Discuss the events of one cardiac cycle (electrical and mechenical Essay

Discuss the events of one cardiac cycle (electrical and mechenical events) - Essay Example Cardiac muscles are myogenic, which means that their contractions are started by the muscle itself, the action beginning from the sino-atriol node. The first stage of the cardiac cycle is known as the ventricular filling, which involves the flow of blood from the atria to the ventricles. The other stages include the movement of blood from the right ventricle through the pulmonary artery and the left ventricle through the aorta (Guyton and Hall, 2006). The contraction of the heart muscles on the left and right atria, which contract at the same time, is known as the atria systole (Klabunde, 2012). The events begin with the electrical current, which stimulates the myocardium contracts the heart chambers. This is then followed by the mechanical events. The electrical currents of the heart begin at the Sino atria node where action potential is generated (Williams, 2001). In the Sino-atria node, there is a rich supply of cells, capillaries and nervous supply, and the electrical current travels across the right and left atria. The atria are separated from the ventricles by a non-conducting band of connective tissues. Between the cardiac muscles are disc called gap junctions that provide electrical resistance at a low rate. The stimulation of each muscle fiber causes an electrical current to pass over the whole heart hence no external stimulus is required. The wave reaches the atrio-ventricular nodes in the lower right atrium, where it delays for a short period of time before conduction to the ventricles through the bundles up the purkinje fibers (Klabunde, 2004). Delaying at the atrio-ventricular node allows enough time for blood in the atria to get into the right ventricles. The atrio-ventricular node may act as a pace maker, which makes the action potential slow and unstable, depolarization occurs constantly due to the fall of calcium and potassium ions and this effect on the resting potential affects the heart rate. The mechanical

The Debate on the Compromise of 1850 Essay Example | Topics and Well Written Essays - 750 words

The Debate on the Compromise of 1850 - Essay Example Championed by Henry Clay it set off fiery and intense debates. Daniel Webster, of Massachusetts, and the Senator from South Carolina, John C. Calhoun, entered into a debate on the Senate floor during March of 1850. Though each man was against slavery on moral grounds, they were on opposite sides of the debate. At the heart of the debate, the saving of the Union, they were in agreement. Yet, the methods they advocated to reach that end were in opposition. Protecting the Union from dissolving was the central issue and the reason for the compromise. Both men met in favor on this and both men could see the looming threat of secession of the Southern States. Webster sees the impending violence and warns against flirting with the possibility when he states, "There can be no such thing as a peaceable secession. Peaceable secession is an utter impossibility". Calhoun, while in agreement, took a more pragmatic approach and said, "It is only through a long process, and successively, that the cords can be snapped until the whole fabric falls asunder." Calhoun, from the South, was guarding against further agitation of the North and also guarding against alienating his Southern constituency. Calhoun's speech is highlighted by what he sees as the unfair treatment of the South by the North. With slavery prohibited in the unorganized territories and the provisions of popular sovereignty, he decries the dwindling political representation that the South has in Washington. He further puts forth the notion that the South generates a preponderance of the revenue that goes into the pockets of Northern industrialists. His speech is centered around the theme that the South must be satisfied in order to remain a useful section of the Union, and it was the responsibility of the North to rectify past wrongs and promote a more equitable system. Webster, on the other hand, does not recognize the imbalance in justice between the North and the South. Webster believes that the tensions arise from the North's unwillingness to accept the slavery in the South. He dismisses Calhoun's insistence that the South is being mistreated by saying, "These are disputed topics, and I have no inclination to enter into them". Webster saw slavery, and the South's ownership of the issue, as the central issue. But beyond the simple notion of slavery, both men agreed that the tensions were being promoted by abolitionists geared toward arousing anti-slavery feelings in the south. Webster was politically bound to show some public support for the Whig slave owners that he was courting for national support, while Calhoun needed anti-abolitionist support at home. Though the main issue of the Compromise of 1850 was the problem of the Texas territory and it's claim on New Mexico, neither man chose to highlight it in their speech. Another critical issue, the Fugitive Slave Act, was detailed by Webster but Calhoun chose to ignore the issue. Webster blamed the North for a lack of will in enforcing the laws that they were sworn to uphold. Webster's notion was to give the South their slavery, enforce their traditions, and they would go away quietly and exist in harmony with the North. Calhoun saw the turning point from a different perspective and believed that no compromise was possible as long as the North did not politically recognize the contributions of the