Structure And Function Of The Heart Physical Education Essay

Structure And Function Of The Heart Physical Education Essay The cardiovascular system is a very complex and unique system. The main structures of the cardiovascular system include the heart, blood, and blood vessels arteries, capillaries and veins. It is a system that allows all nutrients such as amino acids, electrolytes and lymph, gases, hormones, and blood cells to pass throughout the body, these all aid in the process of fighting diseases, stabilizing body temperature and maintaining homeostasis. Coronary, pulmonary and systemic circulations are the systems that allow blood to be pumped throughout the body, coronary circulation is the system that allows blood to be pumped through the heart, pulmonary circulation is the system that pumps blood through to the lungs and the systemic circulation which is the system that pumps the blood around the rest of the body and to the remaining organs. As humans we have a closed cardiovascular system which means the blood never leaves the circulation of the blood vessels. The coronary circulation is part of the systemic circulation by definition it supplies blood to muscles- muscles of the heart (myocardium), however it is the only system to provide the heart with blood. The blood comes from the aorta and filters through into the right atrium. If the heart didnt receive the blood supply, it would cause severe tissue damage. The pulmonary circulation uses the pulmonary artery to take de-oxygenated blood away from the heart through to the lungs which is where the blood is then oxygenated. The de-oxygenated blood enters the right atrium of the heart and flows through the tricuspid valve and then from there it flows into the right ventricle, here it is then pumped through the pulmonary semilunar valve into the pulmonary artery to the lungs. In the lungs is where the gas exchange takes place, where the CO2 is released and the blood then absorbs oxygen. This is the stage when the pulmonary vein returns the freshly oxygenated blood to the heart. The systemic circulation on the other hand takes the oxygenated blood from the heart and transports it throughout the rest of the body except from the lungs. The system then provides all other organs with the oxygenated blood, the circulation then returns all of the de-oxygenated blood back to the heart for the process to start all over again. The systemic circulation is a much lengthier system than the pulmonary circulation due to transporting blood all over the body. (1)The heart pumps oxygenated blood to the body and deoxygenated blood to the lungs. In the human heart there is one atrium and one ventricle for each circulation, and with both a systemic and a pulmonary circulation there are four chambers in total: left atrium, left ventricle, right atrium and right ventricle. The right atrium is the upper chamber of the right side of the heart. The blood that is returned to the right atrium is deoxygenated (poor in oxygen) and passed into the right ventricle to be pumped through the pulmonary artery to the lungs for re-oxygenation and removal of carbon dioxide. The left atrium receives newly oxygenated blood from the lungs as well as the pulmonary vein which is passed into the strong left ventricle to be pumped through the aorta to the different organs of the body. The blood circuit is flows in the shape of a figure of 8. There are two loops to this circuit. The top loop carries the blood from the heart to the lungs and back (the pulmonary circulation). The bottom loop carries the blood from the heart all over the body (systemic circulation). The 4 main stages of the cardiac cycle are: Atrial Diastole -which is where the top chamber (atria) relaxes and fills with blood from the veins Atrial Systole- where the atria contracts and blood is forced into the relaxing bottom chambers which are otherwise known as ventricles Ventricular systole- which is where the ventricles contract and blood is forced out of the heart in to the arteries. Ventricular diastole -when the ventricles relax and become ready for the next pump cycle. The circulatory system also consists of the lymphatic system; this is a non-closed system that carries a clear liquid called lymph towards the heart and allows an average of 20 litres of blood per day through capillary filtration which removes plasma while leaving the erythrocytes. Around 17 litres of filtered plasma get reabsorbed into the blood vessels; however 3 litres are then left behind in the interstitial fluid. The main role of the lymph system is to provide an auxiliary route for the extra 3 litres to return to the blood. (4) The lymphatic system has multiple interrelated functions: it is responsible for the removal of interstitial fluid from tissues it absorbs and transports fatty acids and fats as chyle from the digestive system it