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What Carries Glucose In The Blood?

Portal Vein

Portal Vein

The vein that carries blood from the abdominal organs to the liver. The portal vein, which measures about 8 centimeters long, begins at the juncture of the superior mesenteric and splenic veins, passes behind the duodenum (the first part of the small intestine), and then divides into right and left branches that supply blood to the right and left lobes of the liver. The portal vein carries nutrients from the digestive tract, as well as insulin from the pancreas, to the liver. In people who don’t have diabetes, this physical arrangement allows the liver to play a key role in helping the body to maintain normal blood glucose levels. When blood glucose levels get too high, the extra insulin the pancreas secretes goes by way of the portal vein to the liver, telling it to take up more glucose from the bloodstream and store it, and to produce less glucose. When blood glucose levels fall, the alpha cells of the pancreas make more of a hormone called glucagon, which goes straight to the liver via the portal vein, telling it to make more glucose. The portal vein also plays an essential role in experimental islet transplantation in people with Type 1 diabetes. Donor islets are infused into the portal vein of transplant recipients. The portal vein carries the islets to the liver’s sinusoids, a network of capillaries, where they take up residence, thrive, and, ideally, secrete insulin just as a healthy pancreas does. Continue reading >>

What Carries Glucose From The Intestine To Other Parts Of The Body?

What Carries Glucose From The Intestine To Other Parts Of The Body?

Basically, blood. But here's a short summary of the glucose's travels around the body. We start with carbohydrates that are ingested and reach your small intestine. Only monosaccharides (like glucose) can be absorbed, however, so the body must break larger carbohydrates down. This the body does via several enzymes, some from the pancreas and the saliva, and some sitting on the top of the intestinal cells. Monosaccharides are water soluble and therefore ready to be absorbed. But here's a snag - simple diffusion isn't an option: glucose is too big to get into the cell easily. The intestine solves the problem by means of a cotransport with sodium. Sodium is actively pumped out the cell into the surrounding space, which lowers the intracellular sodium concentration. This decrease of sodium within the cell causes sodium from the intestine to try to move inward, which the cell allows... for a price. It has to take a glucose molecule with it. (Technically, the transport protein won't transport sodium until it also combines with some other appropriate molecule, like glucose.) Of the two other monosaccharides, galactose's transport is the same, but fructose uses facilitated transport. So, right now we've got the monosaccharides into the intestinal cell. From there, they are free to leave the cell and enter the blood stream - this exit is by means of another transport protein (facilitated transport). They then travel to the liver by the portal blood stream. The liver grabs a lot of it, and the rest is circulated around the body in the systemic blood stream. There's no carrier protein for the monosaccharides; they just float freely within the blood. From now on, let's talk just of glucose, and not of fructose or galactose, etc.. We're entitled to do this, since 80% of the monosacc Continue reading >>

Glucose Uptake

Glucose Uptake

Method of glucose uptake differs throughout tissues depending on two factors; the metabolic needs of the tissue and availability of glucose. The two ways in which glucose uptake can take place are facilitated diffusion (a passive process) and secondary active transport (an active process which depends on the ion-gradient which is established through the hydrolysis of ATP, known as primary active transport). Facilitated diffusion[edit] There are over 10 different types of glucose transporters; however, the most significant for study are GLUT1-4. GLUT1 and GLUT3 are located in the plasma membrane of cells throughout the body, as they are responsible for maintaining a basal rate of glucose uptake. Basal blood glucose level is approximately 5mM (5 millimolar). The Km value (an indicator of the affinity of the transporter protein for glucose molecules; a low Km value suggests a high affinity) of the GLUT1 and GLUT3 proteins is 1mM; therefore GLUT1 and GLUT3 have a high affinity for glucose and uptake from the bloodstream is constant. GLUT2 in contrast has a high Km value (15-20mM) and therefore a low affinity for glucose. They are located in the plasma membranes of hepatocytes and pancreatic beta cells (in mice, but GLUT1 in human beta cells; see Reference 1). The high Km of GLUT2 allows for glucose sensing; rate of glucose entry is proportional to blood glucose levels. GLUT4 transporters are insulin sensitive, and are found in muscle and adipose tissue. As muscle is a principal storage site for glucose and adipose tissue for triglyceride (into which glucose can be converted for storage), GLUT4 is important in post-prandial uptake of excess glucose from the bloodstream. Moreover, several recent papers show that GLUT 4 is present in the brain also. The drug Metformin phosphor Continue reading >>

