Final answer:
When blood flow to a part of the brain is cut off by a blockage, a stroke occurs, leading to tissue damage and potentially permanent cell death. The specific functions lost depend on the area of the brain affected. A blood clot is the common cause of such blockages, and the outcome can be severe, including impaired brain functions or even fatality.
Step-by-step explanation:
When blood flow to a part of the brain is obstructed, a condition known as a stroke, or cerebrovascular accident (CVA), occurs. The blockage is typically caused by an embolus—such as a blood clot, a fat embolus, or an air bubble—preventing the artery from delivering vital nutrients and oxygen to brain tissues. This can quickly lead to permanent damage or cell death within hours.
The brain's complex structure means that a stroke in one location can disrupt very specific functions depending on the region affected. For example, a stroke in the lateral medulla might impair the ability to swallow, while those affecting parts of the cortex can result in more abstract deficits, like the inability to recognize faces or the impairment of movement control.
Without prompt intervention, ischemia—reduced blood flow—and hypoxia—decreased supply of oxygen—can occur, leading to severe impairment of function or even cell death. A hemorrhagic stroke, on the other hand, involves bleeding into the brain due to a damaged blood vessel, which can cause similar devastating effects through physical pressure and edema in the brain.