You And Your Hormones
What is insulin? Insulin is a hormone made by an organ located behind the stomach called the pancreas. Here, insulin is released into the bloodstream by specialised cells called beta cells found in areas of the pancreas called islets of langerhans (the term insulin comes from the Latin insula meaning island). Insulin can also be given as a medicine for patients with diabetes because they do not make enough of their own. It is usually given in the form of an injection. Insulin is released from the pancreas into the bloodstream. It is a hormone essential for us to live and has many effects on the whole body, mainly in controlling how the body uses carbohydrate and fat found in food. Insulin allows cells in the muscles, liver and fat (adipose tissue) to take up sugar (glucose) that has been absorbed into the bloodstream from food. This provides energy to the cells. This glucose can also be converted into fat to provide energy when glucose levels are too low. In addition, insulin has several other metabolic effects (such as stopping the breakdown of protein and fat). How is insulin controlled? When we eat food, glucose is absorbed from our gut into the bloodstream. This rise in blood glucose causes insulin to be released from the pancreas. Proteins in food and other hormones produced by the gut in response to food also stimulate insulin release. However, once the blood glucose levels return to normal, insulin release slows down. In addition, hormones released in times of acute stress, such as adrenaline, stop the release of insulin, leading to higher blood glucose levels. The release of insulin is tightly regulated in healthy people in order to balance food intake and the metabolic needs of the body. Insulin works in tandem with glucagon, another hormone produced by the pan Continue reading >>
What Is Insulin?
Insulin is a hormone made by the pancreas that allows your body to use sugar (glucose) from carbohydrates in the food that you eat for energy or to store glucose for future use. Insulin helps keeps your blood sugar level from getting too high (hyperglycemia) or too low (hypoglycemia). The cells in your body need sugar for energy. However, sugar cannot go into most of your cells directly. After you eat food and your blood sugar level rises, cells in your pancreas (known as beta cells) are signaled to release insulin into your bloodstream. Insulin then attaches to and signals cells to absorb sugar from the bloodstream. Insulin is often described as a “key,” which unlocks the cell to allow sugar to enter the cell and be used for energy. If you have more sugar in your body than it needs, insulin helps store the sugar in your liver and releases it when your blood sugar level is low or if you need more sugar, such as in between meals or during physical activity. Therefore, insulin helps balance out blood sugar levels and keeps them in a normal range. As blood sugar levels rise, the pancreas secretes more insulin. If your body does not produce enough insulin or your cells are resistant to the effects of insulin, you may develop hyperglycemia (high blood sugar), which can cause long-term complications if the blood sugar levels stay elevated for long periods of time. Insulin Treatment for Diabetes People with type 1 diabetes cannot make insulin because the beta cells in their pancreas are damaged or destroyed. Therefore, these people will need insulin injections to allow their body to process glucose and avoid complications from hyperglycemia. People with type 2 diabetes do not respond well or are resistant to insulin. They may need insulin shots to help them better process Continue reading >>
This article is about the insulin protein. For uses of insulin in treating diabetes, see insulin (medication). Not to be confused with Inulin. Insulin (from Latin insula, island) is a peptide hormone produced by beta cells of the pancreatic islets, and it is considered to be the main anabolic hormone of the body. It regulates the metabolism of carbohydrates, fats and protein by promoting the absorption of, especially, glucose from the blood into fat, liver and skeletal muscle cells. In these tissues the absorbed glucose is converted into either glycogen via glycogenesis or fats (triglycerides) via lipogenesis, or, in the case of the liver, into both. Glucose production and secretion by the liver is strongly inhibited by high concentrations of insulin in the blood. Circulating insulin also affects the synthesis of proteins in a wide variety of tissues. It is therefore an anabolic hormone, promoting the conversion of small molecules in the blood into large molecules inside the cells. Low insulin levels in the blood have the opposite effect by promoting widespread catabolism, especially of reserve body fat. Beta cells are sensitive to glucose concentrations, also known as blood sugar levels. When the glucose level is high, the beta cells secrete insulin into the blood; when glucose levels are low, secretion of insulin is inhibited. Their neighboring alpha cells, by taking their cues from the beta cells, secrete glucagon into the blood in the opposite manner: increased secretion when blood glucose is low, and decreased secretion when glucose concentrations are high. Glucagon, through stimulating the liver to release glucose by glycogenolysis and gluconeogenesis, has the opposite effect of insulin. The secretion of insulin and glucagon into the Continue reading >>
Integration Of Biochemical And Physiologic Effects Of Insulin On Glucose Metabolism.
