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Biology Assignment 5
Question 1
The pancreas is a large gland, situated in the peritoneal cavity, in the curve of the duodenum. It is the pancreas that is responsible for aiding the body’s endocrine system. (Darlington College 2011). The pancreas releases two endocrine hormones and it is these hormones that ensure the blood glucose levels within the body are constantly controlled. These hormones are glucagon and insulin and they are secreted from tiny clusters of cells within the pancreas, know as the islets of Langerhans. Glucagon is a hyper- glycaemic hormone, secreted by the islets alpha cells. Its main function is to increase the level of glucose in the blood. This is a vital process when blood sugar levels become low. Glucagon stimulates the liver to break down its excess glycogen into glucose. The glucose then passes into the blood stream and the homeostasis of blood glucose level is restored. Insulin is a hypo- glycaemic hormone that is secreted by the islets beta cells, in response to high blood glucose levels. Insulin decreases the level of glucose in the blood by stimulating its uptake by the skeletal muscles, liver and adipose cells. The skeletal muscles uptake glucose, to give energy for movement and the glucose that travels to the liver is converted into glycogen, and stored here until it is needed. The adipose cells use glucose for cell metabolism. Once sufficient glucose has been removed from the blood, the beta cells slow the secretion of insulin, so that homeostasis is again restored. (Glenn, 2005, pg84). Both insulin and glucagon are vital to ensure that the body constantly has enough fuel to supply its cells with the energy needed to enable them to function normally. Question 2

Peter’s normal blood glucose concentration will be approximately 4.2mmol. After he eats his balanced meal his blood sugar levels will rise to around 8.0mmol. This is because Peter’s meal will contain carbohydrates. In response to this rise in blood sugar levels...
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