transports white blood cells to and from the lymph nodes into the bones The lymph transports antigen-presenting cells (APCs), such as dendritic cells, to the lymph nodes where an immune response is stimulated. There are three main blood vessels in the cardiovascular system, these are the arteries, veins and capillaries; arteries are responsible for carrying the blood away from the heart, they are made up of a thick elastic muscular wall, which is capable of stretching as blood is being pumped through at a high pressure. The muscle walls are able to contract to force the blood along through the arteries. Veins are made up of a much thinner, less muscular wall compared to the arteries. The blood in the veins is under considerably much lower pressure compared to the blood in the arteries, this is because arteries need higher pressure in order to deliver the oxygenated blood to the arterioles, capillaries, other organs and tissues and to also prevent the back flow of blood, veins dont require this high pressure because the de-oxygenated blood can travel from the tissues to the heart through the veins with the help of the muscle contractions. One of the functions of the veins is to ensure that the blood doesnt flow back towards the heart, veins contain valves every few centimetres along, this helps them push the blood in one direction. However muscle contraction and relaxation can also occur to help squeeze the walls of the veins to help the blood flow back towards the heart when necessary. You can use a stethoscope to hear pulmonary circulation. The sounds that are audible are the ventr icles contracting and the valves closing. Capillaries are the smallest of all the blood vessels they have a wall that is one cell thick, capillaries connect the arterioles and venules this is where all the exchange of nutrients and gases such as oxygen and carbon dioxide occurs- through the capillary surfaces. Leucocytes are able to leave our capillaries in order to digest any micro-organisms that could be a potential threat or disease. Arteries, veins and capillaries are all blood vessels of the body and all of them are routes for the blood to pass through to provide their functions. They all contain tunica externa, tunica media and tunica intima. Blood is carried away from the heart via the arteries and the blood returns to the heart through the veins. Our circulatory system is a transport system the carries our blood, oxygen and waste products to and from our bodys cells in order for our bodies to functions. (2) During systemic circulation, blood passes through the kidneys. This phase of systemic circulation is known as renal circulation. During this phase, the kidneys filter much of the waste from the blood. Blood also passes through the small intestine during systemic circulation. This phase is known as portal circulation. During this phase, the blood from the small intestine collects in the portal vein which passes through the liver. The liver filters sugars from the blood, storing them for later When it comes to heat regulation in order to keep cool our capillaries are capable of forcing the blood supply to the surface of the skin, this allows the air to reach the blood and to cool it more easily, and sweating is also induced as part of the heart regulation. However when trying to keep warm our capillaries work hard in order to reduce the blood at the skin surface and sweating is also reduced. This is known as vasoconstriction and vasodilation. Heat regulation is one of the key functions of the circulatory system as well as many other functions. Signals along nerves from the hypothalamus control both vasodilation and vasoconstriction. It is necessary for the human body to have vasodilation and vasoconstriction as it regulates the bodys blood pressure, by constricting and releasing the vessels to allow more or less blood through, for example whilst exercising our heart and breathing rates increase and blood vessels in our limbs dilate in order to deliver more oxygenated blood to our working muscle cells. (3) Vasoconstriction is the narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels, particularly the large arteries and small arterioles. The process is the opposite of vasodilation, the widening of blood vessels. The process is particularly important in staunching haemorrhage and acute blood loss. When blood vessels constrict, the flow of blood is restricted or decreased, thus, retaining body heat or increasing vascular resistance Our blood that is carried around in our cardiovascular system is responsible for maintaining its levels in many advance ways. For example haemostasis is a complex chain reaction that produces the blood to clot this is otherwise known as coagulation. The body clots in two different ways, there is the normal clot which is a good formation that stops bleeding, and there is also a thrombus