e.hormone | Endocrine System : Hormone Glands Endocrine System Hormone Function: Develop & maintain female sex organs & characteristics; Initiates building of uterine lining Hormone Regulator: Follicle-stimulating hormone (FSH) Ovary (Corpus Luteum) Hormone Released: Progesterone & Estrogens Hormone Structure: Steroid Hormone Function: Influences breast development and menstrual cycles; Promotes growth and differentiation of uterine lining; Maintains pregnancy Hormone Regulator: FSH & Luteinizing hormone Hormone Released: Androgens (mainly testosterone) Hormone Structure: Steroid Hormone Function: Develop & maintain male sex organs & characteristics; aid sperm production Hormone Regulator: FSH & LH Hormone Function: Lowers blood sugar; Increases glycogen storage in liver; Stimulates protein synthesis Hormone Regulator: Blood glucose concentrations Hormone Released: Glucagon Hormone Function: Stimulates glycogen breakdown in liver; Increases blood sugar (glucose) concentration Hormone Regulator: Blood glucose & amino acid concentrations Hormone Released: Somatostatin Hormone Function: Suppresses release of insulin & glucagon Hormone Regulator: Nervous

 system, feedback from growth hormone Adrenal Glands (Medulla And Cortex) Hormone Released: Epinephrine (adrenaline) Hormone Structure: Amino Acid Derivative (Catecholamine) Hormone Function: Constricts blood vessels in skin, kidneys and gut which increases blood supply to heart, brain and skeletal muscles and leads to increased heart rate & blood pressure; Stimulates smooth muscle contraction; Raises blood glucose levels which increases available energy Hormone Regulator: Sympathetic nervous system Hormone Released: Norepinephrine (noradrenaline) Hormone Structure: Amino Acid Derivative (Catecholamine) Hormone Function: Constricts blood vessels throughout the body; Increases heart rate & contraction of cardiac muscles; Increases metabolic rate Hormone Regulator: Sympathetic nervous system Hormone Released: Glucocorticoids (mainly cortisol & corticosterone) Hormone Structure: Steroids Hormone Function: Regulates blood glucose concentrations by affecting many aspects of carbohydrate metabolism; Affects growth; Decreases effects of stress and anti-inflammatories Hormone Regulator: Corticotopin- releasing hormone (CRH) from hypthalamus; Adrenocorticotropic hormone

 (ACTH) Hormone Released: Mineralocorticoids (mainly aldosterone) Hormone Structure: Steroid Hormone Function: Regulates sodium, water & potassium excretion by the kidney Hormone Regulator: Renin & Angiotensin Hormone Released: Gonadocorticoids (mainly androgens (male sex hormones)) Hormone Structure: Steroid Hormone Function: Contribute to secondary sex characteristics (particularly after menopause in women) Hormone Regulator: Adrenocorticotropic hormone (ACTH) The Blood Sugar Hormones!

The Blood Sugar Hormones! By Derek Charlebois Last updated: Aug 02, 2011 Hormones are very important in building muscle. Understanding them can give you a boost in your endeavor to better your body. In this article, I will outline two major hormones that play a role in bodybuilding. Hormones are very important in building muscle. Understanding them can give you a boost in your endeavor to better your body. In this article, I will outline two major hormones that play a role in bodybuilding. But first, I'll give you the definition of hormone: " Hormone (n) - a chemical that transfers information and instructions between cells in animals and plants. Often described as the body's chemical messengers, hormones regulate growth and development, control the function of various tissues, support reproductive functions, and regulate metabolism (the process used to break down food to create energy)." 1 So basically, hormones tell your body what it needs to do. RELATED ARTICLE Weight Training And Hormones - The Amazing Connection! Hormones are a busy bunch. From testosterone to cortisol, there is a constant battle going on which should be understandable to the average person. [ Click here to learn more.

] The Hormones Insulin Insulin is a hormone that is made in the pancreas. Insulin's job is to keep blood sugar levels from rising too high. When you intake a carbohydrate (let's say grape juice , for example), your body releases insulin to regulate your blood sugar levels. The body is constantly trying to maintain homeostasis, or internal equilibrium. Therefore, it does not let its blood sugar levels drop too low or become to high. The glucose is transported to muscle tissue and fat cells, lowering blood sugar levels. This is where insulin becomes very important to bodybuilders . Insulin is very anabolic because it increases the body's ability to uptake amino acids .2 It is believed that the best times to create an insulin spike is when you wake up and after a workout . What Does Anabolic Mean? Anabolic refers to the metabolic process that is characterized by molecular growth, such as the increase of muscle mass. Thus, it means "muscle-building" in most common bodybuilding contexts. This is because your insulin sensitivity is highest at these times.2 To create an insulin spike, a food with a high GI rating is needed. An example of this would be honey.

Eating honey , along with your protein shake , will cause an insulin spike and bring glucose to your muscles and increase your amino acid uptake. What Does 'GI' Stand For? GI is an acronym for ' Glycemic Index '. Insulin has also been shown to stop protein breakdown after a workout.6 So insulin replenishes glycogen storage, increases amino acid uptake, and stops protein breakdown. What Is Glycogen? Glycogen is the principal stored form of carbohydrate energy (glucose), which is reserved in muscles. When your muscles are full of glycogen, they look and feel full. Before you start drinking a bottle of honey, however - insulin also has a downside. Insulin also plays a role in storing fat . When insulin is released, it causes the liver to store glucose as glycogen. This is fine when your liver needs its glycogen level replenished, such as after a workout. If the liver is saturated (or already full) of glycogen, however, any extra glucose will be transported to fat cells.4 RELATED ARTICLE Insulin & Supplements: What You Need To Know! I've talked a bit about insulin in the past.

I'm going to review my previous article previously published on Bodybuilding.com before delving into some new info. [ Click here to learn more. ] Glucagon Glucagon is a hormone that is also produced in the pancreas. Its job is also to regulate blood sugar levels. Unlike insulin, however, glucagon is released when blood sugar levels are low.3 In order to raise the body's blood sugar level, glucose is needed. Because there is a shortage of glucose, the body has to turn elsewhere to get it. What Is Glucagon (Not Glycogen)? Glucagon is a hormone produced by the pancreas that stimulates an increase in blood sugar levels, thus opposing the action of insulin. First, glycogen stored in the liver is used. So, where does the glucose come from next? You guessed it, muscle.2 Glucagon stimulates the breakdown of muscle. Muscle breakdown will occur to supply the body with glucose to regulate blood sugar levels. Glucagon History In the 1920s, Kimball and Murlin studied pancreatic extracts and found an additional substance with hyperglycemic properties.