Chapter 8 Homeostasis Of Blood Sugar And Gas Concentrations

Chapter 8 Homeostasis Of Blood Sugar And Gas Concentrations

- Blood sugar levels refer to how much sugar is in a person's blood stream. -energy released from glucose molecules by cellular respiration, therefore glucose must be in a constant supply and must be able to enter the cells: -carbs in food broken down during digestion (mechanical and chemical) into glucose and absorbed into blood through walls of small intestine (villi) -after meal, blood glucose levels can rise sharply, thus homeostasis mechanism operate to reduce its conc. to normal -excess glucose removed and stored for use in cellular activities b/w meals -Glucose is required by all cells in order for the process of respiration to take place. -glucose stored as glycogen, molecule made of glucose -form in which carbs stored in body, mainly in liver and muscle cells -pancreas and adrenal glands secrete hormones that affect level of glucose in blood. -liver stores glycogen, from which glucose can be made and added to blood; or glucose can be removed and stored as glycogen Glucose->Blood sugar level high (e.g. after meal)-> glycogen->blood sugar level low (e.g. during exercise)-> glucose -liver cells convert glucose into glycogen for storage, or glycogen to glucose for release into blood in b/w meals, regulating glucose levels -most of its blood supply comes from hepatic portal vein, which brings blood directly from stomach, spleen, pancreas and small and large intestines. Thus, liver has 1st chance to absorb nutrients from digested food -after a meal w/ high carb proportion consumed, breakdown of products, mainly glucose, are absorbed into blood capillaries of villi of small intestine. Hepatic portal vein carries glucose to liver, where: --glucose may be removed from blood by liver (absorbed) to provide energy for liver functioning --may be removed by liver and/or mus Continue reading >>

Facilitated Diffusion And Active Transport Of Glucose

Facilitated Diffusion And Active Transport Of Glucose

Concept 4 Review Whether a cell uses facilitated diffusion or active transport depends on the specific needs of the cell. For example, the sugar glucose is transported by active transport from the gut into intestinal epithelial cells, but by facilitated diffusion across the membrane of red blood cells. Why? Consider how different these two environments are. Epithelial cells lining the gut need to bring glucose made available from digestion into the body and must prevent the reverse flow of glucose from body to gut. We need a mechanism to ensure that glucose always flows into intestinal cells and gets transported into the bloodstream, no matter what the gut concentration of glucose. Imagine what would happen if this were not so, and intestinal cells used facilitated diffusion carriers for glucose. Immediately after you ate a candy bar or other food rich in sugar, the concentration of glucose in the gut would be high, and glucose would flow "downhill" from the gut into your body. But an hour later, when your intestines were empty and glucose concentrations in the intestines were lower than in your blood and tissues, facilitated diffusion carriers would allow the glucose in blood and tissues to flow "downhill," back into the gut. This would quickly deplete your short-term energy reserves. Because this situation would be biologically wasteful and probably lethal, it is worth the additional energy cost of active transport to make sure that glucose transport is a one-way process. By contrast, erythrocytes (red blood cells) and most other tissues in your body move glucose by facilitated diffusion carriers, not by active transport. Facilitated diffusion makes sense in this context because the environment is different for red blood cells and the gut. Whereas the gut experiences Continue reading >>

How The Body Controls Blood Sugar - Topic Overview

How The Body Controls Blood Sugar - Topic Overview

The bloodstream carries glucose-a type of sugar produced from the digestion of carbohydrates and other foods-to provide energy to cells throughout the body. Unused glucose is stored mainly in the liver as glycogen. Insulin, glucagon, and other hormone levels rise and fall to keep blood sugar in a normal range. Too little or too much of these hormones can cause blood sugar levels to fall too low (hypoglycemia) or rise too high (hyperglycemia). Normally, blood glucose levels increase after you eat a meal. When blood sugar rises, cells in the pancreas release insulin, causing the body to absorb glucose from the blood and lowering the blood sugar level to normal. When blood sugar drops too low, the level of insulin declines and other cells in the pancreas release glucagon, which causes the liver to turn stored glycogen back into glucose and release it into the blood. This brings blood sugar levels back up to normal. Continue reading >>

Bbc - Gcse Bitesize Science - Circulation : Revision, Page 3

Bbc - Gcse Bitesize Science - Circulation : Revision, Page 3

The blood transports many useful chemicals around the body. For example, glucose [glucose: A simple sugar made by the body from food, which is used by cells to make energy in respiration.] and oxygen are needed by all cells for aerobic respiration [aerobic respiration: Respiration that requires oxygen.]. Carbon dioxide and water are the waste products of respiration and need to be transported to the lungs so that they can be excreted [excretion: Removal of metabolic waste from the body.]. In order to see this content you need to have both Javascript enabled and Flash installed. In order to see this content you need to have both Javascript enabled and Flash installed. In order to see this content you need to have both Javascript enabled and Flash installed. Plasma - the liquid part of blood. It transports nutrients (eg glucose), amino acids [amino acid: Complex molecules, which form the building-blocks of proteins.], antibodies [antibody: A protein produced by the body's immune system that attacks foreign organisms (antigens) that get into the body.] and hormones [hormone: Chemical messengers produced in cells or glands and carried by the blood to specific organs in the body.] to tissues that need them. It also transports waste substances: carbon dioxide and water to the lungs, and water and urea to the kidneys. Red blood cells - they transport oxygen, which is bound to haemoglobin [haemoglobin: The red protein found in red blood cells that transports oxygen round the body.]. White blood cells - they are part of the bodys immune system [immune system: The body's defence system against diseases and infections.] and fight infection. Platelets - they stick together when a blood vessel is damaged in order to help form a clot [clot: A clump of platelets and blood cells that Continue reading >>

