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How Do Insulin And Glucagon Work Together?

Insulin: How It Works

Insulin: How It Works

Insulin is a hormone that helps your body control the amount of sugar (glucose) in your blood. It is produced by the pancreas, a large gland that is located in the abdomen behind your stomach. How does insulin work? Insulin is produced in the islets of Langerhans (pancreatic islets), which are small isolated clumps of special cells in the pancreas. Insulin works alongside glucagon, another hormone produced by the pancreas, to manage the levels of glucose in your blood. Both insulin and glucagon are secreted directly into your bloodstream, and work together to regulate your blood glucose levels. Insulin should stop your blood sugar from rising too high and glucagon should prevent it from becoming too low. Insulin is produced by the beta cells of the pancreatic islets. Insulin is released when you have just eaten a meal and the level of glucose in your bloodstream is high. It works by stimulating the uptake of glucose into cells, lowering your blood sugar level. Your liver and muscles can take up glucose either for immediate energy or to be stored as glycogen until it’s needed. Glucagon is produced by the alpha cells of the pancreatic islets. It is released when your blood sugar levels are low (for example overnight, or if you have been fasting or exercising). Glucagon stimulates cells in the liver and muscles to convert stored glycogen to glucose. The glucose is then released into the bloodstream, raising your blood sugar level. What is insulin resistance? Insulin resistance is when the liver and muscle cells stop responding properly to insulin. The initial response of the pancreas is to make more insulin to help glucose enter cells, but the pancreas usually cannot keep making more and more insulin to overcome the insulin resistance. Eventually the insulin-producing ce Continue reading >>

You And Your Hormones

You And Your Hormones

What is glucagon? Glucagon is a hormone that is involved in controlling blood sugar (glucose) levels. It is secreted into the bloodstream by the alpha cells, found in the islets of langerhans, in the pancreas. The glucagon-secreting alpha cells surround a core of insulin-secreting beta cells, which reflects the close relationship between the two hormones. Glucagon’s role in the body is to prevent blood glucose levels dropping too low. To do this, it acts on the liver in several ways: It stimulates the conversion of stored glycogen (stored in the liver) to glucose, which can be released into the bloodstream. This process is called glycogenolysis. It promotes the production of glucose from amino acid molecules. This process is called gluconeogenesis. It reduces glucose consumption by the liver so that as much glucose as possible can be secreted into the bloodstream to maintain blood glucose levels. Glucagon also acts on adipose tissue to stimulate the breakdown of fat stores into the bloodstream. How is glucagon controlled? Glucagon works along with the hormone insulin to control blood sugar levels and keep them within set levels. Glucagon is released to stop blood sugar levels dropping too low, while insulin is released to stop blood sugar levels rising too high. Release of glucagon is stimulated by low blood glucose (hypoglycaemia), protein-rich meals and adrenaline (another important hormone for combating low glucose). Release of glucagon is prevented by raised blood glucose and carbohydrate in meals, detected by cells in the pancreas. In the longer-term, glucagon is crucial to the body’s response to lack of food. For example, it encourages the use of stored fat for energy in order to preserve the limited supply of glucose. What happens if I have too much glucagon? Continue reading >>

Leaf: What Is The Pancreas And Why Is It Important?

Leaf: What Is The Pancreas And Why Is It Important?

The pancreas is a gland that is part of vertebrate digestive and endocrine systems 1. Located right in front of the spine, part of it lies behind the stomach and the rest touching the small intestine 2. The pancreas carries out many different functions and based on these functions can be divided into two portions: the exocrine portion and the endocrine portion. The exocrine pancreas makes up most of the physical mass of the pancreas. Cells in this part of the pancreas secrete a juice that contains digestive enzymes. These digestive enzymes help the small intestine digest carbohydrates, proteins, and lipids and aid in the absorption of nutrients 1. The endocrine pancreas is composed of small clusters of endocrine cells called pancreatic islets that secrete hormones. These hormones include insulin, glucagon, somatostatin which inhibits the release of other hormones, and pancreatic polypeptide which regulates what the pancreas itself secretes. This Leaf focuses on insulin and glucagon. Image 1 is a diagram of a pancreas. Image 2 is a photo of a pancreatic islet. Anytime the concentration of glucose (blood sugar) in the blood rises beyond the normal range, insulin is secreted. Insulin primary function is the concentration of glucose in the blood. Some of the ways insulin carries out this function: It stimulates skeletal muscle fibers to: Take up glucose and convert it into glycogen for storage. It acts on liver cells to: Stimulate them to take up glucose from the blood and convert it into glycogen for storage. Inhibit production of the enzymes that break glycogen down into glucose. Inhibit gluconeogenesis; that is, the conversion of fats and proteins into glucose. It acts on cells in the hypothalamus to reduce appetite. As glucose levels in the blood fall, further insulin p Continue reading >>

Why Are Glucagon And Insulin Antagonistic Hormones?

