HLI definitions Flashcards
Haemostasis
arrest of blood loss from damaged vessels
coagulation
formation of a fibrin clot in a blood vessel
thrombus vs clot
forms in vivo vs forms in static blood
thrombosis
pathological formation of a haemostatic plug in a blood vessel in the absence of blood loss
thromboembolus
a blockage in a blood vessel caused by a dislodged thrombus
Haemorrhage by rhexis
a substantial tear in a blood vessel or a tear in a heart chamber -> rapid escape of a substantial volume of blood
haemorrhage by diapedesis
escape of red blood cells one by one through minute or microscopically imperceptible defects in vessel walls
haemarthrosis
haemorrhage into a synovial joint
haemoptysis
coughing blood
haematemesis
vomiting of blood
haematochezia
passage of fresh blood in faeces (typically over the surface of stools)
dysentery
diarrhoea containing blood
meleana
diffuse, dark red-black discolouration of faeces due to upper alimentary tract haemorrhage or swallowing of blood from the respiratory tract
epistaxis
bleeding from the nose
hyphaema
haemorrhage into the anterior chamber of the eye
petechiae haemorrhages
tiny, pinpoint foci of haemorrhage, 1-2 mm in diameter
- petechiae are typically found in skin and on mucosal and serosal membranes
purpura haemorrhage
slightly larger haemorrhages ≥ 3 mm in diameter
ecchymoses haemorrhage
larger foci of haemorrhage, 2-3 cm in diameter; usually blotchy and of irregular shape
paintbrush haemorrhage
(or suffuse or suffusive) haemorrhages = linear or streaky haemorrhages, especially over serosal or mucosal membranes, as if a brush dipped in red paint has been hastily splashed across the tissues
what type of haemorrhages are visible but not palpable
petechiae, purpura, ecchymoses and paintbrush haemorrhages
haematoma and when seen
a palpable, discrete, space-occupying mass of clotted blood within tissues - largest volume of blood
- small haematomas are common at sites of difficult venipuncture
Haemorrhagic diatheses
clinical disorders of haemostasis characterised by a bleeding tendency
- haemorrhage may occur spontaneously or there may be excessive bleeding in response to minor trauma
thrombocytopathies
platelet function disorders
thrombopathia
absence or dysfunction of a signal transduction protein necessary for platelet release of dense granules and exposure of binding sites for fibrinogen