Impaired Cerebral Blood Flow Disorders Essays

     The most common causes of strokes are thrombosis. This is when a clot forms in one of the arteries, mostly in the carotid in the neck and the vertebral artery. The blood is thick and moves very slowly through the artery. The thrombus will form on the damaged area of the artery wall and will cut off the flow of blood to the brain. The area of the artery that is damaged is cause by arteriosclerosis. This form of

There are two major branches of strokes: those caused by narrowing or blockage of the arteries leading towards the brain, and those caused by blood vessel leaking or rupturing in the brain. Ischemic strokes account for approximately 87% of Stroke cases, which reduces the blood flow to the brain. About half of the Ischemic strokes are caused by clotting in small or large arteries, a smaller portion are caused by

Blood vessel length, when increased causes more friction or resistance thus making it more difficult for blood to flow through the vessel. In summation, increasing blood vessel length inversely effects flow rate but decreasing flow rate. My prediction was that an increase in blood vessel length would inversely effect blood flow. As evidenced in this experiment, with the increase of the blood vessel length, there was a decrease in blood flow.

The posterior cerebral arteries arise at this confluence, as do two small bridging arteries, the anterior and posterior communicating arteries. Cojoining the two major sources of cerebral vascular supply via the circle of Willis presumably improves the chances of any region of the brain continuing to receive blood if one of

* Cerebrovascular Disease: More commonly known as stroke cerebrovascular disease can be cause by either a colt or blockage that cuts off blood flow to a part of the brain or by haemorrhage. In both cases there is damage or death of the brain tissue that can cause paralysis, speech disorder, swallowing problems and immobility. People with diabetes and high blood pressure are at higher risk of stroke.

A stroke is a type of cardiovascular disease that affects the cerebral arteries, those blood vessels that carry blood to the brain. A stroke occurs when one of those blood vessels in the brain is obstructed or ruptures flooding the brain with blood. Depriving blood and oxygen to the brain results in those immediate cells death, causing the brain not to function properly. Once parts of the brain stop functioning, it can directly affect the areas of the body controlled (1).

When an artery in the brain is block (ie; TIA) open collateral vessels can allow blood to

According to our American Red Cross Nursing Assistant text a cerebral vascular accident, C.V.A., or stroke occurs when blood flow to a part of the brain is interrupted. The loss of blood supply results in the death of brain cells. (Page 91) When your brain starts to die the bodily functions the brain controls can be affected. The affected bodily functions depend on what part of the brain does not receive oxygen. Web MD says damage “can occur within 3-4 minutes if not treated.”

As mentioned above, strokes are pathophysiological changes. Ischemia which accounts for 87% of all strokes is a decrease or absent circulating blood which deprives neurons of necessary substrates. As there is no storage of glucose in the brain it leaves no opportunity for the chief ingredient for energy substrate and is incapable of anaerobic metabolism (Shah, MD, n.d.). Ischemia is a medical condition diagnosed when tissues do not have a sufficient oxygen supply, therefor resulting in a decrease in ATP energy, leading to necrosis of tissue. Decreased oxygen supply to tissue (ischemia) is caused by a blockage in an artery mainly from an embolism. An embolism is the breakage of an atherosclerosis formed in any coronary arteries. This floats freely in the blood stream, which eventually may plug a major artery in the brain (stroke), heart (MI) or lungs (lung failure). A thrombus occurs when an already

Cerebrovascular accidents, or strokes, will lead to brain damage that affects the functioning of executive function, memory, language, visuospatial performance and emotional states. Corresponding vertebral arteries and carotid arteries provide blood to the brain from the heart that the carotid arteries are internal and external sections of the thyroid cartilage. Where the optic nerve rests the internal artery distributes into the anterior and middle cerebral arteries. The vertebral arteries arise through the spinal vertebrae and meet the lower pons to form the basilar artery. The brain receives 15% to 20% of the oxygenated blood from the heart and can only endure fleeting interruptions of blood flow before neural operations

Correspondingly, there are two pathways that transports blood to the brain called internal carotid artery and vertebral artery. The internal carotid artery has three layers call the tunica adventitia, tunica media, and tunica intima. Tunica intima is made up of smooth muscle cells and elastin. The basilar artery forms and it branches out to the posterior cerebral arteries. The posterior cerebral arteries form the internal carotid arteries and when they connect they make cerebral arterial circle ( circle of willis). The middle cerebral arteries branch out two separate arteries called the anterior cerebral arteries. Each of these arteries are the force that direct the blood flow to the brain. There are three tiny vascular systems that work together to profuse the deep brain. Which are the pial, subependymal, and lenticulostriate arteries. The small area of white matter that depends on blood flow is called the subcortical “shed water” area. The subcortical is more prone than other areas of the brain to have ischemia. The leading cause of ischemia is the fibrin builds up and this cause a narrowing of the lumen. Which does not allow the flow of red blood cells and deprives the white matter of tissue of oxygen. The tissue then losses density and produces white matter lesions. The neurons become demyelinated which leads to loss of cognitive ability.

Stroke also known as cerebrovascular accident (CVA), cerebrovascular insult (CVI), or a brain attack. A brain attack is the loss of brain function by the cause of disturbance in the blood supply to the brain. This disturbance occurs due to either one of two causes which are ischemia (lack of blood flow) or a hemorrhage (high increase of blood flow directly into brain; parenchyma or into the subarachnoid space which surrounds the brain with tissue). Ischemia is a formation by a blood clot that is inside of a blood vessel located in the circulatory system called thrombosis or arterial embolism; which is a rapid interruption in the supply of blood flow to an organ or body part due to a clogged artery blocking the blood flow. Thrombosis is a

A stroke is a condition which is characterised as loss of brain functioning due to an interruption in the blood flow to the brain (Buzzard, 2013, pg. 5). There are two types of strokes, ischaemic and hemorrhagic strokes (Buzzard, 2013, pg. 6). Ischaemic strokes are the most common type of stroke (Gomes & Wachsman, 2013). This type of stroke occurs due to an insufficient flow of blood to the brain, which is usually caused by an artery blockage (Gomes & Wachsman, 2013). Hemorrhagic strokes are due to hypertension and may be caused by medical problems or blood vessel abnormalities (Gomes & Wachsman, 2013). The strokes severity and location of the brain that is affected determines the impact of the stroke in an individual (Gomes & Wachsman, 2013).(Gomes, 2013)

oxygen. The brain can be deprived oxygen either by a blockage such as a blood clot, or the

(c) Estimate the EC50 values for the effects of acetylcholine and nitroprusside in both types of arterial ring, and present these in a table.