ATHIROSCLEROSIS (Blocks in arteries)

It is a disease in which arteries wall get thickened due to invasion and accumulation of white blood cells. It is known as fatty streaks. These accumulations contain both living and dead WBCs, cholesterol and triglycerides.  Inflammation takes place in such spots.

 Atherosclerosis and lipoproteins

The remnants include calcium, other crystalline materials and plaque at the outermost. The fatty streaks reduce the elasticity of the artery wall. In spite of this blood flow remains good for pretty long time. The artery bulges in the spots where fatty streak formed.

The wall stiffening increases pulse pressure eventually. That is the stage of developing malfunction in the body. It is only a syndrome, indicating a set of known signs.

 

 The progression of atherosclerosis (narrowing exaggerated)

This syndrome is promoted by LDL, plasma proteins, cholesterol and triglycerides in arterial blood vessels. HDL have the capacity to remove fatty streaks. When it does not happen it takes the form of a disease.

Atherosclerosis is a chronic disease that remains in the body for decades. They are two types, stable and unstable.  The stable lesion consists of smooth muscle cells whereas the unstable lesion consists of foam cells. 

 Severe atherosclerosis of the aorta. Autopsy specimen.

The unstable fatty streak is vulnerable on the top and gets ruptured exposing the inner part to blood circulation. Collagen, structural protein gets into blood circulation. It results in blood clot.

 

 Micrograph of an artery that supplies the heart showing significant atherosclerosis and marked luminal narrowing. Tissue has been stained using Masson's trichrome.

The ruptured materials often causes complete block in smaller arteries leading to the death of tissues fed by arteries. When coronary artery gets blocked heart attack results. When brain artery gets blocked it results into stroke. When artery to the legs are blocked disease known as claudication in the form of pain while walking results.