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In The Time Between Meals, What Organ Releases Glucose To Help Maintain Normal Blood Glucose Levels?

What Organ Regulates The Amount Of Glucose In The Bloodstream?

What Organ Regulates The Amount Of Glucose In The Bloodstream?

Glucose in the bloodstream provides the primary fuel for all body tissues. Blood glucose levels are highest during the digestive period after a meal. Your blood sugar is lowest when the stomach and intestines are empty. Under normal circumstances, the body tightly controls the amount of insulin in your blood. An organ called the pancreas, which is tucked behind the stomach releases the hormones insulin and glucagon to regulate blood sugar levels. Blood sugar regulation is crucial because high and low blood glucose can cause health problems. The pancreas is an elongated organ wide on one end and slender on the other end and measures about 25 centimeters in length. It has dual functions: it releases digestive enzymes, which plays a role in digestion, and it secretes hormones. Prevents High Blood Glucose Insulin plays an integral role in preventing high blood sugar. After you eat a meal and your blood-glucose rises, your pancreas senses your blood-sugar level. When the glucose in your bloodstream becomes high, the pancreas releases insulin into your bloodstream. A small clump of pancreatic cells called the ''islets of Langerhans,'' manufacture insulin. Once the insulin is in your bloodstream, it allows your cells to absorb and use glucose as a fuel source. Mediates Low Blood Sugar When you consume more carbohydrate than your body needs at the time, your body stores the extra glucose as glycogen in the liver. The pancreas continuously monitors your blood sugar levels. When glucose is low, the pancreas releases the hormone glucagon. The glucagon triggers the liver to break down glycogen and converts it back to glucose. The stored glucose enters the bloodstream and raises blood-glucose levels. This allows the body to keep blood sugar levels stable in between meals. Blood Gluc Continue reading >>

You And Your Hormones

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 >>

This Is Exactly What Happens To Your Body When You Eat A Ton Of Sugar

This Is Exactly What Happens To Your Body When You Eat A Ton Of Sugar

As mouth-watering as a sugar-laden sundae or icing-topped cupcake is, we should all know by now that sugar isn't exactly healthy. In fact, it may be one of the worst things you can eat (that is, if you're trying to live a long, healthy life). One study from UC San Francisco actually found that drinking sugary drinks like soda can age your body on a cellular level as quickly as cigarettes. The way the sweet stuff impacts your body is way more complex than just causing weight gain. In fact, when you eat a ton of sugar, almost every part of your body feels the strain—and that's bad news for your health in both the short term and especially the long term. From an initial insulin spike to upping your chances of kidney failure down the road, this is what really happens in your body when you load up on sugar. Your brain responds to sugar the same way it would to cocaine. Eating sugar creates a surge of feel-good brain chemicals dopamine and serotonin. So does using certain drugs, like cocaine. And just like a drug, your body craves more after the initial high. "You then become addicted to that feeling, so every time you eat it you want to eat more," explains Gina Sam, M.D., M.P.H., director of the Gastrointestinal Motility Center at The Mount Sinai Hospital. Your insulin spikes to regulate your blood sugar. "Once you eat glucose, your body releases insulin, a hormone from your pancreas," Dr. Sam explains. The insulin's job is to absorb the excess glucose in the blood and stabilize sugar levels. And a little while later you get that familiar sugar crash. Once the insulin does its job, your blood sugar drops again. Which means you've just experienced a sugar rush, and then a drastic drop, leaving you feeling drained. "That's the feeling you get when you've gone to the buffet a Continue reading >>

The Liver & Blood Sugar

The Liver & Blood Sugar

During a meal, your liver stores sugar for later. When you’re not eating, the liver supplies sugar by turning glycogen into glucose in a process called glycogenolysis. The liver both stores and produces sugar… The liver acts as the body’s glucose (or fuel) reservoir, and helps to keep your circulating blood sugar levels and other body fuels steady and constant. The liver both stores and manufactures glucose depending upon the body’s need. The need to store or release glucose is primarily signaled by the hormones insulin and glucagon. During a meal, your liver will store sugar, or glucose, as glycogen for a later time when your body needs it. The high levels of insulin and suppressed levels of glucagon during a meal promote the storage of glucose as glycogen. The liver makes sugar when you need it…. When you’re not eating – especially overnight or between meals, the body has to make its own sugar. The liver supplies sugar or glucose by turning glycogen into glucose in a process called glycogenolysis. The liver also can manufacture necessary sugar or glucose by harvesting amino acids, waste products and fat byproducts. This process is called gluconeogenesis. When your body’s glycogen storage is running low, the body starts to conserve the sugar supplies for the organs that always require sugar. These include: the brain, red blood cells and parts of the kidney. To supplement the limited sugar supply, the liver makes alternative fuels called ketones from fats. This process is called ketogenesis. The hormone signal for ketogenesis to begin is a low level of insulin. Ketones are burned as fuel by muscle and other body organs. And the sugar is saved for the organs that need it. The terms “gluconeogenesis, glycogenolysis and ketogenesis” may seem like compli Continue reading >>

How Does Your Blood Sugar Work?