Why Are Glucagon And Insulin Antagonistic Hormones?

Health Medications & Vitamins Both hormones originate in the pancreas, but insulin is made in the beta cells of the pancreas and glucagon is produced by the alpha cells, according to Brown University. Glucagon is only released if blood sugar is low; on the other hand, at least a small amount of insulin is secreted into the bloodstream at all times. Insulin and glucagon work together to maintain homeostasis in blood sugar levels. When the body detects low levels of blood sugar, the pancreas secretes glucagon into the bloodstream. The hormone acts on liver cells to break down glycogen into glucose. In addition, glucagon can stimulate the liver to make new glucose molecules from raw material such as amino acids, as stated by the Biomedical Hypertexts at Colorado State University. The beta cells of the pancreas contain channels in their membranes that can detect glucose, according Kimball's Biology Pages. When a spike in glucose is found, insulin is secreted, causing skeletal muscle and liver and muscle cells to take up glucose and convert it into glycogen. Insulin also arrests the breakdown of glycogen and the synthesis of glucose. Learn more about Medications & Vitamins Continue reading >>

Blood Glucose Regulation

Blood Glucose Regulation

Glucose is needed by cells for respiration. It is important that the concentration of glucose in the blood is maintained at a constant level. Insulin is a hormone produced by the pancreas that regulates glucose levels in the blood. How glucose is regulated Glucose level Effect on pancreas Effect on liver Effect on glucose level too high insulin secreted into the blood liver converts glucose into glycogen goes down too low insulin not secreted into the blood liver does not convert glucose into glycogen goes up Use the animation to make sure you understand how this works. You have an old or no version of flash - you need to upgrade to view this funky content! Go to the WebWise Flash install guide Glucagon – Higher tier The pancreas releases another hormone, glucagon, when the blood sugar levels fall. This causes the cells in the liver to turn glycogen back into glucose which can then be released into the blood. The blood sugar levels will then rise. Now try a Test Bite- Higher tier. Diabetes is a disorder in which the blood glucose levels remain too high. It can be treated by injecting insulin. The extra insulin allows the glucose to be taken up by the liver and other tissues, so cells get the glucose they need and blood-sugar levels stay normal. There are two types of diabetes. Type 1 diabetes Type 1 diabetes is caused by a lack of insulin. It can be controlled by: monitoring the diet injecting insulin People with type 1 diabetes have to monitor their blood sugar levels throughout the day as the level of physical activity and diet affect the amount of insulin required. Type 2 diabetes Type 2 diabetes is caused by a person becoming resistant to insulin. It can be controlled by diet and exercise. There is a link between rising levels of obesity (chronic overweight) and i Continue reading >>

The Role Of Insulin And Glucagon In Digestion

The Role Of Insulin And Glucagon In Digestion

Transcript of The role of insulin and glucagon in digestion The role of insulin and glucagon in digestion What is Insulin and Glucagon Insulin and glucagon are both produced by the pancreas. The production of insulin and glucagon by these pancreatic cells can tell if a person has diabetes or not. Insulin is produced by the beta cells in the pancreas in response to having high blood sugar. After a meal, the amount of insulin let into the blood increases as the blood glucose rises. Glucagon is made by the alpha cells when blood glucose is low. Blood glucose is low in between eating and during exercise. Glucagon's function is to cause the liver to release stored glucose from its cells into the blood. Your not alone! Cliff Scherb is an Ironman Athlete is living with type 1 diabetes. He was diagnosed with diabetes at the age of nine. He races Ironman’s with a triathlon made up of a 3.8km swim, 180.2km bike ride, and 42.2km run, he manages his own coaching business and trains top athletes with diabetes, including the cyclists on Team Type 1 and the Triabetes team. It took a lot of work for Cliff to manage his diabetes and record everything about himself as good as a researcher might but he eventually got to know how his body works and when it needed help during a race. Cliff is just like you, he has diabetes but he can still do what he loves. Live Life If you take care of your diabetes you can lower your risk of getting sick. High blood sugar can harm blood vessels and cause heart attacks. It can also damage organs in the body and cause blindness, kidney failure, loss of toes or feet, gum problems, or loss of teeth. Do not let diabetes stop you! You can do all the things your friends do and live a long and healthy life. Just found out you have diabetes? So you have just fou Continue reading >>

