Personal Internal Mechanisms - Essay Example

1. Explain why, despite the view of certain teenage boys, it is possible to survive dinner being 15 minutes late. Answer: The body has its own mechanisms for maintaining the blood glucose levels at proper levels. It is possible to survive dinner being 15 minutes late because the glycogen stores in the body, particularly in the liver, are broken down to release glucose into the blood when the blood glucose levels fall. This glucose helps in the maintenance of a normal blood sugar level providing the body with its energy requirements. This means that the body keeps enough energy stores which it uses when there is shortage of nutrients. This stored glycogen is more than enough to meet the requirements of the body for 15 minutes. 2. Going to the dentist can be stressful. Explain why it is therefore a good idea to have a meal (and clean your teeth) before going for your appointment. Answer: There is a release of stress hormones within the body when a person in under stress. These include cortisol and catecholamines. These hormones are mobilizers of glucose. Under stress the glucose is released and this leads to insulin release. The insulin causes the glucose to move inside cells because of the increased levels of hormone. This can lead to hypoglycemia. This is the reason why it is a good idea to have a meal before going to the dentist so that the blood glucose level can be maintained. 3. Explain why trauma leads to weight loss. Answer: During trauma there is damage to the cells of the body. The energy requirement of the body increases. This increase is due to many reasons. The cell turnover rate increases hence there is increased requirement for proteins for making new cells as well as the energy requirement increases because of the additional energy required. This leads to a depletion of the body energy stores. Glycogen stored in the liver is utilized first. Gluconeogenesis also ensues to overcome the energy requirement. Hence the lipids and proteins of the body are also utilized. This accounts for the weight loss seen in trauma. 4. Why is the diet of convalescent patients so important? Answer: Diet is very important in people who are recovering from illness. This is because during illness there is breakdown of cells in the body. When a person is recovering there is greater cell differentiation of cells and utilization of not only proteins, carbohydrates, lipids but also vitamins and minerals which are required by the body. If the diet of these patients is not monitored they can suffer from deficiency conditions of these essential nutrients. This can also compromise the immunity of the patient hence making him susceptible to infections. Therefore the diet of convalescent patients is important. 5. Explain why exercise is important in weight loss programmes. Answer: Exercise is important in weight loss programs because during exercise the body utilizes initially the carbohydrate stores of the body for energy and then it also starts using the lipids stored in the body for the provision of energy. This leads to the utilization of excess fats and glycogen in the body during exercise. This burning of fuels accounts for the quicker weight loss in exercise programs, making it important for these programs. 6. Explain the significance of Cori’s cycle. Answer: The Cori’s cycle is the cycle which is involved in the conversion of lactate and pyruvate to glucose. This cycle is important because pyruvate and lactate in the body is produced by cells which lack mitochondria like the erythrocytes and it is also the product of glucose metabolism in the muscles. These end products are then carried to the liver where they are concerted to glucose again and either stored in the form of glycogen or released into the blood. If this cycle would not function, increased lactate levels would lead to lactic acidosis. This lactate and pyruvate is also essential in times of extreme energy need when they are converted by the liver into glucose by gluconeogenesis to meet the energy requirements of the body. 7. Are different pathways utilized by the muscles and liver when you are engaged in moderate as compared to severe exercise? Answer: Different pathways are employed by the muscles and liver in moderate exercise as compared to sever exercise. In moderate exercise the metabolism in the muscles is mainly aerobic that is in the presence of oxygen. The muscles convert glycogen to glucose and use it to produce pyruvate which is released into the blood and then converted by the liver to form glucose again. This glucose is then transported to muscles for the utilization. The liver not only converts this pyruvate but it also breaks down glycogen to provide for the energy required by muscles. In severe exercise the muscles glucose undergoes anaerobic metabolism leading to production of lactose. The liver glycogen is also broken down to release glucose into the blood for utilization by the muscles. At the same time if there is excess need of glucose, the liver starts with the process of gluconeogenesis as well. This leads to formation of glucose from non carbohydrate sources which include mainly lipids so that the muscles can meet the energy requirement. 