pathology formative 2 Flashcards
MI:what pattern of necrosis would you expect to find in the myocardium?
coagulative
how does coagulative necrosis appear? histological appearance
loss of cell detail but ghost outline of tissue architecture remains
coagulative necrosis found where
solid organ
what colour does coagulative necrosis appear in MI?
pale/white
occlusion of an end artery> cell death with very slight haemorrhage
why do cells swell during ischaemia?
loss of function of energy dependent membrane pump> sodium and water accumulate in cytoplasm
differences between necrosis and apoptosis
necrosis:
- sheets of cells affected
- associated inflammation
- cell swelling
- always pathological
- membrane breaks down
- diffuse/ random DNA cleavage
apoptosis:
- single cells affected
- no associated inflammation
- cell shrinkage
- pathological or physiological
- membrane intact
- internucleosomal DNA cleavage
why is swelling seen in an inflamed area?
chemical mediators are released> cause arterioles to dilate and endothelial cells to contract > spaces between endothelial cells
> dilation leads to inc hydrostatic pressure. within the capillaries and fluid is pushed out between the gaps into tissue spaces
> conc of protein within the tissue spaces is increased, osmotic pressure inc, pulls more fluid into the tissue spaces
functions of complement system
- kill bacteria by forming membrane attack complex which punches holes in membrane
- chemical mediators/ chemotaxis
- opsonisation
functions of macrophage
- phagocytosis
- secrete chemical mediators
- present antigens to immune system, initiating the immune response
- stimulate angiogensis
- induce fibrosis
- induce fever, acute phase reaction
what is a granuloma?
chronic inflammatory response
- collection of cells e.g. macrophages, giant cells, fibroblasts, lymphocytes
> surrounds and attempts to destroy difficult pathogens/particles
how do the 3 giant cells appear?
Langhans- nuclei around periphery
foreign body- nuclei arranged randomly
touton- nuclei arranged in a ring towards cell centre
what type of necrosis does Tuberculosis show?
caseous
> central zone of necrosis
amorphous, structureless, eosinophilic, granular
conditions in which granulomas are commonly seen?
syphilis leprosy fungal infection crohns disease chronic granulomatous disease TB sarcoidosis
eosinophils raised when?
allergic reaction
infection with large parasite
some tumours e.g. Hodgkins lymphoma
why can’t myocardium regenerate?
myocytes are permanent cells and no stem cells are present
which tissues must always heal with a scar?
skeletal muscle
neural tissue
cardiac
principle cellular constituents of granulation tissue
fibroblasts
endothelial cells/capillaries
local factors that can impair wound healing
poor blood supply local infection presence of foreign bods large amount of necrotic tissue poor surgical technique large size of wound
describe route of thrombi-embolism from leg veins to lungs
deep veins of calf iliac veins inferior vena cava right atrium right ventricle pulmonary artery
diff between thrombosis and clotting
thrombosis
- pathological
- inappropriate formation within a vessel
clotting
- physiological
- controls bleeding when vessels are severed
- occurs outside vessels
Virchows triad
Abnormal flow
Abnormal blood constituents
Abnormal vessel wall
mechanisms of death with PE
respiratory compromise> non perfused but ventilated area of lung> hypoxaemia
haemodynamic compromise- incr resistance to pulmonary blood flow due to obstruction of pulmonary vessels > Right sided heart failure
complications of abdominal aortic aneurysm
- rupture and haemorrhage
- thromboembolism to legs causing acute ischaemia
- aortic occlusion or rupture
xanthelasma caused from which condition?
its weird blobs on their eyes
- hyperlipidaemia
- hypercholesterolaemia
why can some organs only undergo hypertrophy and not hyperplasia?
Permanent tissues can only undergo hypertrophy as these cell populations have little or no replicative potential
causes of ventricular hypertrophy
- systemic hypertension
- valvular heart disease (aortic stenosis/ a/mitral regurg)
- ischaemic HD
- hypertrophic cardiomyopathy
- exercise
causes of atrophy
- inadequate nutrition
- disuse
- denervation
- inadequate blood supply
- loss of endocrine stimulation
- persistent injury
- aging
- pressure
what happens in metaplasia
stem cells within the tissue are reprogrammed and express diff genes> switch from producing one cell type to another (diff phenotype)
- eliminated and replaced
progression meaning in cancer
step wise accumulation of mutations
human chorionic gonadotropin associated cancer
trophoblastic tumours
nonseminomatous testicular tumours
calcitonin is a tumour marker for which cancer?
medullary carcinoma of the thyroid
catecholamine and metabolites - a tumour marker for which cancer?
pheochromocytoma
a- fetoprotein is a tumour marker for which cancer?
liver cell cancer
nonseminomatous germ cell tumour of testes
carcinoembryonic antigen is a tumour marker for which cancer?
colon cancer
prostate specific antigen is a tumour marker for which cancer?
prostate cancer
CA125 is a tumour marker for which cancer?
ovarian cancer
CA-19-9 is a tumour marker for which cancer?
pancreatic cancer
most common type of cervical cancer?
squamous cell carcinoma
known malignancy and hypercalcaemia. high levels of parathyroid hormone related protein. which likely neoplasm?
bronchial squamous cell carcinoma
sequence of events in haemostasis
arteries contract
platelet plug forms
fibrin filaments accumulate and trap RBCs