How Insulin And Glucagon Work To Regulate Blood Sugar Levels

How Insulin And Glucagon Work To Regulate Blood Sugar Levels

The pancreas secretes insulin and glucagon, both of which play a vital role in regulating blood sugar levels. The two hormones work in balance. If the level of one hormone is outside the ideal range, blood sugar levels may spike or drop. Together, insulin and glucagon help keep conditions inside the body steady. When blood sugar is too high, the pancreas secretes more insulin. When blood sugar levels drop, the pancreas releases glucagon to bring them back up. Blood sugar and health The body converts carbohydrates from food into sugar (glucose), which serves as a vital source of energy. Blood sugar levels vary throughout the day but, in most instances, insulin and glucagon keep these levels normal. Health factors including insulin resistance, diabetes, and problems with diet can cause a person's blood sugar levels to soar or plummet. Blood sugar levels are measured in milligrams per decilitre (mg/dl). Ideal blood sugar ranges are as follows: Before breakfast - levels should be less than 100 mg/dl for a person without diabetes and 70-130 mg/dl for a person with diabetes. Two hours after meals - levels should be less than 140 mg/dl for a person without diabetes and less than 180 mg/dl for a person with diabetes. Blood sugar regulation Blood sugar levels are a measure of how effectively an individual's body uses glucose. When the body does not convert enough glucose for use, blood sugar levels remain high. Insulin helps the body's cells absorb glucose, lowering blood sugar and providing the cells with the glucose they need for energy. When blood sugar levels are too low, the pancreas releases glucagon. Glucagon forces the liver to release stored glucose, which causes the blood sugar to rise. Insulin and glucagon are both released by islet cells in the pancreas. These cells Continue reading >>

How Insulin And Glucagon Work

How Insulin And Glucagon Work

Insulin and glucagon are hormones that help regulate the levels of blood glucose, or sugar, in your body. Glucose, which comes from the food you eat, moves through your bloodstream to help fuel your body. Insulin and glucagon work together to balance your blood sugar levels, keeping them in the narrow range that your body requires. These hormones are like the yin and yang of blood glucose maintenance. Read on to learn more about how they function and what can happen when they don’t work well. Insulin and glucagon work in what’s called a negative feedback loop. During this process, one event triggers another, which triggers another, and so on, to keep your blood sugar levels balanced. How insulin works During digestion, foods that contain carbohydrates are converted into glucose. Most of this glucose is sent into your bloodstream, causing a rise in blood glucose levels. This increase in blood glucose signals your pancreas to produce insulin. The insulin tells cells throughout your body to take in glucose from your bloodstream. As the glucose moves into your cells, your blood glucose levels go down. Some cells use the glucose as energy. Other cells, such as in your liver and muscles, store any excess glucose as a substance called glycogen. Your body uses glycogen for fuel between meals. Read more: Simple vs. complex carbs » How glucagon works Glucagon works to counterbalance the actions of insulin. About four to six hours after you eat, the glucose levels in your blood decrease, triggering your pancreas to produce glucagon. This hormone signals your liver and muscle cells to change the stored glycogen back into glucose. These cells then release the glucose into your bloodstream so your other cells can use it for energy. This whole feedback loop with insulin and gluca Continue reading >>