Glucagon was sequenced in the late 1950s, but a more complete understanding of its role in physiology and disease was not established until the 1970s when a specific radioimmunoassay (a scientific method used to test hormone levels in the blood without the need to use a bioassay) was developed. To stop this from happening, you want to eat low GI foods, which will supply your body will glucose without causing the blood to release massive amounts of insulin to absorb it. Desired Blood Sugar Level Your body want to keep its blood sugar level within a certain range. The desired range is between 70 mg/dl and 110 mg/dl ("mg/dl" means "milligrams of glucose per 100 milliliters of blood").5 Summary Insulin can be very anabolic. To use this to your advantage, try to create an insulin spike after your workout. This is the most important time to do this. Another prime time would be when you wake up. You do not want to bombard your body with insulin, however, because it can be fattening. RELATED ARTICLE Hungry, Hungry Hormones.

After all, it seems to me that most exercise and nutrition questions, especially those related to our physiological responses to certain manipulations, are quite complex. Let me explain... [ Click here to learn more. ] It is important not to let your blood sugar level drop too low, also. You do not want to lose muscle just because you are not eating. To keep your body running properly, eat low GI foods during the day. This will keep you body from using muscle protein for energy and releasing large amounts of insulin. References: "Hormone," Microsoft® Encarta® Encyclopedia 99. Copyright © 1993-1998 Microsoft Corporation. Paul Delia, "Insulin, Glucagon, Glucose, Fat and Muscle: Understanding How These Elements Interact Can Help You Build Muscle and Burn Fat." [ link ] "Glucagon," Microsoft® Encarta® Encyclopedia 99. Copyright © 1993-1998 Microsoft Corporation. "Physiologic Effects of Insulin." [ link ] "Insulin Regulation of Blood Sugar and Diabetes." [ link ] John M.

Berardi, "Solving The Post-Workout Puzzle - Part 2: The Recovery Plan." [ link ] Recommend this article to a friend by e-mail by clicking here ! Thanks, Homeostasis - blood sugar and temperature Homeostasis - blood sugar and temperature Select from our full list of topics... A Home / Homeostasis - blood sugar and temperature Homeostasis - blood sugar and temperature 14-16 The temperature in the core of the body; not at the surface of the skin Blood sugar The sugar (glucose) dissolved in the blood; the normal range is 4.0 - 7.8 mmol/l Puberty The time of gradual development of the secondary sexual characteristics and sexual maturity. Insulin A hormone produced by the pancreas. It allows cells in the body to take in and store glucose. Homeostasis The maintenance of a constant internal environment in the body Glucose A type of sugar: a mono saccharide with 6 carbon atoms (a hexose sugar). Glucagon A hormone produced by the pancreas. It causes the liver to convert glycogen back to glucose and to release glucose into the bloodstream. Glossary A list of often difficult or specialised words with their definitions.

Enzymes Reusable protein molecules which act as biological catalysts, changing the rate of chemical reactions in the body without being affected themselves Cells The basic unit from which all living organisms are built up, consisting of a cell membrane surrounding cytoplasm and a nucleus. Homeostasis - Sugar balance and temperature control Homeostasis describes the functions of your body which work to keep your internal environment constant within a very narrow range. Two important aspects of homeostasis are balancing the blood sugar levels and maintaining the body temperature. Your body is made up of millions of cells which need the conditions inside your body to be as constant as possible so they can work properly. However everything you do tends to change your internal conditions. You take millions of new molecules into your body when you eat and digest food. Your blood sugar levels soar after you have a meal - but your cells use up the glucose fast when you exercise hard. You release heat energy every time you move about, the amount of water you take into and lose from your body varies all the time and your cells are constantly producing poisonous waste (see Homeostasis - the kidneys and water balance .) The blood sugar levels in your body are coordinated by hormones, chemicals which regulate and balance the working of organs and cells.

Hormones are made in endocrine glands and are carried around the body to their target organs in the blood stream. Some hormones have long term effects, for example, the hormones that control how you grow and the changes that happen at puberty. Other hormones have shorter term effects. The hormones insulin and glucagon which control your blood sugar levels are like this. It is important that the core temperature of your body stays within a very small range for the enzymes in the cells of your body to work properly. Your skin is one of the most important organs in the control of body temperature. Contents Blood Sugar & Other Hormones :: Diabetes Education Online 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: 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. People with type 1 diabetes have absent or malfunctioning beta cells so the hormones insulin and amylin are missing and the hormone GLP1 cannot work properly. This may explain, in part, why individuals with diabetes do not suppress glucagon during a meal and have high blood sugars after a meal. Amylin: Amylin is released along with insulin from beta cells. It has much the same effect as GLP-1. It decreases glucagon levels, which will then decrease the liver’s glucose production, slows the rate at which food empties from your stomach, and makes your brain feel that you have eaten a full and satisfying meal. The overall effect of these hormones is to reduce the production of sugar by the liver during a meal to prevent it from getting too high. The good news is that amylin is now available as a medicine to control post-meal glucagon and blood sugar in individuals with type 1 diabetes.

(GLP-1 also is available as a medicine but is not approved for use for people with type 1) Epinephrine, cortisol, and growth hormone: Epinephrine, cortisol, and growth hormone are other hormones that help maintain blood sugar levels. They, along with glucagon (see above) are called “stress” or “gluco-counter-regulatory” hormones – which means they make the blood sugar rise. Epinephrine (adrenaline) is released from nerve endings and the adrenals, and acts directly on the liver to promote sugar production (via glycogenolysis). Epinephrine also promotes the breakdown and release of fat nutrients that travel to the liver where they are converted into sugar and ketones. Cortisol is a steroid hormone also secreted from the adrenal gland. It makes fat and muscle cells resistant to the action of insulin, and enhances the production of glucose by the liver. Under normal circumstances, cortisol counterbalances the action of insulin. Under stress or if a synthetic cortisol is given as a medication (such as with prednisone therapy or cortisone injection), cortisol levels become elevated and you become insulin resistant.