which is bad as it can block the blood vessels. The endothelium is the cells that create the vessel wall. When the endothelium becomes damaged, for example, when a cut breaks through the wall, collagen fibres then start to appear. These collagen fibres are a protein that is vital for the structure of the vessel wall, these fibres then allow platelets to attach themselves, these are produced from precursor megakaryocytes, its these platelets that lead to the formation of blood clots. The platelets become activated and begin to release a chemical called Thromboxane A2 which calls on more platelets to the area. Fibrin, which is the insoluble form of the soluble protein fibrinogen, is then converted by thrombin. The fibrin begins to appear and layers on top of the platelets which start to fuse them together. This fibrin helps the clot form as the red blood cells stick to the fibrin. This process then repeats until the clot is fully formed. This process is important for the cardiovascular system, this is because the average human contains around 4.7 to 5.7 litres of blood, if around 30%-40% of this is lost it could prove fatal or cause severe damage. The blood the is carried around the cardiovascular system, is made of erythrocytes, leucocytes, platelets and plasma which is mainly water, amino acids, proteins, carbohydrates, lipids, hormones, vitamins, electrolytes, dissolved gases, and cellular wastes. Erythrocytes contain a globular protein called haemoglobin which allows oxygen to bind to it; this allows the erythrocytes to transport oxygen throughout the body and organs. The haemoglobin molecule is made up of 4 polypeptide chains, 2 containing 141 amino acids and 2 containing 146, attached to each polypeptide chain is a molecule that contains iron and is known as a haem, the function of this molecule is to absorb oxygen until it is fully saturated. Carbon dioxide however binds to the amino acids and not the erythrocytes, this means that is binding to the proteins and not the haem.

Gothic Cathedral of Florence

This Gothic Cathedral of Florence is now becoming a great difficulty for me. If the Cathedral’s commission was given to me from the beginning of the construction, it would not have been such a pain. But this unfinished dome! Oh my God! Sometimes I get afraid if I am not able to complete it with perfection, I am not going to get even good food from the King. I sometimes wish I was not an architect I always wanted to become a musician. I could have listened to music all day long. I even though of starting up a musical school of mine but the desires of the King have led me to this place.I do not want to get insane. I will have to take some step. Decided! I am going to buy a sheep or a goat from Frodo. I know he will sell me one of his sheep or a goat. Then I am going to make a bagpipe out of the sheep skin. These bagpipes are not available in this city. Nothing is good about this city except the food. Then I will take this bagpipe to the King and tell him that I am a musician by birth and I have changed my occupation now. But will he kill me then? Diary you tell me, you tell me, will he kill me or spare me? I do not want to die.I am not becoming any musician. I am a good architect and will die an architect. Diary, I am now going to design the dome, a dome which has not been designed before. This will be the first dome of its type. August 30th, 1436 I am glad the dome is completed now. I do not believe that I have done it though it took very long. I am tired now I have to get some rest. I should go to some other city of Greece or Rome and leave Italy now for some time. I do not admire the dome so much as others do. I have not even gotten a chance to see it clearly myself.God seriously I have done some hard work on the dome and I am really proud of it. I hope the dome will remain as it is now for centuries. The material used in the structure has been the best available. If war does not struck Italy, this dome will remain enact for some centuries I believe. I wish my father was alive at this moment I would celebrate this moment with him and I am sure he would be really proud of his son who helped the King in building the largest dome ever built. The King has invited me at the dinner; God knows how many presents I am going to receive from all the friends of the King.Only this thing worries me that when will the dome be decorated with the tiles and stones that I have recommended. I hope the dome is completed in my lifetime though I do not wish to live too long in this world. And yes today I am going to thank all of the supporters who helped me in the making of the dome. Lorenzo has been very supportive as he also took over the construction when I was suffering from illness. I am getting late for the dinner now I have to wear the clothes and leave for the dinner the horse cart must have arrived.

