Blood Glucose Lab Report

The purpose of a homeostatic system is to maintain steady/stable internal environment at a set point. Glucose is used as a major energy source by most cells in the human body. Cells break down glucose in order to produce ATP (energy), to carry out their cellular processes. Blood glucose concentration is maintained between 3.9-5.6 mmol/L-1. The reason behind this range is due to the fact that people of different ages and genders require different amounts of glucose in their blood to carry out different metabolic processes. For example, a growing teenage boy would require a higher blood glucose concentration in comparison to a middle aged women. Blood glucose concentration must be maintained between this set point range because anything above or below this can cause severe problems. If blood glucose concentration becomes too low the tissues in the body that solely rely on glucose as an energy source are greatly affected, as they need a constant supply of glucose in order to function adequately. These

include the brain and red blood cells, from which low blood glucose concentration can cause disorientation which can lead to seizures and then a coma. Blood supply to vital organs can be affected by blood glucose levels being too high over a period of time, as the blood vessels can get damaged, making it difficult for blood to flow to vital organs. Thus, increasing the risk of heart disease and stroke, as well as, kidney disease and vision problems. If an imbalance occurs in blood glucose concentration a homeostatic negative feedback system is used to bring blood glucose concentration back to the set point.
The blood glucose set point range is 3.9-5.6 mmol/L-1.

This is monitored by the cells within the Islets of Langerhans, which is located in the control (the pancreas). After skipping a meal or tough physical exercise blood glucose concentration decreases. Alpha cells in the islets detect this drop and are stimulated to secrete glucagon. Glucagon is a polypeptide hormone which influences an increase in blood glucose concentration. Glucagon travels through the bloodstream until it reaches glucagon receptors which are predominantly found in the liver, as well as, the kidneys. Glucagon stimulates the breakdown of stored glycogen to be released into the bloodstream as glucose. It also stimulates the conversion of amino acids into glucose and the breakdown of fat into fatty acids. These effectors cause an increase in blood glucose levels back towards the normal. This increase in blood glucose concentration is detected by the alpha cells which then stop the secretion of

glucagon.
The stimulus of a rise in blood glucose concentration can be caused by excessive consumption of carbs. This rise is detected by the beta cells in the islets of Langerhans. Beta cells detect the rise and are stimulated to secrete insulin into the bloodstream. Insulin moves through the bloodstream until it find s an insulin specific receptor to bind to. These are found on the surfaces of liver, muscle and fat cells. Insulin stimulates the uptake of glucose into cells throughout the body such as muscle and fat cells. It also stimulates the conversion of glucose into glycogen. These effectors cause blood glucose levels to drop back towards the normal. This fall is detected by the beta cells which then stop secreting insulin.