Abstract The major effects of insulin on tissues are: (1) Carbohydrate metabolism: (a) It increases the rate of transport of glucose across the cell membrane in adipose tissue and muscle, (b) it increases the rate of glycolysis in muscle and adipose tissue, (c) it stimulates the rate of glycogen synthesis in a number of tissues, including adipose tissue, muscle, and liver. It also decreases the rate of glycogen breakdown in muscle and liver, (d) it inhibits the rate of glycogenolysis and gluconeogenesis in the liver. (2) Lipid metabolism: (a) It decreases the rate of lipolysis in adipose tissue and hence lowers the plasma fatty acid level, (b) it stimulates fatty acid and triacylglycerol synthesis in tissues, although only to a minor extent in humans, (c) it increases the rate of very-low-density lipoprotein formation in the liver, (d) it increases the uptake of triglyceride from the blood into adipose tissue and muscle, (e) it decreases the rate of fatty acid oxidation in muscle and liver, (f) it increases the rate of cholesterol synthesis in liver. (3) Protein metabolism: (a) It increases the rate of transport of some amino acids into tissues, (b) it increases the rate of protein synthesis in muscle, adipose tissue, liver, and other tissues, (c) it decreases the rate of protein degradation in muscle (and perhaps other tissues), (d) it decreases the rate of urea formation.--These insulin effects serve to encourage the synthesis of carbohydrate, fat and protein. Continue reading >>
Facts About Diabetes And Insulin
Diabetes is a very common disease, which, if not treated, can be very dangerous. There are two types of diabetes. They were once called juvenile-onset diabetes and adult diabetes. However, today we know that all ages can get both types so they are simply called type 1 and type 2 diabetes. Type 1, which occurs in approximately 10 percent of all cases, is an autoimmune disease in which the immune system, by mistake, attacks its own insulin-producing cells so that insufficient amounts of insulin are produced - or no insulin at all. Type 1 affects predominantly young people and usually makes its debut before the age of 30, and most frequently between the ages of 10 and 14. Type 2, which makes up the remaining 90 percent of diabetes cases, commonly affects patients during the second half of their lives. The cells of the body no longer react to insulin as they should. This is called insulin resistance. In the early 1920s, Frederick Banting, John Macleod, George Best and Bertram Collip isolated the hormone insulin and purified it so that it could be administered to humans. This was a major breakthrough in the treatment of diabetes type 1. Insulin Insulin is a hormone. Hormones are chemical substances that regulate the cells of the body and are produced by special glands. The hormone insulin is a main regulator of the glucose (sugar) levels in the blood. Insulin is produced in the pancreas. To be more specific, it's produced by the beta cells in the islets of Langerhans in the pancreas. When we eat, glucose levels rise, and insulin is released into the bloodstream. The insulin acts like a key, opening up cells so they can take in the sugar and use it as an energy source. Sugar is one of the top energy sources for the body. The body gets it in many forms, but mainly as carbohydr Continue reading >>
What Are The Side Effects Of Insulin Shots?