Blood Sugar Or Blood Glucose: What Does It Do?

Blood Sugar Or Blood Glucose: What Does It Do?

Blood sugar, or blood glucose, is sugar that the bloodstream carries to all the cells in the body to supply energy. Blood sugar or blood glucose measurements represent the amount of sugar being transported in the blood during one instant. The sugar comes from the food we eat. The human body regulates blood glucose levels so that they are neither too high nor too low. The blood's internal environment must remain stable for the body to function. This balance is known as homeostasis. The sugar in the blood is not the same as sucrose, the sugar in the sugar bowl. There are different kinds of sugar. Sugar in the blood is known as glucose. Blood glucose levels change throughout the day. After eating, levels rise and then settle down after about an hour. They are at their lowest point before the first meal of the day, which is normally breakfast. How does sugar get into the body's cells? When we eat carbohydrates, such as sugar, or sucrose, our body digests it into glucose, a simple sugar that can easily convert to energy. The human digestive system breaks down carbohydrates from food into various sugar molecules. One of these sugars is glucose, the body's main source of energy. The glucose goes straight from the digestive system into the bloodstream after food is consumed and digested. But glucose can only enter cells if there is insulin in the bloodstream too. Without insulin, the cells would starve. After we eat, blood sugar concentrations rise. The pancreas releases insulin automatically so that the glucose enters cells. As more and more cells receive glucose, blood sugar levels return to normal again. Excess glucose is stored as glycogen, or stored glucose, in the liver and the muscles. Glycogen plays an important role in homeostasis, because it helps our body function du Continue reading >>

What Is Insulin?

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 >>

Must Read Articles Related To High Blood Sugar (hyperglycemia)

Must Read Articles Related To High Blood Sugar (hyperglycemia)

A A A High Blood Sugar (Hyperglycemia) Whenever the glucose (sugar) level in one's blood rises high temporarily, this condition is known as hyperglycemia. The opposite condition, low blood sugar, is called hypoglycemia. Glucose comes from most foods, and the body uses other chemicals to create glucose in the liver and muscles. The blood carries glucose (blood sugar) to all the cells in the body. To carry glucose into the cells as an energy supply, cells need help from insulin. Insulin is a hormone made by the pancreas, an organ near the stomach. The pancreas releases insulin into the blood, based upon the blood sugar level. Insulin helps move glucose from digested food into cells. Sometimes, the body stops making insulin (as in type 1 diabetes), or the insulin does not work properly (as in type 2 diabetes). In diabetic patients, glucose does not enter the cells sufficiently, thus staying in the blood and creating high blood sugar levels. Blood sugar levels can be measured in seconds by using a blood glucose meter, also known as a glucometer. A tiny drop of blood from the finger or forearm is placed on a test strip and inserted into the glucometer. The blood sugar (or glucose) level is displayed digitally within seconds. Blood glucose levels vary widely throughout the day and night in people with diabetes. Ideally, blood glucose levels range from 90 to 130 mg/dL before meals, and below 180 mg/dL within 1 to 2 hours after a meal. Adolescents and adults with diabetes strive to keep their blood sugar levels within a controlled range, usually 80-150 mg/dL before meals. Doctors and diabetes health educators guide each patient to determine their optimal range of blood glucose control. When blood sugar levels remain high for several hours, dehydration and more serious complicat Continue reading >>

