Cerebrovascular accident (CVA) is the medical term for what is commonly termed a stroke. It refers to the injury to the brain that occurs when flow of blood to brain tissue is interrupted by a clogged or ruptured artery, causing brain tissue to die because of lack of nutrients and oxygen. Causes and symptoms
Arterial blood carries oxygen and nutrients to the cells of the body. When arteries are unable to carry out this function due to rupture, constriction, or obstruction, the cells nourished by these arteries die. There are two forms of stroke, ischemic, which is caused by a blocked blood vessel that supplies blood to the brain, and hemorrhagic, which is bleeding into or around the brain. The most common type of stroke is ischemic, which refers to the loss of oxygen and nutrients for brain cells that occurs because the blood supply to a portion of the brain has been cut off. Ischemic strokes account for approximately 80% of all strokes, and can be further broken down into two subtypes: thrombotic, also called cerebral thrombosis, and embolic, also termed cerebral embolism. Thrombotic strokes are by far the more prevalent of ischemic strokes, and can be seen in nearly all aging populations worldwide. As people grow older, atherosclerosis, or hardening of the arteries, occurs. This results in a buildup of a waxy, cholesterol-laden substance in the arteries, which eventually narrows the interior space, or lumen, of the artery. This arterial narrowing occurs in all parts of the body, including the brain. As the process continues, the occlusion, or shutting off, of the artery eventually becomes complete so that no blood supply can pass through. Usually the occurrence of the symptoms of a thrombotic stroke are much more gradual and less dramatic than other strokes due to the slow, ongoing process that produces it. Transient ischemic attacks (TIAs) are one form of thrombotic stroke, and usually the least serious. TIAs represent the occlusion of a very small artery, or...
Please join StudyMode to read the full document