When you have Type 1 diabetes, this means your may need to take more insulin to keep your blood sugar under control. Growth Hormone is released from the pituitary, which is a part of the brain. Like cortisol, growth hormone counterbalances the effect of insulin on muscle and fat cells. High levels of growth hormone cause resistance to the action of insulin. Self-assessment Quiz Self assessment quizzes are available for topics covered in this website. To find out how much you have learned about Facts about Diabetes, take our self assessment quiz when you have completed this section. The quiz is multiple choice. Please choose the single best answer to each question. At the end of the quiz, your score will display. If your score is over 70% correct, you are doing very well. If your score is less than 70%, you can return to this section and review the information. How to Build Muscle Fast: Importance of Hormones and Building Muscle Sugar Is Bad If You Consume Too Much Importance of Hormones and Building Muscle Hormones are triggered in your body by practically everything you do. We will cover the most important anabolic and catabolic hormones in the body because they contribute a significant role in your muscle growth.

Hormones are basically chemical messengers secreted by the endocrine system. It is vital to understand how to influence these hormones to maximize fat loss and muscle growth. Not to mention it’s important to understand their effect on our overall health. I will keep this simple and I will not provide an endocrine lesson on these hormones because there is a lot of information. I will be giving the info you need to know only!! Some hormones build muscle while others actually breakdown muscle. Some hormones burn fat while other hormones can actually cause you to store more of it! It’s important than we control our results as much as possible by maximizing the amount of muscle building hormones & fat loss hormones while minimizing the production of muscle breakdown hormones and fat storing hormones. Hormone#1 Insulin Hormone #6: Growth Hormone (GH) Hormone#1 Insulin This hormone is definitely a double edge sword so to speak. Insulin is released by the pancreas and can be either your best friend or worst foe. It is great when it promotes muscle building and it sucks when it promotes fat storage. The role of insulin in the body is to lower blood sugar levels when they get too high.

When you eat any sort of food it is broken down into its simplest form glucose (sugar) and released into your bloodstream. This release of sugar causes your blood sugar to rise above normal levels. Your pancreas then releases Insulin. Insulin lowers blood sugar levels by putting the glucose into muscle and liver cells. Insulin carries amino acids into the muscles promoting protein synthesis (muscle building) and preventing protein breakdown (muscle loss). Your muscles and liver has a limited storage capacity and once they reach capacity insulin has to carry the remaining glucose somewhere else. YOU GUESSED IT YOUR FAT CELLS!! SO AS I MENTIONED EARLIER INSULIN CAN ALSO LEAD TO FAT STORAGE. So as I mentioned earlier, insulin is a double-edged sword and you must learn to balance your insulin levels to maximize the benefits of muscle building and to minimize the af­fect of fat storage. You can control insulin levels by what you eat.

Different foods can cause higher insulin release than others: ·Carbs- When eaten alone carbohydrates cause the largest insulin release because they are converted directly into sugar by the body – carbs are your body’s primary energy source and they are easily converted to sugar (glucose)50g of carbs is equal to 50g of sugar entering the bloodstream. This sudden flow of sugar into the bloodstream causes a huge rise in blood sugar levels, which inevitably will cause a MASSIVE RELEASE OF INSULIN. ·Protein- When eaten alone Protein causes a smaller insulin release than carbohydrates……. only about half of dietary protein will appear in the bloodstream as sugar. The fewer carbs you eat the more likely the protein consumed is converted to glucose. Your liver will convert the amino acids from protein into glucose. If adequate carbs are eaten with the protein, the body will not convert the protein into glucose. Carbs are the body’s primary energy source and it would rather use those amino acids for other purposes when adequate glucose is available. ·Fats- Only a very small percentage of fat will appear in the bloodstream as glucose. Fat has almost no blood sugar increasing affect at all.

When fat is digested it is primarily broken down into glycerol and free fatty acid chains (FFA). Your liver converts the glycerol into glucose. There are really only a few hours in the day where you can eat a ton of food and create an extremely powerful anabolic environment even with the presence of high insulin levels. Remember, once your liver and muscle storage capacity is full the excess food is stored in your fat cells. So, let me ask you this what times of the day is your muscle and liver glucose storage at their lowest levels? The answer is…….at breakfast and after your workout (cardio or weights)! These are the two main times in the day where your body will take full advantage of the anabolic effects of high insulin with a slimmest possibility of fat storage. Hormone #2: Glucagon Glucagon is a hormone that has a role that is parallel to insulin. Again, Insulin’s function is to lower blood sugar levels and glucagon role is to raise low blood sugar levels. Glucagon released from the pancreas comes to the save you when your blood sugar levels are low. Like insulin, glucagon can be your best friend or your worst foe.

Insulin promotes muscle building and fat storage, while glucagon promotes muscle break­down and fat burning. If blood sugar levels are too low (if you have not eaten for more than 3-4 hours) it mobilizes stored glycogen from the liver and releases glucose for energy. It then begins to help release stored fat into the bloodstream also to be used for energy. However, for very low blood sugar levels such as when you have not eaten for 4-5 hours (during sleep) glucagon plays a role in the breakdown of hard gained muscle for fuel. During fat loss diets, el­evated glucagon levels are important because it causes the burning of stored fat for fuel. Hormone #3: IGF-1 IGF-1 isn't a top-secret chemical, nor is it a dangerous steroid. IGF1 is actually a natural molecular structure similar to insulin. IGF-1 is the abbreviation for Insulin-Like Growth Factor 1. IGF-1 or Insulin-like Growth Factor 1 plays a vital role in childhood growth and stimulates anabolic effects (muscle building) in adults. There are 70 inter-connected amino acids that make up a single chain of IGF-1.

IGF-1 is a hormone that is produced when the liver is stimulated by human growth hormone. When levels of HGH rise in the blood, the liver responds by producing more IGF-1. These higher "bursts" spur growth and regeneration by the body's cells, especially in muscle cells. Increases in IGF-1 levels have shown positive effects on increases in muscle strength, size, and efficiency. When you do not have enough IGF-1 in your body, whether caused by disease, malnutrition or a hormone imbalance, your growth can be stunted. The primary purpose of IGF-1 is to stimulate cell growth. Every cell in the human body can be affected by IGF-1, but cells in muscle, cartilage, bone, liver, kidney, skin tissue, lungs, and nerves tend to be most positively affected. Several scientific tests have been conducted to determine the benefits of IGF-1 and thus have prompted companies to seek approval from the Federal Drug and Administration for substances that can increase the body's IGF-1 levels. IGF-1 can also stimulate a decrease in body fat, an increase in lean muscle mass, improved skin tone and restful sleep.

