The Circulatory System - Essay Example

your first & 20 February The Circulatory System Introduction One of the most significant differences between an object and a human is the ability of man to live. The notion of being alive is alien to a book, chair or house. There are a number of processes at work inside man that render him a living being. There are different systems in place for activities like eating, getting sick, having a child, doing exercises or the basic act of taking in air. One of these systems is the circulatory system. Because of what it does for man, the circulatory system can also be considered the most important one. Without the circulatory system, man will not be able to live. People usually associate the circulatory system with blood and they are not mistaken. In the most basic sense, the job of the circulatory system is to ensure that blood moves around inside man’s body, supplying the nutrients needed in order for all the parts of the body to function properly. While the blood carries the oxygen and nutrients to the body, it also collects the carbon dioxide from the same. If there is no proper flow of blood, the organs in the body will not be able to function well. The circulatory system can be divided into three parts: pulmonary circulation, coronary circulation and systemic circulation. The heart, lungs and bloods vessels are the major organs in each of these parts. Each individual part has its own unique process of blood circulation. “The successful circulation of each part results to an efficient distribution of blood throughout the body.” (Body) The heart The central organ in the circulatory process is the heart. Composed of four chambers that are divided by a wall, this muscle pushes 2,000 gallons of blood containing oxygen and nutrients into the body. (Dowshen) The heart sends the blood out through its pumping motion. “It beats about 100,000 times a day, more than 30 million times per year, and about 2.5 billion times in a 70-year lifetime (Dowshen).” The speed of the heart’s pumps depends on the kind of activity the body does. It pumps slower when the body is at rest and faster when the body is in motion. This is because man uses up more energy when immersed in activity. Energy comes from oxygen and oxygen comes from blood. The source of oxygen-rich blood is the heart. The four chambers of the heart can be grouped into two; namely, the upper and lower. The upper chamber or left and right atria receive the blood which has passed through the different organs in the body. On the other hand, the heart releases the blood to be used from the lower chamber or left and right ventricles. Two cardiac valves separate the bottom part of the heart from the blood vessels that allow blood to the rest of the body. The pulmonic valve is between the right ventricle and the pulmonary artery which goes to the lungs. The aortic valve is between the left ventricle and the aorta. The heart also has two major arteries which in turn gives blood to the heart. The right coronary artery allows blood into the right atrium, right ventricle and the bottom part of the right and left ventricle. In contrast, the left coronary artery pumps blood to the left atrium and the left ventricle. Because of the heart’s function in supplying blood, it can be said that the heart is the most important organ in the circulatory system. The blood vessels Blood moves around the body through three groups of blood vessels. Aside from those which deliver and release blood to and from the heart, there are also blood vessels responsible for distributing blood throughout the body and bringing blood back to the heart. The first group of blood vessels can be found in the heart. When leaving the heart, blood flows through two arteries. The aorta is the thickest blood vessel and carries blood with oxygen to the rest of the body. The pulmonary artery, on the other hand, delivers blood to the lungs which converts oxygen-poor blood into oxygen-rich blood for the body to use. The second group of blood vessels brings the “used” blood back to the heart. These are called veins. The veins are special because they do not let the blood flow backwards. The last group is the capillaries. These tiny capillaries are responsible for delivering blood with nutrients and oxygen to the rest of the body. The capillaries also clean the body by getting the carbon dioxide. After the blood goes through the body, the capillaries return the blood to the veins and the veins transport the blood back to the heart. The blood vessels are as important as the heart because these are the immediate sources of blood for the different organs. The amount of blood the heart can pump would only be a waste without the blood vessels because blood would not be able to reach its intended recipients. The lungs The circulatory process in the lungs is the third and can be considered final part of the circulatory system. This organ is as important as the heart and the blood vessels because it is responsible for making oxygen available for the body to use. The lungs have lobes or divisions, three on the right and two on the left. The lungs contain bronchioles or small tubes which bring air to small air sacs called alveoli which are in turn connected to capillaries. (Bailey) Through the nose and mouth, the lungs take in oxygen-filled air. The oxygen is stored in the alveoli. When the oxygen-poor