The Liver And Blood Glucose Levels

The Liver And Blood Glucose Levels

Tweet Glucose is the key source of energy for the human body. Supply of this vital nutrient is carried through the bloodstream to many of the body’s cells. The liver produces, stores and releases glucose depending on the body’s need for glucose, a monosaccharide. This is primarily indicated by the hormones insulin - the main regulator of sugar in the blood - and glucagon. In fact, the liver acts as the body’s glucose reservoir and helps to keep your circulating blood sugar levels and other body fuels steady and constant. How the liver regulates blood glucose During absorption and digestion, the carbohydrates in the food you eat are reduced to their simplest form, glucose. Excess glucose is then removed from the blood, with the majority of it being converted into glycogen, the storage form of glucose, by the liver’s hepatic cells via a process called glycogenesis. Glycogenolysis When blood glucose concentration declines, the liver initiates glycogenolysis. The hepatic cells reconvert their glycogen stores into glucose, and continually release them into the blood until levels approach normal range. However, when blood glucose levels fall during a long fast, the body’s glycogen stores dwindle and additional sources of blood sugar are required. To help make up this shortfall, the liver, along with the kidneys, uses amino acids, lactic acid and glycerol to produce glucose. This process is known as gluconeogenesis. The liver may also convert other sugars such as sucrose, fructose, and galactose into glucose if your body’s glucose needs not being met by your diet. Ketones Ketones are alternative fuels that are produced by the liver from fats when sugar is in short supply. When your body’s glycogen storage runs low, the body starts conserving the sugar supplies fo Continue reading >>

How Is Glucose Transported In The Circulatory System?

How Is Glucose Transported In The Circulatory System?

Simple sugars and starches are both carbohydrates, and both contain the molecule glucose, which is also called blood sugar. Glucose is a very important biological molecule, as it is the brain's primary source of energy and a significant source of energy for all body cells. The circulatory system helps move glucose out of the digestive tract and into the body cells. Video of the Day The major function of the biomolecule glucose is to provide energy to cells. Body cells take up glucose from the blood and chemically burn it, yielding energy molecules that they can use to fulfill cellular functions. Some cells, such as those of the liver and muscles, store glucose and release it under fasting conditions. In their book "Biochemistry," Drs. Mary Campbell and Shawn Farrell describe glucose as the most ubiquitous of the carbohydrate molecules. Transport Problems To move glucose from the digestive tract, where it is located after a meal, into the body cells, where it's utilized, the glucose has to cross several cell membranes. Since glucose is water soluble while cell membranes are made of fatty material, glucose can't move across cell membranes on its own. Instead, explains Dr. Lauralee Sherwood in her text, "Human Physiology," transporter molecules must ferry it in and out of cells. Glucose does dissolve readily in the bloodstream, however. Glucose first moves into the bloodstream upon absorption from the intestine. Specialized cellular transporters called sodium-dependent hexose transporters shuttle glucose across the cells that line the intestinal tract, explain Drs. Campbell and Farrell. Once through the intestinal lining, glucose is free to dissolve in the blood, and travels around the body. The intestinal transporters act quickly, such that blood glucose rises rapidly aft Continue reading >>

Blood Sugar

Blood Sugar

Blood sugar, or glucose, is the main sugar found in your blood. It comes from the food you eat, and is your body's main source of energy. Your blood carries glucose to all of your body's cells to use for energy. Diabetes is a disease in which your blood sugar levels are too high. Over time, having too much glucose in your blood can cause serious problems. Even if you don't have diabetes, sometimes you may have problems with blood sugar that is too low or too high. Keeping a regular schedule of eating, activity, and taking any medicines you need can help. If you do have diabetes, it is very important to keep your blood sugar numbers in your target range. You may need to check your blood sugar several times each day. Your health care provider will also do a blood test called an A1C. It checks your average blood sugar level over the past three months. If your blood sugar is too high, you may need to take medicines and/or follow a special diet. NIH: National Institute of Diabetes and Digestive and Kidney Diseases Continue reading >>

What Carries Glucose From The Intestine To Other Parts Of The Body ? | Yahoo Answers

What Carries Glucose From The Intestine To Other Parts Of The Body ? | Yahoo Answers

What carries glucose from the intestine to other parts of the body ? Are you sure you want to delete this answer? Best Answer: Glucose is absorbed from the small intestine directly into the blood. It is carried in the plasma of the blood. Glucose is transported via the bloodstream. It is not, however, transported by the red or the white blood cell, it floats by itself. You do NOT test your sugar to see if glucose is there as such. Blood glucose is test for two reasons, to see if it is low and more sugar is needed which is hypoglycemia or to see if there is too much in which case insulin is needed. Glucose in of itself cannot cross the cell membrane alone. It requires the hormone insulin to escort it across. Diabetics do not have an excess of glucose, the reason their readings are high is because they do not have enough insulin to get the glucose into the cells so it therefore continues to float around in the blood. Upload failed. Please upload a file larger than 100x100 pixels We are experiencing some problems, please try again. You can only upload files of type PNG, JPG, or JPEG. You can only upload files of type 3GP, 3GPP, MP4, MOV, AVI, MPG, MPEG, or RM. You can only upload photos smaller than 5 MB. You can only upload videos smaller than 600MB. You can only upload a photo (png, jpg, jpeg) or a video (3gp, 3gpp, mp4, mov, avi, mpg, mpeg, rm). Video should be smaller than 600mb/5 minutes Video should be smaller than 600mb/5 minutes 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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