Insulin's Mechanism Of Action

Insulin's Mechanism Of Action

Although insulin was the first endocrine hormone to be isolated and identified, its mechanism of action is still only partially understood. Once more, I refer the reader to one of the many excellent textbooks of medical biochemistry for a discussion of the insulin receptor and its interaction with insulin. Let me just state quickly that the hormone binds to its receptor which has both extra and intracellular domains. Binding of insulin to the tetrameric receptor initiates tyrosine protein kinase activity bringing about an autophosphorylation of the intracellular domains of the receptor. This marks the beginning of a phosphorylation cascade. When these processes were first identified in the 1970s, the following cartoon appeared in Trends in Biochemical Sciences (Pierre de Metz, TIBS 1979). It gives a pretty good impression of the frustration that many researches felt at that time. We knew that phosphorylation was involved in insulin's action, but the specific substrates and relationship to physiological processes remained in the dark. Another observation that caused a lot of speculation was that the insulin-receptor complexes merged in the target cell's plasma membrane and gathered at clathrin-coated "pits". These underwent endocytosis and uptake into endosomes where the receptors and insulin parted company. The separated partners were then sent to lysosomes and destruction. Later, it was found that many of the receptors were reused, being sent back to the plasma membrane from the endosomes after a little control-and-reparation visit in the Golgi apparatus. Again, a great cartoon appeared in TIBS showing the state of knowledge at that point (I have added the "receptor return pathway"). Insulin and Glucagon regulate minute to minute metabolism. Our metabolism is controlle Continue reading >>

The Role Of Glucose, Insulin And Glucagon In The Regulation Of Food Intake And Body Weight.

The Role Of Glucose, Insulin And Glucagon In The Regulation Of Food Intake And Body Weight.

Abstract Glucose and related pancreatic hormones play a major role in the metabolism of monogastric mammals yet their influence on hunger and/or satiety is, as yet, poorly understood. Glucose, insulin and glucagon rise during a meal and gradually decline to baseline levels shortly after a meal. A sudden drop in plasma glucose as well as insulin have been reported just prior to the onset of a meal but the functional significance of this is not yet clear. Systemic injections of glucose have no acute satiety effects but intraduodenal and intrahepatic infusions reduce food intake and free-feeding and deprived animals respectively. Treatments which decrease cellular glucose utilization directly (2-DG) or indirectly (insulin) increase food intake while exogenous glucagon (which produces hyperglycemia) decreases it. There is considerable evidence that some or all of these effects may be due to a direct central action of glucose, 2-DG, insulin, and glucagon on brain mechanisms concerned with the regulation of hunger and satiety although influences on peripheral "glucoreceptors" have been demonstrated as well. The functional significance of glucoprivic feeding is, however, questioned. The feeding response to 2-DG and related compounds is capricious, and its temporal course does not parallel the hyperglycemic reaction which presumably reflects cellular glucopenia. Moreover, numerous brain lesions which increase, decrease, or have no effect on ad lib intake and often have no effect on the response to deprivation have been shown to severely impair or abolish feeding responses to systemic injections of 2-DG that produce severe central as well as peripheral glucopenia. Feeding responses to insulin are intact after most of these lesions, suggesting that this hormone may influence food Continue reading >>

Introduction

Introduction

INTRODUCTION Glucose in the blood provides a source of fuel for all tissues of the body. Blood glucose levels are highest during the absorptive period after a meal, during which the stomach and small intestine are breaking down food and circulating glucose to the bloodstream. Blood glucose levels are the lowest during the postabsorptive period, when the stomach and small intestines are empty. Despite having food only periodically in the digestive tract, the body works to maintain relatively stable levels of circulatory glucose throughout the day. The body maintains blood glucose homeostasis mainly through the action of two hormones secreted by the pancreas. These hormones are insulin, which is released when glucose levels are high, and glucagon, which is released when glucose levels are low. The accompanying animation depicts the functions of these hormones in blood glucose regulation. CONCLUSION Throughout the day, the release of insulin and glucagon by the pancreas maintains relatively stable levels of glucose in the blood. During the absorptive period blood glucose levels tend to increase, and this increase stimulates the pancreas to release insulin into the bloodstream. Insulin promotes the uptake and utilization of glucose by most cells of the body. Thus, as long as the circulating glucose supply is high, cells preferentially use glucose as fuel and also use glucose to build energy storage molecules glycogen and fats. In the liver, insulin promotes conversion of glucose into glycogen and into fat. In muscle insulin promotes the use of glucose as fuel and its storage as glycogen. In fat cells insulin promotes the uptake of glucose and its conversion into fats. The nervous system does not require insulin to enable its cells to take up and utilize glucose. If glucose Continue reading >>

Diabetes: Understanding The Effects Of Insulin On The Body

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 >>

How Is Glucagon An Antagonist Of Insulin?

How Is Glucagon An Antagonist Of Insulin?