blood is brought by the capillaries to the alveoli, the stored oxygen attaches to the hemoglobin in the red blood cells. The oxygen-rich blood is now transported back to the heart and pumped back into the body. The cells in the body get the oxygen and release carbon dioxide into the blood. This goes back to the heart, then to the lungs. The carbon dioxide is released in the alveoli then outside the body when man exhales. (Durani) Health Risks The circulatory system is crucial to the well-being of man. Since the whole process is made up of three different independent systems, it is vital that the various organs in these independent systems work efficiently. Otherwise, the man will experience health issues. In a worst case scenario, since the three independent systems functioning together complete the circulatory system, should one of these three parts not work well, the two other systems will likely be affected and ultimately, the entire circulatory system may fail. Without the circulatory system, man cannot exist. Heart attacks, hypertension and coronary artery diseases are just a few of the problems affecting the success of coronary circulation. These conditions alter the blood flowing through the heart and thus put a strain on the heart. Since the heart is responsible for supplying blood to the body, it would need to pump harder than usual to deliver the right amount of blood. Insufficient blood supply can lead to the deterioration of organs and cells. Asthma, bronchitis and pneumonia are some of the reasons it would be difficult for the lungs to take in oxygen-filled air. Since oxygen is important for all of the body organs, it is significant that the lungs make enough oxygen available for the blood in the capillaries to acquire. Although it is really the blood they carry which is significant to the body processes, problems with the blood vessels should also be of utmost concern because they should always be able to facilitate the transport of blood. “The blood vessels play a major role in controlling the rate of flow of blood […], and they possess the entire responsibility for the distribution of the blood and its flow pathways (Peterson).” Valves in the veins must work properly so there is no backflow of the blood. Capillaries must be able to facilitate the exchange of carbon dioxide and oxygen. Blockage of any of the blood vessels is detrimental and can have fatal results. The system in animals Although animals are similar to men in the sense that they are also considered living beings and as such have almost the same body processes, their circulatory system is quite different from humans. In general, the circulatory system is made up of a heart, blood and blood vessels. Since animals may be big or small, their circulatory systems depend on their size. Small animals do not have a circulatory system because their inner parts are near their covering. As such, the oxygen they need goes through their covering and directly to the inner cells. The same cannot be said with larger animals because they are like humans. Their inner parts are far from their skin. Animals with circulatory systems either have an open or a closed system. The difference in the two systems has to do with the delivery of blood. In an open system, after the heart pumps the blood into the blood vessels, the blood vessels literally deposit the blood into spaces within the organs. (Gregory) An example of these animals would be insects. Closed circulatory system for animals would be similar to that of humans. Valves in the blood vessels prevent backflow and transfer oxygen through the walls of the blood vessels. The heart also contains atria and ventricles which contract to push blood out. The atria receive the blood and push it out to the ventricle which pushes the blood out to the body, lungs or gills (Gergory). The blood flow is only from atria to ventricles. In fish, the blood gets the oxygen from the gills. In amphibians, the atria are divided into a left part which receives blood from the lungs and a right part which receives blood from the body. Once in the ventricle, some oxygen-rich and oxygen-poor blood mix. In reptiles, the atria are similar to that in amphibians but the ventricle is partially divided in order to reduce the chances of oxygenated and unoxygenated blood mixing. (Gregory) Still in other animals, the heart is composed of four chambers like in humans. Conclusion Indeed, the circulatory system plays a major role in the ability of human beings and animals to live. Without the processes involved in the circulatory system, these living creatures would not be able to receive the oxygen and nutrients their bodies need to function efficiently and promote life. References: Bailey, Regina. “The Lungs.” About.com Biology. About.com, n.d. Web. 23 February 2013. “Body Systems.” The Human Health. The Franklin Institute, 1996. Web. 19 February 2013. Dowshen, Steven. “Heart and Circulatory System.” KidsHealth. The Nemours Foundation, 2010 May. Web. 19 February 2013. Durani, Yamini. “Lungs and Respiratory System.” TeenHealth. The Nemours Foundation, 2012 October. Web. 23 February 2013. Gregory, Michael. “Circulatory System.” Welcome to the Biology Web. Clinton Community College, n.d. Web. 23 February 2012. Peterson, Lysle. “Regulation of Blood Vessels.” Circulation: Journal of the American Heart Association, XXI (1960): 749-759. Print. Read More