Insulin is an important polypeptide hormone secreted by the islets of Langerhans in the pancreas that is central to regulate the metabolism of carbohydrates and fats in the human body. Its main role is in the conversion of glucose to glycogen, which lowers the elevated blood glucose to normal levels. (Source, Wiki)

The hormone causes body cells in different organs and tissues (e.g. liver, muscle, and fat tissue) to utilize glucose from blood, storing the restful amount as glycogen in the liver and muscle.It helps controlling the metabolism of foods you eat and levels of glucose in the blood as an authentic “key keeper." (Source, Wiki)

The function of insulin seems rather simple. During digestion, sugar is absorbed into the blood stream and elevated blood sugar levels stimulate the production of insulin in the pancreas. Insulin allows glucose to diffuse from the blood into essential body organs and tissues in order to be utilized for energy. While regulating glucose and glycogen in the liver, insulin also controls blood sugar by promoting protein synthesis in the cells.

There are two reasons the blood glucose to stay unutilized properly by the body cells- a) When insulin is absent (Type 1 diabetes) and 2) In case of relative insuline deficiency or “insulin resistance” (Type 2 diabetes). Type 2 diabetes can also occur as a result of a partial failure of the pancreas. Thus, glucose builds up in the blood, resulting in an excessive amount of circulating blood glucose (hyperglycemia). Even people with diabetes who take oral medication or require insulin injections to control their blood glucose levels can have higher than normal blood insulin. (Source, Wiki)

The phenomena “insulin resistance” occurs when the normal amount of insulin, secreted by the pancreas, is not able to unlock the door to cells. In some cases (about 1/3 of the people with insulin resistance), do not respond to elevated levels of insulin. In metabolic syndrome, the body cells become resistant to normal effects of insulin and the cells do not absorb glucose from the blood properly to use for energy. (Source, Wiki)

In case that a person is affected by metabolic syndrome, his body is becoming resistant to normal levels of insulin secreted by the pancreas, making impossible future utilization of glucose by the mitochondria in the cells. To maintain normal blood glucose, the pancreas secretes additional insulin, but not in sufficient quantities to meet the body’s needs. In order to balance the above disorder, the pancreas keeps producing additional amount of insulin, but as the body is becoming “deaf” to insulin or “insulin-resistant” - the last one cannot be used for future glucose assimilation. (Source, Wiki)

The very mention of the word- examination is enough to drive anyone jittery. The stress of giving a good exam is at peak specifically the night prior to the exam. It is crucial to understand that giving a stress free exam is no challenging task, provided you follow the right mindset and make use of proper revision methods. Here are some ideas that may help you give stress free exams.

First things 1st, you must know all that you need to cover for your examination. Until and unless you have a run down of your syllabus, there is no way you may go ahead with the preparation. To make things easier, just note down a list of things that you need to revise. Now you could go about ticking the topics as you go on covering them.
Keep all the crucial revision stuff handy. When you are in the middle of the process of revision, you may need a lot of things like text books, work books, internet searches and plenty of more. Keeping all these things handy ensures that you may conveniently take a fast glance at all the topics. Even in case some information isn't accessible in one source, you can readily switch to another, without wasting any time.

An additional useful tip to revise properly while preparing for your exams is to pen down important points in bullets on A5 cards. Keep on jotting down points as you proceed with your revision. This approach could help you learn critical points comfortably, helping you finish your last minute revisions as well. In addition it can help cure your headache which often erupts as a result of going through the study material often. Having small A5 cards makes the process easier as all what you require to do is to take a quick glance.
Unwind yourself prior to giving an exam. You can't think to score great in your exam if you remain stressed and keep fretting for the same. It is essential to relax yourself totally before you give your exam. Don't fall prey to myths like smoking as stress buster. Smoking won't bring down your stress levels, but will just add to your fitness issues. A few stress busters that can work wonders are deep breathing, meditation, yoga and many more.