IGF-1 has also been documented to increase the rate and extent of muscle repair after injuries or strains. Not only do muscles recover more quickly, they also tend to return stronger and healthier than ever when levels of IGF-1 in the bloodstream are at their highest. Many believe that (IGF-1) is the key factor in muscle growth. It is released from the liver during times of high insulin and high GH (growth hormone) levels. I will repeat, to stimulate the production if IGF-1, GH levels and insulin must be high simultaneously. This is the problematic part because when insulin levels are high, GH is normally kept low. This is another reason why insulin levels must be consistently controlled. Insulin levels must be raised at specific times to promote enhanced growth and IGF-1 production. For example, to make IGF-1 work for you after a hard workout of 45 minutes your GH levels will be very high so If you then eat a high carb/high protein meal, you will cause a rise in insulin levels, which will cause the release of IGF-1. IGF-1 is not released during times of low insulin levels.

Low insulin and low IGF-1 levels are the primary reasons it is difficult to gain muscle on low-carb diets. It should be noted to that low pro­tein intake also causes a decrease in IGF-1 levels. Hormone #4: Cortisol Cortisol is the most catabolic hormone in your body and is released at times of mental and physical stress. It is involved in the breakdown of muscle for energy and encourages the storage of fat. Cortisol converts amino acids to carbohydrates and prevents protein synthesis (muscle building). In fact Cortisol may be the very reason why your muscle building efforts have failed thus far!! FOLLOW THESE TIPS TO MINIMIZE CORTISOL LEVELS IN YOUR BODY: Get at least 8 hours of sleep a night. Your body needs sufficient rest or cortisol levels will elevate. Keep your workouts to a 45 minute max excluding warm-up time. Working out longer than this will cause Cortisol levels in the body to skyrocket!! I SUGGEST KEEPING YOUR WORKOUTS TO 30 MINUTES!! High set workouts with short rest periods and training too frequently will drive up cortisol levels.

Training more than two days in a row, especially if you are a hard gainer, increases cortisol levels considerably. Also, it’s a good idea to take a week off from all types of training every couple of months…..long periods of training without recovery weeks can drive up levels of cortisol in the body. Decrease levels of personal, mental and physical stress. LEARN how to deal with daily stress. Learn how to keep your problems in perspective and FOR EVERY STRESSFUL EVENT THAT OCCURS TO YOU A PARTICULAR DAY TREAT YOURSELF TO A TIME OF RELAXATION. Stressing yourself out has shown to increase cortisol levels and inhibit muscle growth. Severe caloric restriction has been shown to increase cortisol levels. This is why extreme dieting and cutting phases where your calories are limited drastically for longer than 3 days results in a increase of cortisol. This is the main reason for muscle tissue loss during periods of dieting. A diet lacking essential micro-nutrients and macro nutrients may increase cortisol lev­els. Take a high quality multivitamin supplement to keep down cortisol levels. Cortisol levels have been shown to increase as we age. I suppose this is why a younger person can work out harder and longer in the weight room.

Therefore I suggest whether you are 60 or 25 keep your workouts max 45 minutes but stay around the 30 minute mark!! Hormone#5: Testosterone Probably the most well known hormone its primary role is muscle growth. It also helps to burn fat and establish your sexual identity. Testosterone causes muscle growth by directly stimulating protein synthesis. Women also produce testosterone but in much smaller amounts than men do which explains why men are naturally more muscular. Fortunately, to some extent, testosterone levels can be controlled by the our diet and exercise levels. In order to support optimal testosterone levels your diet must be balanced and consist of plenty amounts of the B vitamins, vitamin C, zinc and manganese. When trying to gain muscle mass, a high-fat intake is necessary to stimulate maximum testosterone production. The fat provides cholesterol, which is needed for testosterone synthesis. Heavy resistance training and short rest periods stimulate the production of higher than normal testosterone levels. Tips to naturally increase Testosterone levels The higher your stress level the lower your T. Intense training causes an increase in T but then it will drop. T will stay low for a day or two before rising again which is another reason for hard gainers to train every second day.

Alcohol decreases T…… I know its sucks!! Diets high in protein, cholesterol, fat, and saturated fat will increase T. Sex, masturbation and erotic stimuli will cause an increase in T. Painkillers such as aspirin, marijuana, codeine will decrease T. Hormone #6: Growth Hormone (GH) Growth hormone promotes muscle building and fat loss. It works with testosterone to build muscle. GH helps to regenerate/strengthen our bones and connective tissue crucial to support increased muscle size and strength. GH appears to affect every organ in the body, has been shown to support protein synthesis, a positive nitrogen balance, increased amino acid uptake, lipolysis (fat breakdown), stimulate cartilage growth, and enhance immune cell function. It is released in response to low blood sugar levels caused by dieting, exer­cise or sleep. Once released, it promotes growth by increasing protein synthesis, and causing the re­lease of IGF-1. It also promotes fat burning by moving stored fat into the bloodstream to be used as energy. This is its primary function and because of this fat burning effect, GH reduces the amount of protein that is used for fuel, so high GH levels will protect against muscle breakdown and loss.

How to naturally increase GH levels Eat low glycemic carbohydrates to keep blood sugars low, especially before exercise and sleep. Go to bed on an empty stomach. Meals heavy in carbohydrates produce insulin, which can help store fat. When insulin is being released it means no GH release. Get a good night’s sleep on a regular basis. Large amounts of GH are released during the first 30-70 minutes of sleep and take naps when needed. High intensity weight training increases GH levels. While performing your sets, keep tension as high as possible on muscles without rest to optimize GH levels. Eat a balanced diet with frequent meals 6 times daily. This will stabilize blood sugar levels. Meals should consist of Carbs/protein/fat. Train using compound movements, for example, squats, dead lifts and bench-press. Reduce your intake of sugar. Excessive sugar intake can block activity of GH and stop the burning of fat for fuel. How Our Bodies Turn Food Into Energy Classes & Events How Our Bodies Turn Food Into Energy All parts of the body (muscles, brain, heart, and liver) need energy to work. This energy comes from the food we eat.

Our bodies digest the food we eat by mixing it with fluids (acids and enzymes) in the stomach. When the stomach digests food, the carbohydrate (sugars and starches) in the food breaks down into another type of sugar, called glucose. The stomach and small intestines absorb the glucose and then release it into the bloodstream. Once in the bloodstream, glucose can be used immediately for energy or stored in our bodies, to be used later. However, our bodies need insulin in order to use or store glucose for energy. Without insulin, glucose stays in the bloodstream, keeping blood sugar levels high. How the Body Makes Insulin Insulin is a hormone made by beta cells in the pancreas. Beta cells are very sensitive to the amount of glucose in the bloodstream. Normally beta cells check the blood's glucose level every few seconds and sense when they need to speed up or slow down the amount of insulin they're making and releasing. When someone eats something high in carbohydrates, like a piece of bread, the glucose level in the blood rises and the beta cells trigger the pancreas to release more insulin into the bloodstream.

