Homeostasis, Haemorrhage and Shock Flashcards
what is the aim of the immediate response to blood loss
stop the bleeding
what is the aim of the short term response to blood loss
restore blood pressure
what is the aim of the long term response to blood loss
replace blood constituents e.g plasma proteins and blood cells, primarily rbcs
what is the aim of the medium term response to blood loss
restore fluid volume
haemostasis
stopping blood flow
what are the three components involved in the immediate response
vascular response
platelet response
plasma response (coagulation)
what occurs during the vascular response of haemostasis (immediate response)
contraction of blood vessels (myogenic response) and vasocontrictors (humoral)
what occurs during the platelet response of haemostasis (immediate response)
turbulent blood flow sees platelets coming into contact with blood vessel wall
they clump together (aggregate) and release chemicals that cause further aggregation(positive feedback ) forming the platelet plug
what occurs during the coagulation response of haemostasis (immediate response)
coagulation system sees formation of blood clot through activation via the intrinsic or extrinsic pathway
how is a blood clot destroyed once it has served its purpose
fibrinolysis via the fibrinolytic system producing plasmin which degrades fibrin
what receptors detect a fall in blood pressure
arterial baroreceptors
how is fluid volume restored in the medium term response
increasing fluid intake, decreasing fluid loss in kidneys, shifting interstitial fluid back into bvs
what is shock characterised by
inadequate blood flow to tissues
hypovolaemic shock
decreased ECF volume due to haemorrage, sweating, diarrhoea etc
cardiogenic shock
heart fails as a pump
