Brain Stroke

What is brain?
Brain is brain, everybody knows what is brain, brain is the master control center of the body. The brain constantly receives information from the senses about conditions both inside the body and outside the body. The brain rapidly analyzes this information and then sends out messages that control body functions and actions. The brain also stores information from past experience, which makes learning and remembering possible. It is the source of thoughts, moods and emotions.
Your brain has 100 billions nerve cells and trillions of nerve conections. Although it's only two percent of your body's weight, it uses 70 percent of your body's oxygen and other nutrients. Because your brain can't store these nutrients as muscles can, it requires a constant flow of blood to keep working properly. A stroke occurs when this blood supply is altered and brain tissue is starved of blood. Within four minutes of being deprived of essential nutrients, brain cells begin to die.
There are two main types of brain stroke.
1. Ischemic. A about 80 percent of stokes are caused by atherosclerosis ( buildup of cholesterol-containing fatty deposits called plaque). Growth of plaque roughens the inside of your artery. The irregular surface can cause turbulent blood flow around the buildup-like a boulder in a rushing stream- and trigger development of a clot. More than half of ischemic strokes are caused by stationary ( thrombotic ) blood clots that develop in the arteries leading from your heart to your brain. A less frequent form of ischemic stroke occurs when a tiny piece of clotted blood breaks loose from the artery wall and is swept through larger arteries into small vessels inyour brain. A clot that may have developed in a chamber in your heart can also break loose. If the moving (embolic) clot lodges in a small artery and blocks blood flow to a portion of your brain, a stroke occurs. An ischemic stroke usually affects the cerebrum, the portion of your brain that controls your movement, languages, and senses.
2. Hemorrhagic. This type of stroke occurs when a blood vessel in your brain leaks or ruptures. Blood from the hemorrhage spills into the surrounding brain tissue, causing damage. Brain cells beyond the leak or rupture are deprived of blood and are also damaged. One cause of hemorrhagic is an aneurysm. This "ballooning" from a weak spot in a blood vessel wall develops with advancing age. Some aneurysm may also form as a result of a genetic predisposition. As an aneurysm forms, the vessel wall becomes thin and stretched. An aneurysm that grows to at least three-eights of an inch in diameter (about the size of the head of a thumbtack) is most likely to rupture.
Most common cause of a hemorrhagic stroke is high blood pressure(hypertension). The constant force exerted by uncontrolled high blood pressure can weaken blood vessel walls. Hypertension increases your risk of a hemorrhagic stroke whether or not you have an aneurysm. An uncommon cause of hemorrhage is rupture of an arteriovenous malformation. This congenitally malformed nerwork of thin-walled blood vessels can burst and allow blood to leak into your brain, damaging or destroying tissue.