Infarction Flashcards
Stages of infarction
1) 0-12hrs early stages of cell death-> coagulation necrosis-> ghost cells produced
2) 12-14hrs necrotic muscle fibres apparent (eosinophilic) microscopically
3) 24-72 hours-> acute inflammation reaction to necrotic tissue->neutrophilic-> pale and yellow
4) 3-14 days-> macrophagic removal of deadbris and vasuclar granulation tissue formation-> hyperaemia around dead muscle
5) 14-21 days-> fibrous granulation tissue formation
6) 21-56 days->% scar formation and cicatrisation
Infarction definition
Death of tissues due to lack of O2 following abrupt cessation of arterial supply or venous drainage
Damage through ischaemia
Results in coagulative necrosis at the target region
Complications of mycardial infarction
Early Sudden death due to cardia dysrhythmia Sudden death due to acute LV failure Rupture of myocardium-> haemopencardium Rupture of papillary muscle-> acute valve failure-> LVF Late: Chronic LVF Ventricular aneurysm
Arterial infarction-> gangrene
Infarct of peripheral limb
Foot and leg most common
Due to either-> thrombus occulding atheromatous iliofemoral artery or thromboembolism from left side of hear
-> graft bypass
Arterial infarct-> renal
Usually due to embolism on left side of heart
Wedge shaped
Pale area with hyperaemia around
Cerebral infarct
Liquefitive necrosis-> cell completly digested by enzymes
Caused by-> Atheroma, thrombosis, in extra cerebral arteries, embolic, watershed,
Venous infarction, definition
Entire venous drainage from a tissue or organ is blocked-> tissue become massively suffused by blood
Eg valvulus, hernia strangulation, torsion of spermatic chord
Stages of venous infarction
1) veins become obstructed
2) tissues become congested, venuls and capillaries enlarged by blood that can’t escape
3) pressure in capillaries and venues rises-> may rupture with leakage of blood, arteries blood can’t enter-> hypoxia
4) tissue becomes congestive and coagulativly necrotic