Insulin is at the center of the diabetes problem. In people with type 2 diabetes, the body does not use insulin effectively. The pancreas compensates by overproducing insulin, and in time, it simply cannot keep up with the demands of the body to keep glucose levels down. To provide enough insulin to the body to manage blood glucose levels, many diabetics are advised to take insulin shots. The insulin in these injections is a chemical that is produced artificially to resemble the insulin made in our pancreas. This insulin works just like natural insulin by escorting sugar from our blood into our cells. Type 2 diabetics deal with a condition known as insulin resistance. It is a phenomenon where cells aren’t sensitive to the action of insulin (escorting blood glucose into cells) and hence, do not respond to it. This leads to the accumulation of glucose in the blood and is called hyperglycemia. Supplemental insulin given to Type 2 diabetics helps the body ‘muscle’ sugar out of the bloodstream and into cells. Insulin injections are used to regulate blood sugar differently for the different diabetes-types: For people who have type 1 diabetes – Their bodies cannot make insulin and therefore they aren’t able to regulate the amount of glucose in their bloodstream. For people who have type 2 diabetes – Their bodies aren’t able to produce enough insulin, or use it effectively. The insulin shots are used because the blood sugar cannot be regulated with oral medications alone. They also stop the liver from producing more sugar. Every type of insulin available in a drug store works in this way. They, mainly, differ in two ways – How quickly they begin to work For how long they can regulate blood sugar levels Mechanism of Action Regulating the process in which glucose Continue reading >>
Insulin's Role In The Human Body
Insulin is a hormone produced by the pancreas that has a number of important functions in the human body, particularly in the control of blood glucose levels and preventing hyperglycemia. It also has an effect on several other areas of the body, including the synthesis of lipids and regulation of enzymatic activity. Insulin and Metabolic Processes The most important role of insulin in the human body is its interaction with glucose to allow the cells of the body to use glucose as energy. The pancreas usually produces more insulin in response to a spike in blood sugar level, for example after eating a meal high in energy. This is because the insulin acts as a “key” to open up the cells in the body and allows the glucose to be used as an energy source. Additionally, when there is excess glucose in the bloodstream, known as hyperglycemia, insulin encourages the storage of glucose as glycogen in the liver, muscle and fat cells. These stores can then be used at a later date when energy requirements are higher. As a result of this, there is less insulin in the bloodstream, and normal blood glucose levels are restored. Insulin stimulates the synthesis of glycogen in the liver, but when the liver is saturated with glycogen, an alternative pathway takes over. This involves the uptake of additional glucose into adipose tissue, leading to the synthesis of lipoproteins. Results Without Insulin In the absence of insulin, the body is not able to utilize the glucose as energy in the cells. As a result, the glucose remains in the bloodstream and can lead to high blood sugar, known as hyperglycemia. Chronic hyperglycemia is characteristic of diabetes mellitus and, if untreated, is associated with severe complications, such as damage to the nervous system, eyes, kidneys and extremitie Continue reading >>
Insulin And Insulin Resistance
Go to: Abstract As obesity and diabetes reach epidemic proportions in the developed world, the role of insulin resistance and its consequences are gaining prominence. Understanding the role of insulin in wide-ranging physiological processes and the influences on its synthesis and secretion, alongside its actions from the molecular to the whole body level, has significant implications for much chronic disease seen in Westernised populations today. This review provides an overview of insulin, its history, structure, synthesis, secretion, actions and interactions followed by a discussion of insulin resistance and its associated clinical manifestations. Specific areas of focus include the actions of insulin and manifestations of insulin resistance in specific organs and tissues, physiological, environmental and pharmacological influences on insulin action and insulin resistance as well as clinical syndromes associated with insulin resistance. Clinical and functional measures of insulin resistance are also covered. Despite our incomplete understanding of the compl Continue reading >>
What Is Insulin?
Insulin is a hormone; a chemical messenger produced in one part of the body to have an action on another. It is a protein responsible for regulating blood glucose levels as part of metabolism.1 The body manufactures insulin in the pancreas, and the hormone is secreted by its beta cells, primarily in response to glucose.1 The beta cells of the pancreas are perfectly designed "fuel sensors" stimulated by glucose.2 As glucose levels rise in the plasma of the blood, uptake and metabolism by the pancreas beta cells are enhanced, leading to insulin secretion.1 Insulin has two modes of action on the body - an excitatory one and an inhibitory one:3 Insulin stimulates glucose uptake and lipid synthesis It inhibits the breakdown of lipids, proteins and glycogen, and inhibits the glucose pathway (gluconeogenesis) and production of ketone bodies (ketogenesis). What is the pancreas? The pancreas is the organ responsible for controlling sugar levels. It is part of the digestive system and located in the abdomen, behind the stomach and next to the duodenum - the first part of the small intestine.4 The pancreas has two main functional components:4,5 Exocrine cells - cells that release digestive enzymes into the gut via the pancreatic duct The endocrine pancreas - islands of cells known as the islets of Langerhans within the "sea" of exocrine tissue; islets release hormones such as insulin and glucagon into the blood to control blood sugar levels. Islets are highly vascularized (supplied by blood vessels) and specialized to monitor nutrients in the blood.2 The alpha cells of the islets secrete glucagon while the beta cells - the most abundant of the islet cells - release insulin.5 The release of insulin in response to elevated glucose has two phases - a first around 5-10 minutes after g Continue reading >>
How Does A Lack Of Insulin Affect Your Body?
