Colonic arteriovenous malformation (AVM) is one of the causes of lower GI bleeding. Unlike small vascular ectasia or angiodysplasia, colonic AVM tends to be solitary, large in size, and identified endoscopically as flat or as an elevated bright red lesion.n the case of the colon, wall tension refers to intramural tension, the pressure difference is that between the bowel lumen and the peritoneal cavity, and cylinder radius is the radius of the right colon. Wall tension is highest in bowel segments with the greatest diameter, such as the right colon.
This lack of signalling makes it harder for the immune system to locate and recycle dead cells which have died through necrosis than if the cell had undergone apoptosis. The release of intracellular content after cellular membrane damage is the cause of inflammation in necrosis. There are many causes of necrosis including injury, infection, cancer, infarction, toxins and inflammation. Severe damage to one essential system in the cell leads to secondary damage to other systems, a so-called cascade of effects. Necrosis can arise from lack of proper care to a wound site.
Coagulative necrosis is most commonly caused by conditions that do not involve severe trauma, toxins or an acute or chronic immune response. The lack of oxygen (hypoxia) causes cell death in a localised area which is perfused by blood vessels failing to deliver primarily oxygen, but also other important nutrients.