular smooth muscle cells, collagen, (first 2 cause new growth)
macrophages
lymphocytes
elastin
how does aspirin work in atherosclerosis
reduced platelets binding
how do statins work in atherosclerosis
lower blood levels of LDL hence reducing production of foam cells
4 possible fates of thrombi
dissolve/resolve on its own
embolise
recanalization - intima cells proliferate to accommodate
organisation - scar
common cause arterial thrombus
atheroma increased pressure mainly platelets = Stroke MI treat with antiplatelet eg. aspirin
common cause venous thrombus
stasis decreased pressure mainly RBC = DVT PE treat with anticoagulant eg. warfarin
where are venous thrombi commonly formed
valves
describe hypersensitivity 1
antigen presented on IgE of mast cell
eg. anaphylaxis
describe hypersensitivity 2
antibodies and antigen on cell surface
eg. blood transfusions, haemolytic anaemia, goodpastures
describe hypersensitivity 3
antigen and antibody complex
complement activated
neutrophil infiltrates
eg. SLE, hypersensitivity pneumonitis, RA
describe hypersensitivity 4
TH1 release cytokines that activate macrophages
eg. TB, MS, graft rejections, contact dermatitis
cell size in necrosis
enlarged (swelling), disrupted plasma membrane, adjacent inflam
cell size in apoptosis
reduced/shrinkage
intact plasma membrane
no adjacent inflam
5 diff between benign and malignant
benign - low mitotic energy, slow-growing, better blood supply, less necrosis/ulceration, no BM invasion, exophytic (grows out)
malignant - high mitotic energy, fast growing, poorly vascularised, necrosis/ulceration, invades BM, endophytic (grows in)
define hypertrophy
increasing cell size w/o cell division
define hyperplasia
increasing cell number by mitosis (only in dividing cells)
define atrophy
decrease size of organ/cell
define dysplasia
morphological changes of cells progressing to cancer
define metaplasia
one fully differentiated cell becomes another (baretts oesophagus)
define neoplasia
lesion of abnormal growth (requires nuclei)
define tumour
any abnormal swelling
define carcinogenesis
transformation of normal cells to neoplastic (permanent genetic changes)
cancer beginning ‘Lipo-‘ is
adipocytes
cancer beginning ‘Rhabdo-‘ is
satiated muscle
cancer beginning ‘Sarco-‘ is
connective tissue
cancer beginning ‘Leiomy-‘ is
smooth muscle
cancer beginning ‘Chondro-‘ is
cartilage
cancer beginning ‘Osteo-‘ is
bone
cancer beginning ‘Leuk/Lymph-‘ is
lymphatics
cancer beginning ‘Carc-‘ is
epithelial
which cancer doesn’t metastasise
basal carcinoma
most common adenocarcinoma?
lung
adrenaline function
stimulates alpha 1 receptors = vasoconstriction, increase BP
beta 2 recep = bronchoconstriction
antihistamine function
competitive inhib, block histamine from binding = vasoconstrict, decrease swelling, increase BP
hydrocortisone function
glucocorticoid receptor agonist = protein catabolism
IgE role in anaphylaxis
stimulates mast cells to rapidly release histamine and inflam markers which causes airway breathing circulation compromise
anaphylaxis symp
itching, hives (urticaria), angio-oedema, eye lip swelling, SOB, wheeze, tachycardia, lightheaded
test for diag of anaphylaxis
serum mast cell tryptase within 6 hrs
define anergic t cells
have receptors which bind to self antigens and become inactive
define clonal deletion
t cells in thymus, bind to self proteins and destroyed by apoptosis
define clonal inactivation
t cells react to self antigens and become unresponsive (thymus and lymph periphery)
define attenuated vaccine
weakened living form eg. TB MMR
define subunit vaccine
part of pathogen introduced eg. Hep B HPV
define inactivated vaccine
dead form of pathogen eg. Hep A, flu
define toxoid vaccine
toxins = immune against affects but not actual pathogen
astrazeneca is …?
Pfeizer and moderna is ….?
astra = viral vector
p and m = nucleic acid/mRNA