Up Next It is estimated that up to a third of Americans who have diabetes are unaware that they have the disease. One of the more common symptoms of diabetes is a high level of glucose in the blood. This is brought on by the fact that when the body doesn’t produce insulin, the cells are unable to absorb glucose. As a result, it remains in the bloodstream, which winds up pushing up the blood-glucose levels. Fatigue is also associated with diabetes; this symptom is likewise a result of glucose not being absorbed from the bloodstream. Since glucose is the body’s major source of energy, a person will feel tired if his or her body doesn’t have any fuel to burn. When glucose goes unabsorbed by the cells, it leaves the kidneys with more glucose to filter; however, there’s a limit to how much glucose the kidneys are able to filter. As a result, excess glucose will show up in the urine and stay in the tubule lumen. Because this glucose retains water, the result is increased urine flow, which is the cause of another common symptom of diabetes: excess thirst. Higher levels of urine flow make the body lose sodium, which activates the brain’s thirst receptors. Excessive hunger is another symptom associated with diabetes. While it’s still not clear how the brain’s hunger centers are stimulated, one theory is that high glucagon levels might be the cause. Yet, even as you eat more frequently, you start to lose weight. This is because a lack of insulin causes the rate at which fat cells are broken down in the body to increase, which leads to weight loss. Continue reading >>
Physiologic Effects Of Insulin
Stand on a streetcorner and ask people if they know what insulin is, and many will reply, "Doesn't it have something to do with blood sugar?" Indeed, that is correct, but such a response is a bit like saying "Mozart? Wasn't he some kind of a musician?" Insulin is a key player in the control of intermediary metabolism, and the big picture is that it organizes the use of fuels for either storage or oxidation. Through these activities, insulin has profound effects on both carbohydrate and lipid metabolism, and significant influences on protein and mineral metabolism. Consequently, derangements in insulin signalling have widespread and devastating effects on many organs and tissues. The Insulin Receptor and Mechanism of Action Like the receptors for other protein hormones, the receptor for insulin is embedded in the plasma membrane. The insulin receptor is composed of two alpha subunits and two beta subunits linked by disulfide bonds. The alpha chains are entirely extracellular and house insulin binding domains, while the linked beta chains penetrate through the plasma membrane. The insulin receptor is a tyrosine kinase. In other words, it functions as an enzyme that transfers phosphate groups from ATP to tyrosine residues on intracellular target proteins. Binding of insulin to the alpha subunits causes the beta subunits to phosphorylate themselves (autophosphorylation), thus activating the catalytic activity of the receptor. The activated receptor then phosphorylates a number of intracellular proteins, which in turn alters their activity, thereby generating a biological response. Several intracellular proteins have been identified as phosphorylation substrates for the insulin receptor, the best-studied of which is insulin receptor substrate 1 or IRS-1. When IRS-1 is activa Continue reading >>
The Role Of Insulin In The Body
Tweet Insulin is a hormone which plays a key role in the regulation of blood glucose levels. A lack of insulin, or an inability to adequately respond to insulin, can each lead to the development of the symptoms of diabetes. In addition to its role in controlling blood sugar levels, insulin is also involved in the storage of fat. Insulin is a hormone which plays a number of roles in the body’s metabolism. Insulin regulates how the body uses and stores glucose and fat. Many of the body’s cells rely on insulin to take glucose from the blood for energy. Insulin and blood glucose levels Insulin helps control blood glucose levels by signaling the liver and muscle and fat cells to take in glucose from the blood. Insulin therefore helps cells to take in glucose to be used for energy. If the body has sufficient energy, insulin signals the liver to take up glucose and store it as glycogen. The liver can store up to around 5% of its mass as glycogen. Some cells in the body can take glucose from the blood without insulin, but most cells do require insulin to be present. Insulin and type 1 diabetes In type 1 diabetes, the body produces insufficient insulin to regulate blood glucose levels. Without the presence of insulin, many of the body’s cells cannot take glucose from the blood and therefore the body uses other sources of energy. Ketones are produced by the liver as an alternative source of energy, however, high levels of the ketones can lead to a dangerous condition called ketoacidosis. People with type 1 diabetes will need to inject insulin to compensate for their body’s lack of insulin. Insulin and type 2 diabetes Type 2 diabetes is characterised by the body not responding effectively to insulin. This is termed insulin resistance. As a result the body is less able to t Continue reading >>
Diabetes: Understanding The Effects Of Insulin On The Body
