Lab Report - Blood Flow and Vascular Function Article

Lab Report - Blood Flow and Vascular Function - Article Example It is the sympathetic nervous system which sends out signals to arteries instructing the smooth muscle, arterial wall to contract and relax. Veins are the other type of major blood vessel and are responsible for carrying blood towards and into the heart, in order to become oxygenated. Veins operate under lower pressure than arteries and do not possess the same elasticity that arteries do. Veins transport unoxygenated blood as opposed to arteries which carry oxygenated blood. Veins, like arteries, have lumens, but they are comparably wider than the lumens of arteries. Veins are composed of venules, which are tiny blood vessels that pull blood from capillaries into the actual vein. Veins are actually composed of three tissue layers but are less elastic than the walls of arteries. The regulation of blood flow during exercise is governed by the demands of the muscle tissue being used. Certainly, when an individual is exercising, the heart rate increasing as a response to the body’s immediate need for larger amounts of oxygenated blood. The body’s blood flow rate can increase during exercise by as much as 20 times more than what it is at rest. During periods of exercise, all of the body’s capillaries are opened and in use versus the mere  ¼ of the body’s capillaries which are used at rest. During periods of exercise, the body experiences what is called low oxygen tension. This is a result of the use of multiple muscular groups during periods of heavy activity. In addition, vasodilators are released as the demand for oxygenated blood throughout the body increases, â€Å"Low oxygen tensions resulting from greatly increased muscular activity or the release of vasodilator substances such as lactic acid, carbon dioxide, and potassium ions causes dilation of precapillary sphincters. Increased sympathetic stimulation and epinephrine released from the adrenal medulla cause some vasoconstriction in the

The war between US an Iraq 2003 Research Paper Example | Topics and Well Written Essays - 2750 words

The war between US an Iraq 2003 - Research Paper Example Other reports have also revealed that as a result of the war, debt reliefs have been offered to the country and the country has been released from the control of their dictator Saddam Hussein. This paper shall be a quantitative research paper with respondents from the Iraqi nation chosen randomly across various territories in the region. Major potential research findings for this paper include the fact that the Iraqi War has brought about economic hardships for the people, decreasing their employment rates, and worsening their poverty status. The war has also caused much political chaos through political infighting and major corrupt activities by government officials. Finally, it has also brought about difficulties in the delivery of health, educational, and social services to the people. On March 20, 2003, the world was witness to the second gulf war with the invasion of American troops in Iraq. War was launched against Iraq because of the latter’s alleged possession of Weapons of Mass Destruction (WMDs) which were in apparent violation of its terms of surrender in the wake of its Kuwaiti invasion in the early 1990s. Although inspections by the UN on Iraqi weapons depots and military institutions yielded no WMDs, US intelligence reports insisted that Iraq was in possession of such weapons. After a series of failed negotiations and after Iraq refused UN inspections in the early months leading up to the March invasion, the US troops were deployed into Iraq. In the days following the attack, the hunt for Iraqi dictator Saddam Hussein was also launched and in December, 2003, he was finally apprehended and charged with the execution of 148 Shi-ites in 1982. He was executed in December 2006 by hanging. In the meantime, US troops continued to occupy Iraq with the so le purpose of assisting the interim government in the management of insurgent activities in the country. A semblance of a US-initiated transition