See Illustration: How Insulin Works Insulin Opens Cell Doors When insulin is released from the pancreas, it travels through the bloodstream to the body's cells and tells the cell doors to open up to let the glucose in. Once inside, the cells convert glucose into energy to use right then or store it to use later. As glucose moves from the bloodstream into the cells, blood sugar levels start to drop. The beta cells in the pancreas can tell this is happening, so they slow down the amount of insulin they're making. At the same time, the pancreas slows down the amount of insulin that it's releasing into the bloodstream. When this happens, the amount of glucose going into the cells also slows down. Balancing Insulin and Blood Sugar for Energy The rise and fall in insulin and blood sugar happens many times during the day and night. The amount of glucose and insulin in our bloodstream depends on when we eat and how much. When the body is working as it should, it can keep blood sugar at a normal level, which is between 70 and 120 milligrams per deciliter. However, even in people without diabetes, blood sugar levels can go up as high as 180 during or right after a meal.

Within two hours after eating, blood sugar levels should drop to under 140. After several hours without eating, blood sugar can drop as low as 70. Using glucose for energy and keeping it balanced with just the right amount of insulin — not too much and not too little — is the way our bodies maintain the energy needed to stay alive, work, play, and function even as we sleep. Insulin Helps Our Bodies Store Extra Glucose Insulin helps our cells convert glucose into energy, and it helps our bodies store extra glucose for use later. For example, if you eat a large meal and your body doesn't need that much glucose right away, insulin will help your body store it to convert to energy later. Insulin does this by turning the extra food into larger packages of glucose called glycogen. Glycogen is stored in the liver and muscles. Insulin also helps our bodies store fat and protein. Almost all body cells need protein to work and grow. The body needs fat to protect nerves and make several important hormones. Fat can also be used by the body as an energy source.

How Diabetes Changes the Way This Works With diabetes, the body has stopped making insulin, has slowed down the amount of insulin it's making, or is no longer able to use its own insulin very well. When this happens, it can lead to several things. For example, glucose cannot enter the cells where it's needed, so the amount of glucose in the bloodstream continues to rise. This is called hyperglycemia (high blood sugar). When blood sugar levels reach 180 or higher, the kidneys try to get rid of the extra sugar through the urine. This makes a person urinate more than usual. It also makes a person feel thirstier because of the water he or she is losing by urinating so much. When a person loses sugar in the urine, it's the same as losing energy because the sugar isn't available for the cells to use or store. When this happens, a person might feel tired, lose weight, and feel hungry all the time. Other problems caused by high blood sugar include blurry vision and skin infections or injuries that don't heal. Women might have vaginal yeast infections more often. When the body doesn't have enough insulin to help convert sugar into energy, it often starts burning body fat instead.

This sounds like it might work well, but burning too much fat for energy produces a byproduct called ketones. High levels of ketones can lead to a condition called diabetic ketoacidosis (DKA), which can be life threatening if not treated quickly. DKA is more common in type 1 diabetes because the body has stopped making insulin. Keep Blood Sugar Levels Under Control For a person with diabetes, the main focus of treatment is to control the amount of glucose in the body so that blood sugar levels stay as close to normal as possible. People with type 1 diabetes need insulin shots as part of their care plan to control their blood sugar levels. Some people with type 2 diabetes can control their blood sugar levels with a healthy diet and exercise. However, many people with type 2 diabetes will need to include diabetes pills, insulin shots, or both in their diabetes care plans. People with either type 1 or type 2 diabetes need to pay close attention to how blood sugar levels change at various times throughout the day in order to keep them as close to normal as possible. When blood sugar levels are close to normal, it means the body is getting the energy it needs to work, play, heal, and stay healthy.

Clinical review by David McCulloch, MD Group Health Blood Sugar Regulation - Biology Encyclopedia - cells, body, function, human, system, life, hormone, used, structure Blood Sugar Regulation - Biology Encyclopedia Blood Sugar Regulation Photo by: Andrew Gentry Most cells in the human body use the sugar called glucose as their major source of energy. Glucose molecules are broken down within cells in order to produce adenosine triphosphate (ATP) molecules, energy-rich molecules that power numerous cellular processes. Glucose molecules are delivered to cells by the circulating blood and therefore, to ensure a constant supply of glucose to cells, it is essential that blood glucose levels be maintained at relatively constant levels. Level constancy is accomplished primarily through negative feedback systems, which ensure that blood glucose concentration is maintained within the normal range of 70 to 110 milligrams (0.0024 to 0.0038 ounces) of glucose per deciliter (approximately one-fifth of a pint) of blood. Negative feedback systems are processes that sense changes in the body and activate mechanisms that reverse the changes in order to restore conditions to their normal levels. Negative feedback systems are critically important in homeostasis, the maintenance of relatively constant internal conditions.

Disruptions in homeostasis lead to potentially life-threatening situations. The maintenance of relatively constant blood glucose levels is essential for the health of cells and thus the health of the entire body. Major factors that can increase blood glucose levels include glucose absorption by the small intestine (after ingesting a meal) and the production of new glucose molecules by liver cells. Major factors that can decrease blood The homeostatic regulation of glucose concentrations. glucose levels include the transport of glucose into cells (for use as a source of energy or to be stored for future use) and the loss of glucose in urine (an abnormal event that occurs in diabetes mellitus). Insulin and Glucagon In a healthy person, blood glucose levels are restored to normal levels primarily through the actions of two pancreatic hormones , namely insulin and glucagon. If blood glucose levels rise (for example, during the fed or absorptive state, when a meal is digested and the nutrient molecules are being absorbed and used), the beta cells of the pancreas respond by secreting insulin.

Insulin has several notable effects: (1) it stimulates most body cells to increase their rate of glucose uptake (transport) from the blood; (2) it increases the cellular rate of glucose utilization as an energy source; (3) it accelerates the formation of glycogen from glucose in liver and skeletal muscle cells; and (4) it stimulates fat synthesis (from glucose) in liver cells and adipose (fat) tissue. These effects collectively cause a decrease in blood glucose levels back to normal levels.