The prevalence of diabetes impacts public health significantly. As a fitness professional, you will likely encounter clients who have diabetes. Having a basic understanding of the condition, along with how exercise impacts those with diabetes, will make you more effective in your mission to get people moving. This blog will focus on the role insulin plays within the body and how defects in insulin production, insulin action, or both, may affect your clients. Insulin is a hormone secreted from the pancreas. Its role is to facilitate the uptake and utilization of glucose by the cells and prevent the breakdown of glycogen. In other words, insulin decreases blood sugar levels. Insulin is countered by another hormone secreted from the pancreas called glucagon, which opposes the effects of insulin by increasing blood sugar levels. So when blood glucose levels are high, insulin is released and glucose is removed from the blood to bring levels back down to a normal range. Glucagon is released when blood glucose levels are too low and stimulates the release of glucose from the liver. Both insulin and glucagon work together using opposing actions to keep blood sugar levels within normal ranges. When insulin isn’t being produced or functioning properly, this balancing act between insulin and glucagon no longer occurs and, if untreated, will result in chronically elevated blood glucose levels. A blood glucose level greater than 126 mg/dL is an indicator for diabetes. There are three types of diabetes that are all the result of defective insulin production or action. Type 1 Develops when the body’s immune system destroys the cells responsible for insulin production (i.e., the body does not produce enough insulin) Can develop at any age, but most often occurs in children Requires Continue reading >>
The Effects Of Insulin On The Body
Insulin is a hormone produced by the pancreas. Its function is to allow other cells to transform glucose into energy throughout your body. Without insulin, cells are starved for energy and must seek an alternate source. This can lead to life-threatening complications. The Effects of Insulin on the Body Insulin is a natural hormone produced in the pancreas. When you eat, your pancreas releases insulin to help your body make energy out of sugars (glucose). It also helps you store energy. Insulin is a vital part of metabolism. Without it, your body would cease to function. In type 1 diabetes, the pancreas is no longer able to produce insulin. In Type 2 diabetes, the pancreas initially produces insulin, but the cells of your body are unable to make good use of the insulin (insulin resistance). Uncontrolled diabetes allows glucose to build up in the blood rather than being distributed to cells or stored. This can wreak havoc with virtually every part of your body. Complications of diabetes include kidney disease, nerve damage, eye problems, and stomach problems. People with Type 1 diabetes need insulin therapy to live. Some people with Type 2 diabetes must also take insulin therapy to control blood sugar levels and avoid complications. Insulin is usually injected into the abdomen, but it can also be injected into the upper arms, thighs, or buttocks. Injection sites should be rotated within the same general location. Frequent injections in the same spot can cause fatty deposits that make delivery of insulin more difficult. Some people use a pump, which delivers insulin through a catheter placed underneath the skin of the abdomen. When you eat, food travels to your stomach and small intestines where it is broken down into nutrients. The nutrients are absorbed and distributed v Continue reading >>
What Happens When A Person's Insulin Level Is High?
Insulin, a hormone secreted by your pancreas, helps control the amount of glucose in your blood. Glucose, also called sugar, is your body's main source of energy. The food you eat is converted to glucose and then driven into your body's cells where it can be used as fuel. Insulin plays a major role in this process. Too little or too much insulin affects the amount of glucose available for fuel. Video of the Day Your pancreas releases insulin in response to elevated levels of glucose in your blood. Once insulin reaches the blood, it performs a number of functions, one of which is to facilitate the movement of glucose into muscle cells and fat. There, it is used as energy. It also stimulates the storage of excess glucose as glycogen in muscles and in the liver. Insulin also stops your liver's production of glucose, which is a process called gluconeogenesis, which serves as an important source of energy when you fast. When your insulin level is too high, your blood glucose level may drop to a dangerously low level--a state called hypoglycemia. This is the most important consequence of too much insulin. The American Diabetes Association defines hypoglycemia as a glucose reading less than or equal to 70 mg/dL. Hypoglycemia occurs as a result of insulin increasing the uptake of glucose by your body's cells, blocking gluconeogenesis and increasing the storage of glucose in the liver and muscle. However, if you don't have diabetes and your pancreas functions as it should, it will release a hormone called glucagon to counteract the effects of insulin. Hypoglycemia is an acute complication of diabetes. It may be mild, moderate or severe. Symptoms include fatigue, weakness, confusion, headache, irritability, personality changes, shakiness, dizziness, trouble concentrating, slurred Continue reading >>
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