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What is homeostasisand why is it necessary? Describe the way in which homeostatic control mechanisms function. Using the control of blood sugar as an example.

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What is homeostasis and why is it necessary? Describe the way in which homeostatic control mechanisms function. Using the control of blood sugar as an example. Your account should clearly identify the roles of RECEPTERS, EFFECTORS THE NERVOUS SYSTEM AND THE ENDOCRINE SYSTEM AND EXPLAIN THE PRINCIPLE OF NEGATIVE FEEDBACK. Homeostasis means 'staying the same'. In the body this refers to the way the body maintains a stable internal environment. For an organ to function properly its cells and tissues must experience more or less constant conditions. Each cell is bathed in tissue fluid which is kept within certain physical and chemical limits. The conditions that need to be controlled include temperature, amount of water in the body, amount of glucose and amount of nitrogenous waste. Homeostasis can therefore be described as a condition in which the body's internal environment remains within certain physiological limits. This allows cells to work efficiently despite what is going on outside the body. ...read more.


These hormones pass through the blood to arrive at a target organ which has cells possessing the appropriate receptor. Each receptor is designed to respond to a specific hormone which binds to the receptor on the surface of the cell setting off a series of events within the cell. The pancreatic endocrine system is involved in the control of blood sugar. Blood sugar is also known as blood glucose. It is delivered by the blood stream around the body and is broken down in respiration releasing energy. Blood glucose is maintained in a healthy person at around 800mg per dm3. If the level drops below 600 mg per dm3 a person suffers from hypoglycaemia and can loose consciousness. On the other hand if it rises above the norm it can cause hyperglycaemia resulting in a lack of blood to the heart. The amount of glucose is controlled by the hormones, insulin and glucagons which are produced in the islets of Langerhans in the pancreas. ...read more.


The rate of respiration is also reduced. Diagram to show negative feed back control of blood sugar levels within the body. The cycle continues depending on the levels. The pancreatic endocrine system is more complicated than some as two hormones are involved. It is important that both respond as both have a positive effect to balance the other. It is necessary for insulin production to be decreased and glucagon be produced as if just insulin decreased there would be nothing to cause the liver to respond to breakdown glycogen. The homeostatic control would be lost with severe consequences. Homeostatic control is extremely important. Failure could result in death. Detectors, receptors and effectors all play a crucial role in maintaining a constant environment around the cells. The negative feedback cycle maintains tissue fluid at its norm for a variety of things including temperature, water content, glucose levels, oxygen levels, carbon dioxide levels andb ammonia levels. Chemical changes produced by hormones are slower than changes produced by the central nervous system but allow homeostatic control within a small fluctuation. Jackie Carvell ...read more.

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