How Does Your Blood Sugar Work?

If you're new here, you may want to subscribe to my RSS feed. Thanks for visiting! What on earth is blood sugar and why does it matter? I realize some people may not even understand what their bodies blood sugar does or why it matters. Perhaps you only think someone who is diabetic needs to worry about their blood sugar, but that’s not actually true. We all need to have balanced blood sugar levels or we could potentially end up diabetic as well. Our blood sugar is a key foundation of our overall health, so many functions in the body depend on healthy blood sugar. Blood sugar balance (or blood glucose level) is one of the 2 most tightly regulated systems in the body, with the other being blood pH. Having a normal healthy functioning blood sugar is key to optimal health, regulating so many functions within the body. Normal blood sugar range is between 80 to 100 mg/dL with 89.9 mg/dL as a good baseline, some suggest even lower levels are optimal such as 70-85. ‘The lower you can maintain your blood glucose levels in a healthy and functional way, without experiencing low-blood-sugar symptoms, the better off you are. Those people who are optimally healthy should maintain a range between 70 and 85 mg/dL or lower; this is equivalent to no more than 1 teaspoon of sugar, or about 5 g or 20 kcal, total. Keep in mind that the body is adamant about maintaining the minimal necessary levels of glucose at any given time because glucose is inherently damaging to vessels, organs and tissues in the body. The less glucose that is absolutely necessary the better.’ ~ Nora Gedgaudas,’Primal Body, Primal Mind‘ When we eat a meal, the nutrients in that meal (proteins, fats, carbohydrates) are broken down by the digestive system. The starches from carbohydrates convert to glucose. The Continue reading >>

Homeostasis Of Glucose Levels: Hormonal Control And Diabetes

Homeostasis Of Glucose Levels: Hormonal Control And Diabetes

Homeostasis According to the Centers for Disease Control and Prevention, there are almost 26 million people in the United States alone that have diabetes, which is 8.3% of the total U.S. population. With so many Americans suffering from diabetes, how do we treat all of them? Do all of these people now need insulin shots, or are there other ways to treat, or prevent, diabetes? In order to answer these questions, we must first understand the fundamentals of blood glucose regulation. As you may remember, homeostasis is the maintenance of a stable internal environment within an organism, and maintaining a stable internal environment in a human means having to carefully regulate many parameters, including glucose levels in the blood. There are two major ways that signals are sent throughout the body. The first is through nerves of the nervous system. Signals are sent as nerve impulses that travel through nerve cells, called neurons. These impulses are sent to other neurons, or specific target cells at a specific location of the body that the neuron extends to. Most of the signals that the human body uses to regulate body temperature are sent through the nervous system. The second way that signals can be sent throughout the body is through the circulatory system. These signals are transmitted by specific molecules called hormones, which are signaling molecules that travel through the circulatory system. In this lesson, we'll take a look at how the human body maintains blood glucose levels through the use of hormone signaling. Homeostasis of Blood Glucose Levels Glucose is the main source of fuel for the cells in our bodies, but it's too big to simply diffuse into the cells by itself. Instead, it needs to be transported into the cells. Insulin is a hormone produced by the panc Continue reading >>

Blood Sugar Regulation

Blood Sugar Regulation

Ball-and-stick model of a glucose molecule Blood sugar regulation is the process by which the levels of blood sugar, primarily glucose, are maintained by the body within a narrow range. This tight regulation is referred to as glucose homeostasis. Insulin, which lowers blood sugar, and glucagon, which raises it, are the most well known of the hormones involved, but more recent discoveries of other glucoregulatory hormones have expanded the understanding of this process.[1] Mechanisms[edit] Blood sugar regulation the flatline is the level needed the sine wave the fluctuations. Blood sugar levels are regulated by negative feedback in order to keep the body in balance. The levels of glucose in the blood are monitored by many tissues, but the cells in the pancreatic islets are among the most well understood and important. Glucagon[edit] If the blood glucose level falls to dangerous levels (as during very heavy exercise or lack of food for extended periods), the alpha cells of the pancreas release glucagon, a hormone whose effects on liver cells act to increase blood glucose levels. They convert glycogen into glucose (this process is called glycogenolysis). The glucose is released into the bloodstream, increasing blood sugar. Hypoglycemia, the state of having low blood sugar, is treated by restoring the blood glucose level to normal by the ingestion or administration of dextrose or carbohydrate foods. It is often self-diagnosed and self-medicated orally by the ingestion of balanced meals. In more severe circumstances, it is treated by injection or infusion of glucagon. Insulin[edit] When levels of blood sugar rise, whether as a result of glycogen conversion, or from digestion of a meal, a different hormone is released from beta cells found in the Islets of Langerhans in the p 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 >>