If blood glucose levels fall below normal levels (for instance, during the post-absorptive or fasting state, when nutrients from a recently digested meal are no longer circulating in the blood, or during starvation), insulin secretion is inhibited and, at the same time, the alpha cells of the pancreas respond by secreting glucagon, a hormone that has several important effects: (1) it accelerates the breakdown of glycogen to glucose in liver and skeletal muscle cells; (2) it increases the breakdown of fats to fatty acids and glycerol in adipose tissue and, consequently, the release of these substances into the blood (which cells can thus use for energy); and (3) it stimulates liver cells to increase glucose synthesis (from glycerol absorbed from the blood) and glucose release into the blood. These effects collectively cause an increase in blood glucose levels back to normal levels. In addition to insulin and glucagon, there are several other hormones that can influence blood glucose levels. The most important ones are epinephrine, cortisol, and growth hormone, all of which can increase blood glucose levels. Diseases and Blood Sugar Regulation Glucose levels above or below the normal range are indicative of the presence of disease states.

For example, elevated glucose levels are present in diabetes mellitus, Cushing's syndrome, liver disease, and hyperthyroidism, while decreased glucose levels are present in Addison's disease, hyperinsulinism, and hypothyroidism. The most prevalent of these diseases is diabetes mellitus. There are two types of this disease: Type I (insulin-dependent or juvenile-onset) diabetes mellitus, and Type II (noninsulin-dependent or maturity-onset) diabetes mellitus. In Type I diabetes, pancreatic beta cells are destroyed by an erroneous attack by the body's own immune system, and thus insulin secretion is reduced to negligible levels. In Type II diabetes, insulin secretion is not reduced; however, there is a reduced sensitivity of target cells to insulin, a phenomenon known as insulin resistance. SEE ALSO Pancreas and insulin - myDr.com.au Pancreas and insulin Pancreas and insulin Your pancreas is one of the organs of your digestive system. It lies in your abdomen, behind your stomach. It is a long thin structure with 2 main functions: producing digestive enzymes to break down food; and producing the hormones insulin and glucagon to control sugar levels in your body.

Production of digestive enzymes The pancreas produces secretions necessary for you to digest food. The enzymes in these secretions allow your body to digest protein, fat and starch from your food. The enzymes are produced in the acinar cells which make up most of the pancreas. From the acinar cells the enzymes flow down various channels into the pancreatic duct and then out into the duodenum. The secretions are alkaline to balance the acidic juices and partially digested food coming into the duodenum from the stomach. Production of hormones to control blood sugar levels A small proportion (1-2 per cent) of the pancreas is made up of other types of cells called islets of Langerhans. These cells sit in tiny groups, like small islands, scattered throughout the tissue of the pancreas. The islets of Langerhans contain alpha cells which secrete glucagon and beta cells which secrete insulin. Insulin and glucagon are hormones that work to regulate the level of sugar (glucose) in the body to keep it within a healthy range. Unlike the acinar cells, the islets of Langerhans do not have ducts and secrete insulin and glucagon directly into the bloodstream.

Depending on what you’ve eaten, how much exercise your muscles are doing, and how active your body cells are, the amount of glucose in your bloodstream and cells varies. These 2 hormones have the job of keeping tight control of the amount of glucose in your blood so that it doesn’t rise or fall outside of healthy limits. How insulin works Insulin is released from the beta cells in your pancreas in response to rising glucose in your bloodstream. After you eat a meal, any carbohydrates you’ve eaten are broken down into glucose and passed into the bloodstream. The pancreas detects this rise in blood glucose and starts to secrete insulin. Insulin works by improving the uptake of glucose from the blood across cell membranes and into the cells of the body, and so takes glucose out of the bloodstream. Once in the cells, the glucose is used as the energy to fuel the cells doing their different jobs or is stored in the liver or muscle cells as glycogen. This results in the glucose level of the blood dropping, which then triggers the pancreas to switch off the release of insulin. The problem in people with diabetes is that either they don’t produce enough insulin, or the insulin they do produce doesn’t work properly, or their cells don’t respond properly to insulin.

The net result is that glucose isn’t cleared from their bloodstream and they have high blood glucose levels which the body tries to clear by various compensatory methods, such as increased urination. How glucagon works Glucagon has an opposite (antagonistic) effect to insulin. When your blood glucose level falls, for example during exercise when your muscles are using glucose for fuel, your pancreas detects the drop in blood glucose. This prompts the pancreas to slow down the secretion of insulin, but increase the output of glucagon. The role of glucagon is to break down glycogen (the stored form of glucose) in the liver. Then the liver releases glucose into the bloodstream. This results in a rise in the blood glucose level to bring it back to a healthy level, which in turn signals the pancreas to switch off glucagon release. The control of blood glucose levels operates by what is known as a negative feedback mechanism. Here is a summary of the 2 control loops.

When the blood glucose level goes up Blood sugar (glucose) rises; The pancreas detects the rise; The pancreas pumps out insulin into the blood; Insulin helps the uptake of glucose into muscles and other cells; This causes the blood glucose level to fall to its normal set point; and The pancreas detects the fall and switches off insulin production. When the blood glucose level goes down Blood sugar (glucose) drops; The pancreas detects the drop in blood sugar; The pancreas switches on the output of glucagon into the blood; Glucagon signals the liver to break down glycogen into glucose; The liver releases glucose into the bloodstream; Blood glucose goes up to its normal set point; and The pancreas detects the rise in blood sugar and switches off glucagon release. Last Reviewed: 14 September 2009 myDr Endocrine System: Discover the Anatomy and Function of Glands Oxytocin Antidiuretic hormone (ADH) All of the releasing and inhibiting hormones affect the function of the anterior pituitary gland. TRH stimulates the anterior pituitary gland to release thyroid-stimulating hormone.

GHRH and GHIH work to regulate the release of growth hormone—GHRH stimulates growth hormone release, GHIH inhibits its release. GnRH stimulates the release of follicle stimulating hormone and luteinizing hormone while CRH stimulates the release of adrenocorticotropic hormone. The last two hormones—oxytocin and antidiuretic hormone—are produced by the hypothalamus and transported to the posterior pituitary, where they are stored and later released. Pituitary Gland The pituitary gland , also known as the hypophysis, is a small pea-sized lump of tissue connected to the inferior portion of the hypothalamus of the brain. Many blood vessels surround the pituitary gland to carry the hormones it releases throughout the body. Situated in a small depression in the sphenoid bone called the sella turcica, the pituitary gland is actually made of 2 completely separate structures: the posterior and anterior pituitary glands. Posterior Pituitary: The posterior pituitary gland is actually not glandular tissue at all, but nervous tissue instead.

