Energy Metabolism free essay sample

The respiratory system consists of the nose, mouth, pharynx, larynx, trachea, bronchi and lungs. These provide a passageway to allow air in and out of the body. Every cell in the body requires oxygen to survive. The primary function of the respiratory system is the exchange of gases. The respiratory system allows oxygen and carbon dioxide exchange, this is necessary to sustain life. During the process of breathing air is inhaled and carbon dioxide is exhaled, this change of gases occurs in the alveoli.The inhaled oxygen passes into the alveoli and then diffuses into arterial blood. The waste rich blood from the veins releases carbon dioxide into the alveoli which is released through exhaling. Air enters through nostrils which contain coarse hairs. The pharynx is shared between the digestive and respiratory system and extends between the nostrils and the larynx. The larynx joins the pharynx to the trachea; it consists of cartilages and is also known as the voice box. The trachea divides to form the primary bronchi, the left and right bronchi which the bronchi are two tubes that carry air into the lungs and they . reak down into smaller branches which are called bronchioles. At the end of these are air sacs called alveoli which absorb oxygen from the air. Oxygen diffuses from the alveoli into the blood where it is transported to every cell in the body. 98. 5% of oxygen is carried in the blood by being bound to hemoglobin and 1. 5% is carried by dissolving in the plasma. The pressure of the oxygen in the alveoli must be kept higher than blood pressure to maintain a concentration gradient. Breathing insures there is continuous fresh air brought into the lungs and alveoli. Alveoli have very thin walls and are abundant which means they are efficient in exchanging gases. Mechanisms of Breathing Breathing occurs of the changes of pressure within the thorax.When we inhale the intercostal muscles and diaphragm contract and expand the chest cavity. The diaphragm flattens and moves down and the rib cage is moved upwards and out by the intercostal muscles this increase the size of the lungs and draws air in. When we exhale the diaphragm and intercostal muscles relax and return to their original position. This reduces the size of the thoracic cavity and forces air out of the lungs. The Digestive System The digestive system allows food to be broken down and made soluble so it can be absorbed by the body.Once the food is absorbed by the body it is changed into energy to fuel the body. The main function of the digestive system is to break down the food and fluid so that they are simple chemicals that can easily be absorbed into the bloodstream so they can be transported around the body. The mouth is where chewing occurs; this chewing breaks the food down into pieces which can be more easily digested. Saliva mixes with the food in the mouth to begin the process of breaking it down into a form which the body can absorb. The esophagus receives food from the mouth after swallowing and then delivers it to the stomach.The stomach holds food which it is being mixed with enzymes which continue the process of breaking down the food into a useable form. When the contents of the stomach are processed they are released into the small intestine. In the small intestine food is broken down by enzymes released from the pancreas and bile from the liver, the food is moved through and mixed with digestive secretions. The small intestine is made up of three segments the duodenum, jejunum and the ileum, the jejunum and the ileum are mainly responsible from the absorption of nutrients in to the bloodstream.These contents start out semi-solid and end in a liquid form after passing through the organ. Water, bile, enzymes and mucous change its consistency, one the nutrients have been absorbed it then moves onto the large intestine. The large intestine connects to the rectum and is specialised in processing water so that emptying the bowels is easy. The pancreas is responsible for secreting digestive enzymes into the duodenum. These enzymes then break down protein, fats and carbohydrates. The pancreas is also responsible for making insulin and secreting it directly into the bloodstream.The livers main function within the digestive system is to process the nutrients which are absorbed from the small intestine. Bile is secreted from the liver into the small intestine and plays an important role in digesting fat. The liver also detoxifies potentially harmful chemicals and takes raw materials from the intestine and makes various chemicals the body needs to function. The Process The digestive process begins in the mouth; food is broken down by the chewing process and by the salivary enzymes which break starch down into smaller molecules.After being swallowed the food then enters the esophagus which runs from the mouth to the stomach. It forces food from the throat into the stomach using rhythmic movements. When the food reaches the stomach the food is partially digested and mixed with stomach acids to produce chyme. The food then reaches the small intestine where bile, pancreatic enzymes and other digestive enzymes help to break down food. When the food passes through the large intestine some of the water and chemicals are removed from the food. The bacterium in the large intestine helps the digestion process.After the food passes through the large intestine it is stored in the rectum until excreted. Glucose Our bodies main source of energy takes the form of glucose. This type of sugar comes from digesting carbohydrates into a chemical that is easily converted into energy. Most of our glucose comes from digesting the sugars and starch in food such as pasta, rice, fruits, potatoes and grain. The Enzyme Amylase breaks starch down into maltose and simple sugars which are then broken down to glucose in the small intestine.This form of energy then gets