8. Would there be any differences in the activity of key enzymes of carbohydrates and fatty acid metabolism in the muscle cells of an Olympic sprinter and an Olympic marathon runner? Explain your reasoning. Answer: Yes there will be a difference in the key enzymes of carbohydrate and fatty acid metabolism in the muscle cells of an Olympic sprinter and an Olympic marathon runner. The Olympic sprinter has to run for a shorter duration of time as compared to a marathon runner. As more energy is required in a shorter duration of time the Olympic sprinter relies basically on anaerobic metabolism. Muscle fibers in marathon runners have higher aerobic activity. Activity of phospho fructokinase and lactate dehydrogenase is high in muscles of sprinters due to their greater need for anerobic carbohydrate metabolism. This is because they need immediate energy. On the other hand in marathon runners who need to run for a longer duration of time aerobic activity predominates. Hence aerobic lipid metabolism as well as carbohydrate metabolism is used. Activity of aerobic enzymes of lipid and carbohydrate metabolism which include hexokinase as well as citrate synthase and carnithine palmitoyl transferase is high in marathon runners. 9. Why are the ketone levels of people with diabetes monitored so carefully. Answer: Ketone levels are monitored carefully in diabetic patients because increased ketone levels can lead to ketonemia and ketonuria. This condition is referred to as ketosis which can prove to be fatal. Ketone bodies are acidic and they can lead to ketoacidosis. This leads to the utilization of the bicarbonates to combat this acidoses. This leads t hyperventilation for the compensation which is referred to as Kussmaul’s breathing. At the same time the ketone bodies are excreted in the urine by forming salts with sodium and potassium. This leads to increase loss of water from the tubules and loss of ions from the body. It leads to decreased ions in the body as well as dehydration along with metabolic acidosis. Increases in intracranial pressure and cerebral edema are also led to. These events can lead to coma and then death. 10. Individuals with cancer show extreme weight loss. Explain this symptom. Answer: Cancer is a condition in which there is abnormal differentiation of cells. This differentiation requires excess proteins which are taken up from the body. These cancer cells also require greater energy because they are rapidly dividing. This continuous demand of energy at all times leads to the utilization of the body stores of energy. The carbohydrates, lipids as well as proteins of the body are being utilized by these active cells. This accounts for the extreme weight loss seen in cancer patients. 11. Explain how the body ensures survival for as long as possible during prolonged starvation. Answer: During starvation the body starts utilizing its energy reserves. It begins with the utilization of liver glycogen which is converted to glucose. Glucose is the only source of energy for the red blood cells and the brain which also uses ketone bodies but not to greater extent. When the body does not obtain its nutrients the lipid breakdown also begins for the process of gluconeogenesis. The fatty acids can be used as a source of energy for the muscles, liver and other cells. Hence the glucose is spared for the brain and red blood cells. Protein catabolism is the last to begin. Though they do not provide too much energy but in prolonged starvation the little amount of energy can also be useful. The production of ketone bodies from the lipids also begins. These ketone bodies can be used by the brain and other body systems for their energy. It is the ketone bodies which provide for the last main source of energy in prolonged starvation. 12. Explain why the body’s response to fasting is the same as that seen in undiagnosed/ unbalanced diabetic patient. Answer: During fasting the lipids of the body become mobilized for providing energy and there is formation of ketone bodies as well. In undiagnosed diabetes, the cells do not respond to insulin or there are low levels of insulin in the body. As insulin is required for the energy of glucose in cells, the cells do not utilize glucose. This leads to release of glucagon. Glucagon leads to the mobilization of the lipids in the body to meet the energy requirement in the cells by gluconeogenesis. If this is still not controlled the formation of ketone bodies also begins. Hence the body’s response to both the conditions is similar. Read More