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 >>

Energy Metabolism In The Liver

Energy Metabolism In The Liver

Go to: Introduction The liver is a key metabolic organ which governs body energy metabolism. It acts as a hub to metabolically connect to various tissues, including skeletal muscle and adipose tissue. Food is digested in the gastrointestinal (GI) tract, and glucose, fatty acids, and amino acids are absorbed into the bloodstream and transported to the liver through the portal vein circulation system. In the postprandial state, glucose is condensed into glycogen and/or converted into fatty acids or amino acids in the liver. In hepatocytes, free fatty acids are esterified with glycerol-3-phosphate to generate triacylglycerol (TAG). TAG is stored in lipid droplets in hepatocytes or secreted into the circulation as very low-density lipoprotein (VLDL) particles. Amino acids are metabolized to provide energy or used to synthesize proteins, glucose, and/or other bioactive molecules. In the fasted state or during exercise, fuel substrates (e.g. glucose and TAG) are released from the liver into the circulation and metabolized by muscle, adipose tissue, and other extrahepatic tissues. Adipose tissue produces and releases nonesterified fatty acids (NEFAs) and glycerol via lipolysis. Muscle breaks down glycogen and proteins and releases lactate and alanine. Alanine, lactate, and glycerol are delivered to the liver and used as precursors to synthesize glucose (gluconeogenesis). NEFAs are oxidized in hepatic mitochondria through fatty acid β oxidation and generate ketone bodies (ketogenesis). Liver-generated glucose and ketone bodies provide essential metabolic fuels for extrahepatic tissues during starvation and exercise. Liver energy metabolism is tightly controlled. Multiple nutrient, hormonal, and neuronal signals have been identified to regulate glucose, lipid, and amino acid me Continue reading >>

Blood Sugar & Other Hormones

Blood Sugar & Other Hormones

Other hormones also affect blood sugar. Glucagon, amylin, GIP, GLP-1, epinephrine, cortisol, and growth hormone also affect blood sugar levels. There are other hormones other than insulin that affect the blood sugar levels in your body. It is important to know about glucagon, amylin, GIP, GLP-1, epinephrine, cortisol, and growth hormone. Glucagon: Glucagon, made by islet cells (alpha cells) in the pancreas, controls the production of glucose and another fuel, ketones, in the liver. Glucagon is released overnight and between meals and is important in maintaining the body’s sugar and fuel balance. It signals the liver to break down its starch or glycogen stores and helps to form new glucose units and ketone units from other substances. It also promotes the breakdown of fat in fat cells. In contrast, after a meal, when sugar from the ingested food rushes into your bloodstream, your liver doesn’t need to make sugar. The consequence? Glucagon levels fall. Unfortunately, in individuals with diabetes, the opposite occurs. While eating, their glucagon levels rise, which causes blood sugar levels to rise after the meal. WITH DIABETES, GLUCAGON LEVELS ARE TOO HIGH AT MEALTIMES GLP-1 (glucagon-like peptide-1), GIP (glucose-dependent insulinotropic polypeptide) and amylin: GLP-1 (glucagon-like peptide-1), GIP (glucose-dependent insulinotropic polypeptide) and amylin are other hormones that also regulate mealtime insulin. GLP-1 and GIP are incretin hormones. When released from your gut, they signal the beta cells to increase their insulin secretion and, at the same time, decrease the alpha cells’ release of glucagon. GLP-1 also slows down the rate at which food empties from your stomach, and it acts on the brain to make you feel full and satisfied. Amylin: Amylin is released a Continue reading >>