Chris Mccandless s Into The Wild - 2337 Words

The world loves dreamers. Every, day people are inspired by other people who strive to achieve their dreams of grandeur. They pick their heroes: charismatic, daring, and habitually dead. The romantic ideals of these individuals present skewed views of reality and often lead to dire situations. Chris McCandless, subject of Jon Krakauer’s successful novel, Into the Wild, met his fate in the Alaskan wilderness. McCandless donated all his money to OXFAM America after double majoring in anthropology and history at Emory University, then walked away from his old life. He took on the name Alexander Supertramp, and the next time his family would see him would be as a corpse, brought to his knees by nature’s unforgiving presence. At the beginning of his travels, McCandless â€Å"tramped around the West†¦ spellbound by the scale and power of the landscape†¦Ã¢â‚¬  (Krakauer, â€Å"Death of an Innocent† 4). He was a romantic, admiring nature and seeking out the most remote of places to end his life of consumption. He faced many trials throughout his travels, but always seemed to come out on top. His father explained, in an interview with Krakauer, that â€Å"’He was good at almost everything he ever tried’ †¦ ‘which made him supremely overconfident’† (7), and this was his downfall. Hubris. McCandless’ dream of living his life away from society’s poison was romantic in itself. Romanticism’s trademarks are imagination and emotion. The acute appreciation of outside nature, an interest in the remote, theShow MoreRelatedChris Mccandless s Into The Wild3734 Words   |  15 PagesNovember 23, 2014 Into The Wild Themes Jon Krakauer’s Into The Wild chronicles the journeys and events leading up to the death of a young man named Chris McCandless. Chris was a vagabond who traded friends and family in exchange for adventure, but ultimately wound up dead in the Alaskan wilderness. 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Throughout the novel, Chris McCandless facesRead MoreAnalysis Of Chris Mccandless s The Wild And Understanding His Life 1196 Words   |  5 Pagestimes they are simply unimportant part of your life. When having a unique personality, like Chris McCandless, becoming friends is hard but many acquaintances can be made. After reading Into the Wild and understanding his life, many people can be thought of who would have benefited Chris if he got to know them. These people could help Chris see the other side of the story as well as change the tragic ending. Chris would benefit the company of Ted Kaczynski, Garret Mason, and Bill Gates. All three of theseRead MoreAnalysis Of Chris Mccandless s The Wild And Never Came Back Out 1128 Words   |  5 PagesMaryna Nguyen Ms. Mensen US Lit. A 24 November 2014 Chris McCandless: Who Went Into The Wild and Never Came Back Out To the average person, going off and living off the land is far fetched from the ideal â€Å"perfect life† or â€Å"American Dream†. To Christopher McCandless, it’s another story, he isn’t the type of person to â€Å"stick to the status quo†, he follows the things that he believes could benefit himself. To some people, it may be narcissistic because it’s selfish to only think about what is goodRead MoreJon Krakauer And Chris Mccandless1015 Words   |  5 PagesJon Krakauer and Chris McCandless Into the Wild, a novel talks a young boy called Chris McCandless who was born in a rich East Coast family and traveled to Alaska by hitchhiking until he walked into the wilderness and then he dead. He loved to adventure, seek a place without civilization and escape where he lived. The author of the novel, Jon Krakauer, has similar experience to McCandless. Jon Krakauer climbed Devils Thumb, the one of dangerous mountains in Alaska alone when he was twenty-three,Read MoreInto The Wild By Jon Krakauer Essay1237 Words   |  5 Pages Jon Krakauer s novel â€Å"Into the wild†, Is a story about a young man named Christopher McCandless or â€Å"Alex Supertramp† who went on a self discovering odyssey in which he had traveled around the U.S. The story surrounds Chris and his travels and what he had done at the time, leading to his death in August 1992. Thus the story takes a direction in the viewpoints of the people Alex has come across through in his travels. It speaks a bout what he had done at the time of his journey before he hadRead MoreChris McCandless is NOT a Hero1239 Words   |  5 PagesInto the Wild, written by John Krakauer tells of a young man named Chris McCandless who 1deserted his college