Your brain needs a lot of oxygen and nutrients being carried by your blood, and your blood reaches it through a network of blood vessels which serve as its passageways. When one of these passageways is blocked, thereby preventing the arrival of blood in a certain area of yourbrain, stroke takes place. Deprivation of blood is not the only cause of stroke. When a particular blood vessel in your brain ruptures, and the blood goes into its substance, this is also called stroke.
Types of stroke
Due to cerebral thrombosis
Your blood vessels in the brain are not spared from the deposits of cholesterol and other forms of fats. If you are prone to having these deposits, all your blood vessels will have the same tendency to have them. Hence, when the opening of your blood vessel in the brain is narrowed by these deposits which have been accumulating for years, these blood vessels are prone to be blocked by blood clots which have been traveling in your bloodstream. Since the opening of the blood vessel is narrowed, it could easily be plugged by a clot which had been admixed with your blood. With the blockage, blood could not pass through, and a certain area of your brain is suddenly deprived of blood, resulting in stroke, which is now considered as due to a cerebral thrombosis. Had it not been for the narrowed blood vessel, stroke could not have happened.
Due to cerebral embolism
While your brain is left undisturbed for so many years, in other parts of your body, blood clots may have been formed. Some of these are attached to the inner structures of your heart.When your heart is behaving properly, they remain where they are, without producing any trouble at all. However, when it suddenly misbehaves, its rhythm is greatly disturbed that it is now out of sync. Consequently, its pumping becomes erratic and produces vibration that it is now medically described as fibrillating. When this takes place, blood clots from its inner chambers are thrown out in the blood which goes into circulation. When these blood clots reach the brain, they could block a blood vessel, resulting in stroke which is due to a cerebral embolism.
Figure2.Diagrammatic representation of a blood vessel in the brain which was never deposited with cholesterol and fats (A) but then a blood clot arrives plugging its opening (B). The diameter of the opening decreases as its location moves away from the heart—hence, very much prone to plugging.
Due to ruptured blood vessel
The wall of the blood vessels in your brain is very thin. This structural design is meant to allow easier transfer of oxygen from the blood to yourbrain and the transfer of carbon dioxide from yourbrain to the blood. In short, it is meant to allow easier exchange of gases. With this design, however, it cannot withstand high blood pressure. Thus, it is necessary that you always maintain your blood pressure at normal level because if you do not, a blood vessel in your brain could rupture, and you will suffer from stroke.
Figure 3. Diagrammatic representation of a normal blood vessel in the brain (A) and the ruptured blood vessel in (B) where the blood goes out through the leakage.
(To be continued)