The posterior pituitary is a small extension of the hypothalamus through which the axons of some of the neurosecretory cells of the hypothalamus extend. These neurosecretory cells create 2 hormones in the hypothalamus that are stored and released by the posterior pituitary: Oxytocin triggers uterine contractions during childbirth and the release of milk during breastfeeding. Antidiuretic hormone (ADH) prevents water loss in the body by increasing the re-uptake of water in the kidneys and reducing blood flow to sweat glands. Anterior Pituitary: The anterior pituitary gland is the true glandular part of the pituitary gland. The function of the anterior pituitary gland is controlled by the releasing and inhibiting hormones of the hypothalamus. The anterior pituitary produces 6 important hormones: Thyroid stimulating hormone (TSH), as its name suggests, is a tropic hormone responsible for the stimulation of the thyroid gland. Adrenocorticotropic hormone (ACTH) stimulates the adrenal cortex, the outer part of the adrenal gland, to produce its hormones.

Follicle stimulating hormone (FSH) stimulates the follicle cells of the gonads to produce gametes—ova in females and sperm in males. Luteinizing hormone (LH) stimulates the gonads to produce the sex hormones—estrogens in females and testosterone in males. Human growth hormone (HGH) affects many target cells throughout the body by stimulating their growth, repair, and reproduction. Prolactin (PRL) has many effects on the body, chief of which is that it stimulates the mammary glands of the breast to produce milk. Pineal Gland The pineal gland is a small pinecone-shaped mass of glandular tissue found just posterior to the thalamus of the brain. The pineal gland produces the hormone melatonin that helps to regulate the human sleep-wake cycle known as the circadian rhythm. The activity of the pineal gland is inhibited by stimulation from the photoreceptors of the retina. This light sensitivity causes melatonin to be produced only in low light or darkness. Increased melatonin production causes humans to feel drowsy at nighttime when the pineal gland is active.

Thyroid Gland The thyroid gland is a butterfly-shaped gland located at the base of the neck and wrapped around the lateral sides of the trachea. The thyroid gland produces 3 major hormones: Calcitonin Triiodothyronine (T3) Thyroxine (T4) Calcitonin is released when calcium ion levels in the blood rise above a certain set point. Calcitonin functions to reduce the concentration of calcium ions in the blood by aiding the absorption of calcium into the matrix of bones. The hormones T3 and T4 work together to regulate the body’s metabolic rate. Increased levels of T3 and T4 lead to increased cellular activity and energy usage in the body. Parathyroid Glands The parathyroid glands are 4 small masses of glandular tissue found on the posterior side of the thyroid gland. The parathyroid glands produce the hormone parathyroid hormone (PTH), which is involved in calcium ion homeostasis. PTH is released from the parathyroid glands when calcium ion levels in the blood drop below a set point. PTH stimulates the osteoclasts to break down the calcium containing bone matrix to release free calcium ions into the bloodstream.

PTH also triggers the kidneys to return calcium ions filtered out of the blood back to the bloodstream so that it is conserved. Adrenal Glands The adrenal glands are a pair of roughly triangular glands found immediately superior to the kidneys. The adrenal glands are each made of 2 distinct layers, each with their own unique functions: the outer adrenal cortex and inner adrenal medulla. Adrenal cortex: The adrenal cortex produces many cortical hormones in 3 classes: glucocorticoids, mineralocorticoids, and androgens. Glucocorticoids have many diverse functions, including the breakdown of proteins and lipids to produce glucose. Glucocorticoids also function to reduce inflammation and immune response. Mineralocorticoids, as their name suggests, are a group of hormones that help to regulate the concentration of mineral ions in the body. Androgens, such as testosterone, are produced at low levels in the adrenal cortex to regulate the growth and activity of cells that are receptive to male hormones. In adult males, the amount of androgens produced by the testes is many times greater than the amount produced by the adrenal cortex, leading to the appearance of male secondary sex characteristics.

Adrenal medulla: The adrenal medulla produces the hormones epinephrine and norepinephrine under stimulation by the sympathetic division of the autonomic nervous system. Both of these hormones help to increase the flow of blood to the brain and muscles to improve the “fight-or-flight” response to stress. These hormones also work to increase heart rate, breathing rate, and blood pressure while decreasing the flow of blood to and function of organs that are not involved in responding to emergencies. Pancreas The pancreas is a large gland located in the abdominal cavity just inferior and posterior to the stomach . The pancreas is considered to be a heterocrine gland as it contains both endocrine and exocrine tissue. The endocrine cells of the pancreas make up just about 1% of the total mass of the pancreas and are found in small groups throughout the pancreas called islets of Langerhans. Within these islets are 2 types of cells—alpha and beta cells. The alpha cells produce the hormone glucagon, which is responsible for raising blood glucose levels. Glucagon triggers muscle and liver cells to break down the polysaccharide glycogen to release glucose into the bloodstream.

The beta cells produce the hormone insulin, which is responsible for lowering blood glucose levels after a meal. Insulin triggers the absorption of glucose from the blood into cells, where it is added to glycogen molecules for storage. Gonads The gonads—ovaries in females and testes in males—are responsible for producing the sex hormones of the body. These sex hormones determine the secondary sex characteristics of adult females and adult males. Testes: The testes are a pair of ellipsoid organs found in the scrotum of males that produce the androgen testosterone in males after the start of puberty. Testosterone has effects on many parts of the body, including the muscles, bones, sex organs, and hair follicles. This hormone causes growth and increases in strength of the bones and muscles, including the accelerated growth of long bones during adolescence. During puberty, testosterone controls the growth and development of the sex organs and body hair of males, including pubic, chest, and facial hair. In men who have inherited genes for baldness testosterone triggers the onset of androgenic alopecia, commonly known as male pattern baldness. Ovaries: The ovaries are a pair of almond-shaped glands located in the pelvic body cavity lateral and superior to the uterus in females.