degree and all his worldly possessions in favor of a primitive transient life in the wilderness. Krakauer first told the story of Chris in an article in Outside Magazine, but went on to write a thorough book, which encompasses his life in the hopes to explain what caused him to venture off alone into the wild. McCandless’ story soon became a national phenomenon, and had many people questioningRead MoreThe Journey Of Chris Mccandless1654 Words   |  7 PagesWhether McCandless was a vagabond, genius, whack job, free spirit, rebel, or poet, Christopher McCandless (also known by the pseudonym Alexander Supertramp) was unique among men. At an age when most upper-class kids begin their arduous climb toward becoming the next big thing, Christopher McCandless went in the opposite direction—he became a nobody. Through perusing Into The Wild, I have detested a ton of feelings for the most part outrage. I have never believed that such individual would remain

Example Java Code Password Dialog Box Program

Here is example Java code showing how to make a password dialog box. This program uses a combination of the JOptionPane class and the JPasswordField class. When this program is run a JOptionPane is shown containing a JPasswordField, a JTextField, an OK and Cancel button. The JFrame behind the JOptionPane uses a text area to provide feedback about the input the user has made and what buttons have been pressed. The article relating to this code is How to Make a Password Dialog Box. Also, have a look at JPasswordField Overview if you want more specific information about the JPasswordField class. Note:For this Java program to work it needs to be saved in a file called PasswordDialog.java //Imports are listed in full to show whats being used //could just import javax.swing.* and java.awt.* etc.. import javax.swing.JFrame; import javax.swing.JOptionPane; import javax.swing.JTextField; import javax.swing.JTextArea; import javax.swing.JPasswordField; import javax.swing.JPanel; import javax.swing.JLabel; import java.awt.GridLayout; import java.util.Arrays; import java.awt.EventQueue; public class PasswordDialog { //Note: Typically the main method will be in a //separate class. As this is a simple one class //example its all in the one class. public static void main(String[] args) { //Use the event dispatch thread for Swing components EventQueue.invokeLater(new Runnable() { Override public void run() { createGuiFrame(); } }); } //handles the creation of the JFrame and //all its components private static void createGuiFrame() { JFrame guiFrame new JFrame(); //make sure the program exits when the frame closes guiFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); guiFrame.setTitle(Dialog Box Example); guiFrame.setSize(500,300); //This will center the JFrame in the middle of the screen guiFrame.setLocationRelativeTo(null); guiFrame.setVisible(true); //Using a JTextArea to diplay feedback //(i.e., the username and password entered JTextArea tracker new JTextArea(Password Tracker:); guiFrame.add(tracker); //Using a JPanel as the message for the JOptionPane JPanel userPanel new JPanel(); userPanel.setLayout(new GridLayout(2,2)); JLabel usernameLbl new JLabel(Username:); JLabel passwordLbl new JLabel(Password:); JTextField username new JTextField(); JPasswordField passwordFld new JPasswordField(); userPanel.add(usernameLbl); userPanel.add(username); userPanel.add(passwordLbl); userPanel.add(passwordFld); //As the JOptionPane accepts an object as the message //it allows us to use any component we like - in this case //a JPanel containing the dialog components we want int input JOptionPane.showConfirmDialog(guiFrame, userPanel, Enter your password: ,JOptionPane.OK_CANCEL_OPTION, JOptionPane.PLAIN_MESSAGE); char[] correctPassword {a, P, a, S, s, W, o, R, d}; if (input 0) //OK Button 0 { tracker.append(\nUsername entered was: username.getText()); //Retrieve password char[] enteredPassword passwordFld.getPassword(); tracker.append(\nPassword entered was: String.valueOf(enteredPassword)); if (Arrays.equals(correctPassword, enteredPassword)) { tracker.append(\nThe password entered is correct!); } else { tracker.append(\nCall security - its an imposter!); } //Note: best practice is to zero out the array //that contains the password. (Bit silly here //as Im printing the password to show how its retrived //but keep it in mind when using JPasswordFields.) Arrays.fill(enteredPassword, 0); } else { //either the cancel button or the x //has been pressed tracker.append(\nDialog cancelled..); } } }