absorbed through the small intestine into the bloodstream. The chemical insulin meets the glucose and together they enter cells in the muscles and brain and allow the glucose to power activities. Energy The body has two main energy systems, aerobic and anaerobic energy. Energy is needed for growth, maintenance, activities and exercise. The amount of energy needed by the body is dependent on the intensity and duration of the exercise. Aerobic energy is usually the first to be used when the demand for energy increases.The extra demand for oxygen is met by an increase in the rate of breathing and an increase in blood supply met by an increase in heart rate. When the demand for oxygen by the body can’t be met the body uses anaerobic energy which can produce energy without oxygen. The energy required for aerobic energy is obtained by burning food stores with oxygen. It works by the breakdown of carbohydrate, fatty acids and some amino acids. This form of energy also uses slow twitch fibres and uses oxygen which means the energy can last longer. Anaerobic energy relies on the release of energy from food stores in the body without using any oxygen.This type of energy uses fast twitch fibres and it is used in short bursts intensive activity and results in the accumulation of lactic acid which is a waste product; this can result in muscle fatigue . Muscle fatigue is tiredness which happens when all the energy sources available are burned up and there is a buildup of lactic acid. They body also uses different forms of energy such as electrical energy which is used in the nervous system, chemical energy, kinetic energy, mechanical energy, light energy, sound energy, nuclear energy and heat energy. Anabolism is the process in which organisms make complex molecules and substances from less complex components. Anabolism leads to growth in organisms as molecules are produced from smaller components. This process of growth requires energy and raw components which are produced through catabolism, in which large molecules are broken down into simpler substances and together these processes make up the chemical process metabolism. Anabolism produced nearly all of the chemicals that organisms are composed of and produced proteins, lipids, nucleic acids and other substances which are essential in development, growth, maintenance and repair.Catabolism is essential for the proper functioning of anabolism. Catabolic processes such as digestion are responsible for breaking down large ad complex molecules into simple forms. Anabolism is responsible for building new molecules and catabolism is responsible for breaking down other molecules. Adenosine Tri Phosphate molecules are responsible for a wide range of activities within the cell. They are the main energy providers and main fuel for almost all processes that go on in a cell and also carried the energy which is necessary to facilitate all of the processes of human metabolism.The role of energy in the body is not only needed for muscular activity and movement but is also necessary to circulate blood, lymph and tissue fluid through the body, is necessary for breathing and respiration, is necessary for making new cells, growth and repair and is used to transmit nerve impulses so we are able to respond to changes in the environment. Oxygen + Glucose - Energy + Water + Carbon Dioxide During the process of breathing air is inhaled and carbon dioxide is exhaled, this change of gases occurs in the alveoli. The inhaled oxygen passes into the alveoli and then diffuses into arterial blood.The waste rich blood from the veins releases carbon dioxide into the alveoli which is r eleased through exhaling. The respiratory system provides the body with oxygen which can chemically react with glucose which is a type of sugar which comes from digesting carbohydrates into a chemical which is easily converted into energy. Respiration also removes the carbon dioxide which is produced by the reaction which creates energy. The cardiovascular system is vital to pump the oxygenated blood round the body at a rate which meets the energy requirements.The heart rate will increase to provide the body with more oxygen as the intensity and duration of exercise increases. This oxygen will then react with glucose to provide the body with energy. The liver produces bile that is stored in the gall bladder and is then secreted into the small intestine to help with the process of digestion, bile emulsifies fats breaking the large molecules into smaller pieces. The liver and the kidneys are important in glucose metabolism. The liver converts glucose into glycogen which provides the body with a short term energy store. Long term energy storage is contained in fat cells.The liver also converts glycogen back into glucose for immediate use and releases it into the blood stream for the muscles to use. The kidneys main role is to remove waste products and excess fluids from the body. When the chemical reaction, Oxygen + Glucose - Energy + Water + Carbon Dioxide occurs, the excess water which is produced is removed from the body by the kidneys. The respiratory system and the digestive system interrelate by enabling oxygen and glucose to get into the blood stream so that the chemical reaction Oxygen + Glucose - Energy + Water + Carbon Dioxide can occur to produce energy.The sugar stored produced by this chemical reaction can be converted immediately into energy is used to enable the person to perform tasks or is stored until the energy is needed. The amount of energy that we receive from different types of food is measured in calories. The glucose which is released into the blood stream can be automatically converted into energy; any extra glucose that isn’t needed is converted to glycogen and is stored in the muscle tissues and liver. This stored glucose can be used for energy during aerobic exercise or can be released by the liver when blood glucose levels drop.