Insulin And Glucagon

Insulin And Glucagon

Acrobat PDF file can be downloaded here. The islets of Langerhans The pancreatic Islets of Langerhans are the sites of production of insulin, glucagon and somatostatin. The figure below shows an immunofluorescence image in which antibodies specific for these hormones have been coupled to differing fluorescence markers. We can therefore identify those cells that produce each of these three peptide hormones. You can see that most of the tissue, around 80 %, is comprised of the insulin-secreting red-colored beta cells (ß-cells). The green cells are the α-cells (alpha cells) which produce glucagon. We see also some blue cells; these are the somatostatin secreting γ-cells (gamma cells). Note that all of these differing cells are in close proximity with one another. While they primarily produce hormones to be circulated in blood (endocrine effects), they also have marked paracrine effects. That is, the secretion products of each cell type exert actions on adjacent cells within the Islet. An Introduction to secretion of insulin and glucagon The nutrient-regulated control of the release of these hormones manages tissue metabolism and the blood levels of glucose, fatty acids, triglycerides and amino acids. They are responsible for homeostasis; the minute-to-minute regulation of the body's integrated metabolism and, thereby, stabilize our inner milieu. The mechanisms involved are extremely complex. Modern medical treatment of diabetes (rapidly becoming "public enemy number one") is based on insight into these mechanisms, some of which are not completely understood. I will attempt to give an introduction to this complicated biological picture in the following section. Somewhat deeper insight will come later. The Basics: secretion Let us begin with two extremely simplified figur Continue reading >>

Glycogenolysis | Biochemistry | Britannica.com

Glycogenolysis | Biochemistry | Britannica.com

Glycogenolysis, process by which glycogen , the primary carbohydrate stored in the liver and muscle cells of animals, is broken down into glucose to provide immediate energy and to maintain blood glucose levels during fasting . Glycogenolysis occurs primarily in the liver and is stimulated by the hormones glucagon and epinephrine (adrenaline). Various enzyme defects can prevent the release of energy by the normal breakdown of glycogen in muscles. Enzymes in which defects may occur include glucose-6-phosphatase (I); lysosomal x-1,4-glucosidase (II); debranching enzyme (III); branching enzyme (IV); muscle phosphorylase (V); liver phosphorylase (VI, VIII, IX, X); and muscle phosphofructokinase (VII). Enzyme defects that can give rise to other carbohydrate diseases include galactokinase (A1); galactose 1-phosphate UDP transferase (A2); fructokinase (B); aldolase (C); fructose 1,6-diphosphatase deficiency (D); pyruvate dehydrogenase complex (E); and pyruvate carboxylase (F). When blood glucose levels fall, as during fasting, there is an increase in glucagon secretion from the pancreas . That increase is accompanied by a concomitant decrease in insulin secretion, because the actions of insulin, which are aimed at increasing the storage of glucose in the form of glycogen in cells, oppose the actions of glucagon. Following secretion, glucagon travels to the liver, where it stimulates glycogenolysis. The vast majority of glucose that is released from glycogen comes from glucose-1-phosphate, which is formed when the enzyme glycogen phosphorylase catalyzes the breakdown of the glycogen polymer . In the liver, kidneys , and intestines , glucose-1-phosphate is converted (reversibly) to glucose-6-phosphate by the enzyme phosphoglucomutase. Those tissues also house the enzyme glucose Continue reading >>

Pancreatic Regulation Of Glucose Homeostasis

Pancreatic Regulation Of Glucose Homeostasis

Go to: The pancreas is an exocrine and endocrine organ The pancreas has key roles in the regulation of macronutrient digestion and hence metabolism/energy homeostasis by releasing various digestive enzymes and pancreatic hormones. It is located behind the stomach within the left upper abdominal cavity and is partitioned into head, body and tail. The majority of this secretory organ consists of acinar—or exocrine—cells that secrete the pancreatic juice containing digestive enzymes, such as amylase, pancreatic lipase and trypsinogen, into the ducts, that is, the main pancreatic and the accessory pancreatic duct. In contrast, pancreatic hormones are released in an endocrine manner, that is, direct secretion into the blood stream. The endocrine cells are clustered together, thereby forming the so-called islets of Langerhans, which are small, island-like structures within the exocrine pancreatic tissue that account for only 1–2% of the entire organ (Figure 1).1 There are five different cell types releasing various hormones from the endocrine system: glucagon-producing α-cells,2 which represent 15–20% of the total islet cells; amylin-, C-peptide- and insulin-producing β-cells,2 which account for 65–80% of the total cells; pancreatic polypeptide (PP)-producing γ-cells,3 which comprise 3–5% of the total islet cells; somatostatin-producing δ-cells,2 which constitute 3–10% of the total cells; and ghrelin-producing ɛ-cells,4 which comprise <1% of the total islet cells. Each of the hormones has distinct functions. Glucagon increases blood glucose levels, whereas insulin decreases them.5 Somatostatin inhibits both, glucagon and insulin release,6 whereas PP regulates the exocrine and endocrine secretion activity of the pancreas.3, 7 Altogether, these hormones regul 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 >>

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