Insulin and glucagon work together to balance your blood sugar levels, keeping them in the narrow range that your body requires. These hormones are like the yin and yang of blood glucose maintenance. Read on to learn more about how they function and what can happen when they dont work well. Insulin and glucagon work in whats called a negative feedback loop. During this process, one event triggers another, which triggers another, and so on, to keep your blood sugar levels balanced. During digestion, foods that contain carbohydrates are converted into glucose. Most of this glucose is sent into your bloodstream, causing a rise in blood glucose levels. This increase in blood glucose signals your pancreas to produce insulin. The insulin tells cells throughout your body to take in glucose from your bloodstream. As the glucose moves into your cells, your blood glucose levels go down. Some cells use the glucose as energy. Other cells, such as in your liver and muscles, store any excess glucose as a substance called glycogen. Your body uses glycogen for fuel between meals. About four to six hours after you eat, the glucose levels in your blood decrease, triggering your pancreas to produce glucagon. This hormone signals your liver and muscle cells to change the stored glycogen back into glucose. These cells then release the glucose into your bloodstream so your other cells can use it for energy. This whole feedback loop with insulin and glucagon is constantly in motion. It keeps your blood sugar levels from dipping too low, ensuring that your body has a steady supply of energy. Your bodys regulation of blood glucose is an amazing metabolic feat. However, for some people, the process doesnt work properly. Diabetes mellitus is the best known condition that causes problems with bloo Continue reading >>

Glucose Metabolism

Glucose Metabolism

Energy is required for the normal functioning of the organs in the body. Many tissues can also use fat or protein as an energy source but others, such as the brain and red blood cells, can only use glucose. Glucose is stored in the body as glycogen. The liver is an important storage site for glycogen. Glycogen is mobilized and converted to glucose by gluconeogenesis when the blood glucose concentration is low. Glucose may also be produced from non-carbohydrate precursors, such as pyruvate, amino acids and glycerol, by gluconeogenesis. It is gluconeogenesis that maintains blood glucose concentrations, for example during starvation and intense exercise. The endocrine pancreas The pancreas has both endocrine and exocrine functions. The endocrine tissue is grouped together in the islets of Langerhans and consists of four different cell types each with its own function. Alpha cells produce glucagon. Beta cells produce proinsulin. Proinsulin is the inactive form of insulin that is converted to insulin in the circulation. Delta cells produce somatostatin. F or PP cells produce pancreatic polypeptide. Regulation of insulin secretion Insulin secretion is increased by elevated blood glucose concentrations, gastrointestinal hormones and Beta adrenergic stimulation. Insulin secretion is inhibited by catecholamines and somatostatin. The role of insulin and glucagon in glucose metabolism Insulin and glucagon work synergistically to keep blood glucose concentrations normal. Insulin: An elevated blood glucose concentration results in the secretion of insulin: glucose is transported into body cells. The uptake of glucose by liver, kidney and brain cells is by diffusion and does not require insulin. Click on the thumbnail for details of the effect of insulin: Glucagon: The effects of glu Continue reading >>

Glucagon Vs. Insulin: Functions & Feedback Loop

Glucagon Vs. Insulin: Functions & Feedback Loop

Have you ever wondered how sugar from your food gets into your cells? In this lesson, we'll be learning about how two hormones, insulin and glucagon, work together to regulate your blood sugar levels to keep your cells working properly. What Is Blood Glucose? Think about your last meal. It probably had some sort of carbohydrate in it, such as bread or pasta. Bread and pasta have carbohydrates in large form, called polymers. In order for these carbohydrates to get into your blood to be used by cells, the digestive system breaks them down into their individual pieces, called monomers. All carbohydrates, even ones that don't taste sweet, are broken down into simple sugars, usually glucose. Glucose is small enough to be absorbed into the blood stream from your digestive system. There is can be transported to cells in your body for storage or to make energy. In the small intestine, glucose is absorbed into the blood. The amount of glucose you have in your blood at any given time is called your blood-glucose level. Like all things in our body, we need our blood-glucose level to be in balance, or homeostasis. If we have too little glucose our cells won't be able to make energy and we can get tired, dizzy, or even pass out. If we have too much glucose in our blood, such as with diabetes, it can damage our cells, particularly the eyes, nervous system, and kidneys. So, how does your body keep just the right amount of glucose in your blood, particularly after a meal where you are flooded with glucose? The answer is through chemicals called hormones. These chemicals travel all over your body through the blood, sending messages to your cells. Two hormones that regulate blood-glucose levels, insulin and glucagon, are made in the pancreas. Let's look at how each of these hormones work Continue reading >>

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