Cellular Pathology Flashcards
name 2 chemical mediators of inflammation derived from cells.
histamine
prostaglandins
name 2 chemical mediators of inflammation from the plasma.
heparin, plasmin
complement proteins
what is oedema?
increased leaking of fluid through permeable capillaries into the interstitial space due to oncotic or hydrostatic pressures.
what is exudate?
any fluid that filters slowly from the circulatory system into lesions or inflamed areas, normally rich in proteins.
what is transudate?
not due to inflammation, liquid that has passed through a membrane especially through the wall of a capillary, has a lower protein content and lower cell count than exudate.
what cells are involved in acute and chronic inflammation?
neutrophils, mast cells, eosinophils, basophils
lymphocytes, macrophages
what are the stages of healing and repair?
inflammation
proliferation
maturation
what is healing by primary intention?
wound involves epidermis and dermis without total dermal penetration, wound edges can be brought together with sutures or tape.
what is healing by secondary intention?
wound is allowed to granulate and contract and epithelialise by itself- for wider, deeper wounds.
what are the stages of bone healing?
haematoma
fibroblast inflammatory response-granulation
chondroblasts from hyaline cartilage
woven bone
lamellar bone- cancellous bone remodelled to compact
what is Virchow’s triad?
stasis/turbulence of blood flow
hypercoagulability
endothelial injury
what is an embolus?
circulating bolus of matter- detached from an original source
what is a thrombus?
matter that can cause a clot to form in a blood vessel
what is an infarct?
localised area of ischaemic necrosis
what is a haematoma?
collection of blood beneath an epithelium or membrane due to extravasation.
what is hyperaemia?
increased redness due to perfusion
what are petechiae?
smaller sub dermal collections of blood, caused by capillary haemorrhage e.g. puerperic rash, vasculitic
what pharmacological interventions can be used for the treatment of arterial thrombosis?
LMWH- Dalteparin
TPA - tissue plasminogen activator- alteplase
how can venous thrombosis in a hospital patient be avoided?
encouragement of early mobilisation and graduated compression stockings have been proven to reduce the risk of thrombosis.
atheroma affects mainly which layer of the blood vessel wall?
tunica intima
describe the stages of development of an atheromatous plaque
endothelial dysfunction/damage-espression of adhesion molecules- monocyte recruitment- macrophages and inflammatory cells- LDL ingested and oxidised by macrophages- foam cells- fatty streak formation in intima- growth into plaque of fatty deposition- release of growth factors causes smooth muscle growth in intima and fibrous tissue cap over plaque.
main risk factors for atheroma development
hypertension diabetes dyslipidaemia smoking genetic susceptibility (familial hypercholesterolaemia)
what are the causes of bowel infarction?
bowel obstruction- volvulus
mesenteric ischaemia- thromobosis
can cause peritonism and septicaemia.
consequence of atheroma in aorta
aneurysm, cerebrovascular accident, iliac thrombosis
consequence of atheroma in the coronary arteries
angina, MI
consequence of atheroma in renal arteries
renal artery stenosis- hypertension
renal failure
consequence of atheroma in cerebral arteries
berry aneurysm
CVA
what are the different types of aneurysm?
true aneurysm- involves all three layers of the arterial wall
false aneurysm- collection of blood leaking completely out of an artery or vein but confined next to the vessel by surrounding tissue (adventitia)- extravascular haematoma communicating with intravascular space
saccular or spherical
what causes dilatation of a vessel wall?
atherosclerosis erodes the vessel wall making it less flexible and weakening it- inflammation, oxygen radicals, muscle cell apoptosis- high flow and pressure
using Laplace’s law explain why an enlarging aneurysm is dangerous?
a narrower lumen has increased wall tension- this means more flow will be forced into the wider and less tense aneurym- causing it to enlarge.
what are the main features of prokaryotes?
single circular chromosome no nuclear envelope plasmids cell walls (except mycoplasma) 70s ribosomes no organelles can be flagellated
list 4 commonly used techniques to identify and classify bacteria associated with an infection.
growth plate culture- maconkey agar- lactose fermenter. urease etc.
Gram staining using crystal violet
microscopy- shape and motility of bacterium
genetic sequencing and PCR- rRNA or DNA analysis.
what is the causative agent in Whooping cough and name its staining and shape.
Bordetella Pertussis- Gram negative coccobacillus.
