cirulation Flashcards
where are platelets produced
bone marrow
platelet precursor cell
megakaryocyte
how are platelets produced
bud off from cycloplasmic extension
what type of blood does thrombus form in
flowing
process from clot to thrombus
- clot forms in stationary blood
- continued bleeding
- vasoconstriction
- thrombus formed
what type of blood do clots form
stationary
what do clots look like and what are they made from
red
fibrin and RBC through clotting cascade
what do thrombi look like and what makes them
pale cream
fibrin and platelets
clotting cascade
clotting factors turn prothrombin into thrombin
thrombin mixes with soluble fibrinogen to make insoluble fibrin
what are clotting factors
many are serine proteases
process after an injury
- plasma mixes with interstitial collagen fibres activating clotting factors
- smooth muscle releases tissue factors, also triggering clotting cascade
- exposed platelets to interstitial collagen fibres stick togeter and plug the gap
what happens after clot/ thrombus formation
angiogenesis and granulation
how are clots/thrombi removed
plasminogen turns to plasmin which cuts the fibrin
Virchow’s triad (causes of thrombi)
change in intimal surface- a cut
change in pattern of blood flow
change in blood constituants
pathological thrombi are often made from
layers of clot and thrombi
pathological thrombi ultimately cause
ischaemia- decreased blood flow
ischemia can lead to
hypoxia
then death of tissue- infarct
then necrosis
bloop pressure is monitored by
2 carotid bodies and 2 carotid sinuses
BP and HR during shock
low BP due to lack of blood
high HR to try and compensate
hypovolemic shock
blood loss causing:
blood vessel collapse
decreased venous pressure
less blood in right heart
so less in lungs- little O2 transport
carotid sinuses sense decreased BP and trigger sympathetic NS
-adrenalin, increased HR, breathing and sweats
consequences of shock
brain dies due to lack of O2
icheamic injury
