Haemodynamic disorders Flashcards
haemodynamics=
movement of blood
fluid homeostasis requires (3)
vessel wall integrity
osmolarity
maintenance of intravascular pressure
extravasation=
movement of water or blood across the vascular wall
what ensures capillaries don’t collapse
pressure
edema=
an increase of fluid in the interstitial space,
hydrostatic pressure—>
drives fluid out of the tissue
colloid osmotic pressure=
increased protein concentration
what does colloid osmotic pressure result in
pulls water back into vessels
things causing edema= (3)
Increased vascular pressure/volume
decreased plasma protein content
change in endothelial cell function
hydrothorax=
edema in the thoracic cavity
hydropericardium=
edema in the pericardial cavity
common causes of decreased osmotic pressure (reduced plasma proteins)
liver cirrhosis
malnutrition
sodium retention causes
increase in hydrostatic pressure
haemorrhage=
extravasation of blood
pathological thrombosis=
formation of blood clot within the vessel (attached to wall)
embolism
dislodged thrombosis travelling away from original site
what is the % of blood volume that causes hypovolemic shock
above 20%
three phases of haemostatic process
hemorrhage
thrombosis
fibrinolysis
types of haemorrhage (3)
petechiane
Purpura
bruises/ Ecchymosis
petechiane=
minute hemorrhage (1-2mm) of skin and mucosa
purpura=
small haemorrhage (3-5mm) trauma or vasculitis
bruises/ Ecchymosis=
subcutaneous hematoma
three main factors causing thrombosis
endothelial injury
abnormal blood flow
hyper-coagulability
what is a thrombi formed from
platelets RBC neutrophils Lymphocytes Fibrin
what holds the thrombi together
fibrin
what causes arterial thrombi
platelet driven, atherosclerosis which is susceptible to damage
what causes venous thrombi
changes in blood flow (stasis)
what are nearly all emboli caused by
thromboembolism
thromboembolism=
dislodged thrombus
hyperaemia=
increased blood flow in
congestion=
reduced blood flow out
reactive hyperaemia=
local vasodilation in response to oxygen debt or accumulation of metabolic waste
active hyperaemia=
vasodilation in response to activation (exercise)
congestion is usually cause by
impaired venous return
what can impaired venous return be caused by (2)
- physical obstruction of veins
- or failure of the heart to pump blood away
circulatory shock caused by
systemic hypo-perfusion leading to reduced delivery of O2 and nutrients
hypo-perfusion =
lack of blood flow
three things circulatory shock is associated with
hypotension
hypoperfusion
cellular hypoxia
cardiogenic shock=
failure of heart to pump sufficient blood
hypovolemic shock=
loss of blood or plasma
reasons for cardiogenic shock
MI
Arrhythmia
PE
ect
septic shock=
systemic infection
commonly bacterial in blood stream
neurogenic shock=
severe damage to the CNS
effect of neurogenic shock
loss of systemic stimulation to blood vessels leading to wide spread vasodilation
anaphylactic shock=
severe allergic reaction—> cytokines/ histamine –> vasodilation and hypoperfusion
how can septic shock occur (6 steps)
bowel perforation bacteria enters blood stream leaking vessel impaired blood flow septic shock multiple organ dysfunction
