3血液循环.pptVIP

cardiac infarction (Irregular, or map-shaped) Hemorrhagic infarct of intestine (Loops) mesentery HISTOLOGY 1. The dominant histologic characteristic of infarction is Ischaemic coagulative necrosis. 2. Inflammatory response begins to develop along the margins of infarcts. 3. Most infarcts are ultimately replaced by scar. 4. The brain is an exception to these generalizations, ischemic tissue injury in the central nervous system results in liquefactive necrosis. 5. Septic infarcts : form abscess. Infarction of kidney(white) Rim of inflammatory response Areas of infarction Infarction of kidney Cardiac infarction Red infarction of lung Hemorrhagic infarct of intestine Cerebral infarct (liquefactive necrosis) Cerebral infarct when bacterial vegetations from a heart valve embolize or when microbes seed an area of necrotic tissue. In these cases the infarctis converted into an abscess Septic infarctions FACTORS INFLUENCING DEVELOPMENT OF INFARCT Vascular occlusion can have no or minimal effect, or can cause death of a tissue or even the individual. The major determinants of the eventual outcome include: Nature of Vascular supply Rate of development of occlusion Vulnerability to hypoxia Oxygen content of blood SUMMARY -- Infarction Infarcts are areas of ischemic, usually coagulative, necrosis caused by occlusion of arterial supply or less commonly venous drainage. Infarcts are most commonly caused by formation of occlusive arterial thrombi, or embolization of arterial or venous thrombi. Infarcts caused by venous occlusion, or in loose tissues with dual blood supply, are typically hemorrhagic (red) whereas those caused by arterial occlusion in compact tissues are pale (white) in color. Duplicate exercise Term statement congestion, heart failure cell, pulmonary brown duration, nutmeg liver, thrombosis, embolus, mixed thrombus, infarction, red infarct, white infarct. Question and answer 1.Pathological changes and types of infa