The ovaries produce the female sex hormones progesterone and estrogens. Progesterone is most active in females during ovulation and pregnancy where it maintains appropriate conditions in the human body to support a developing fetus. Estrogens are a group of related hormones that function as the primary female sex hormones. The release of estrogen during puberty triggers the development of female secondary sex characteristics such as uterine development, breast development, and the growth of pubic hair. Estrogen also triggers the increased growth of bones during adolescence that lead to adult height and proportions. Thymus The thymus is a soft, triangular-shaped organ found in the chest posterior to the sternum. The thymus produces hormones called thymosins that help to train and develop T-lymphocytes during fetal development and childhood. The T-lymphocytes produced in the thymus go on to protect the body from pathogens throughout a person’s entire life. The thymus becomes inactive during puberty and is slowly replaced by adipose tissue throughout a person’s life. Other Hormone Producing Organs In addition to the glands of the endocrine system, many other non-glandular organs and tissues in the body produce hormones as well.

Heart: The cardiac muscle tissue of the heart is capable of producing the hormone atrial natriuretic peptide (ANP) in response to high blood pressure levels. ANP works to reduce blood pressure by triggering vasodilation to provide more space for the blood to travel through. ANP also reduces blood volume and pressure by causing water and salt to be excreted out of the blood by the kidneys. Kidneys: The kidneys produce the hormone erythropoietin (EPO) in response to low levels of oxygen in the blood. EPO released by the kidneys travels to the red bone marrow where it stimulates an increased production of red blood cells. The number of red blood cells increases the oxygen carrying capacity of the blood, eventually ending the production of EPO. Digestive System: The hormones cholecystokinin (CCK), secretin, and gastrin are all produced by the organs of the gastrointestinal tract. CCK, secretin, and gastrin all help to regulate the secretion of pancreatic juice, bile, and gastric juice in response to the presence of food in the stomach. CCK is also instrumental in the sensation of satiety or “fullness” after eating a meal.

Adipose: Adipose tissue produces the hormone leptin that is involved in the management of appetite and energy usage by the body. Leptin is produced at levels relative to the amount of adipose tissue in the body, allowing the brain to monitor the body’s energy storage condition. When the body contains a sufficient level of adipose for energy storage, the level of leptin in the blood tells the brain that the body is not starving and may work normally. If the level of adipose or leptin decreases below a certain threshold, the body enters starvation mode and attempts to conserve energy through increased hunger and food intake and decreased energy usage. Adipose tissue also produces very low levels of estrogens in both men and women. In obese people the large volume of adipose tissue may lead to abnormal estrogen levels. Placenta: In pregnant women, the placenta produces several hormones that help to maintain pregnancy. Progesterone is produced to relax the uterus, protect the fetus from the mother’s immune system , and prevent premature delivery of the fetus. Human chorionic gonadotropin (HCG) assists progesterone by signaling the ovaries to maintain the production of estrogen and progesterone throughout pregnancy.

Local Hormones: Prostaglandins and leukotrienes are produced by every tissue in the body (except for blood tissue) in response to damaging stimuli. These two hormones mainly affect the cells that are local to the source of damage, leaving the rest of the body free to function normally. Prostaglandins cause swelling, inflammation, increased pain sensitivity, and increased local body temperature to help block damaged regions of the body from infection or further damage. They act as the body’s natural bandages to keep pathogens out and swell around damaged joints like a natural cast to limit movement. Leukotrienes help the body heal after prostaglandins have taken effect by reducing inflammation while helping white blood cells to move into the region to clean up pathogens and damaged tissues. Physiology of the Endocrine System Endocrine System vs. Nervous System Function The endocrine system works alongside of the nervous system to form the control systems of the body. The nervous system provides a very fast and narrowly targeted system to turn on specific glands and muscles throughout the body. The endocrine system, on the other hand, is much slower acting, but has very widespread, long lasting, and powerful effects.

Hormones are distributed by glands through the bloodstream to the entire body, affecting any cell with a receptor for a particular hormone. Most hormones affect cells in several organs or throughout the entire body, leading to many diverse and powerful responses. Hormone Properties Once hormones have been produced by glands, they are distributed through the body via the bloodstream. As hormones travel through the body, they pass through cells or along the plasma membranes of cells until they encounter a receptor for that particular hormone. Hormones can only affect target cells that have the appropriate receptors. This property of hormones is known as specificity. Hormone specificity explains how each hormone can have specific effects in widespread parts of the body. Many hormones produced by the endocrine system are classified as tropic hormones. A tropic hormone is a hormone that is able to trigger the release of another hormone in another gland. Tropic hormones provide a pathway of control for hormone production as well as a way for glands to be controlled in distant regions of the body. Many of the hormones produced by the pituitary gland, such as TSH, ACTH, and FSH are tropic hormones. Hormonal Regulation The levels of hormones in the body can be regulated by several factors.

The nervous system can control hormone levels through the action of the hypothalamus and its releasing and inhibiting hormones. For example, TRH produced by the hypothalamus stimulates the anterior pituitary to produce TSH. Tropic hormones provide another level of control for the release of hormones. For example, TSH is a tropic hormone that stimulates the thyroid gland to produce T3 and T4. Nutrition can also control the levels of hormones in the body. For example, the thyroid hormones T3 and T4 require 3 or 4 iodine atoms, respectively, to be produced. In people lacking iodine in their diet, they will fail to produce sufficient levels of thyroid hormones to maintain a healthy metabolic rate. Finally, the number of receptors present in cells can be varied by cells in response to hormones. Cells that are exposed to high levels of hormones for extended periods of time can begin to reduce the number of receptors that they produce, leading to reduced hormonal control of the cell. Classes of Hormones Hormones are classified into 2 categories depending on their chemical make-up and solubility: water-soluble and lipid-soluble hormones.

Each of these classes of hormones has specific mechanisms for their function that dictate how they affect their target cells. Water-soluble hormones: Water-soluble hormones include the peptide and amino-acid hormones such as insulin, epinephrine, HGH, and oxytocin. As their name indicates, these hormones are soluble in water. Water-soluble hormones are unable to pass through the phospholipid bilayer of the plasma membrane and are therefore dependent upon receptor molecules on the surface of cells. When a water-soluble hormone binds to a receptor molecule on the surface of a cell, it triggers a reaction inside of the cell. This reaction may change a factor inside of the cell such as the permeability of the membrane or the activation of another molecule. A common reaction is to cause molecules of cyclic adenosine monophosphate (cAMP) to be synthesized from adenosine triphosphate (ATP) present in the cell. cAMP acts as a second messenger within the cell where it binds to a second receptor to change the function of the cell’s physiology.

Lipid-soluble hormones: Lipid-soluble hormones include the steroid hormones such as testosterone, estrogens, glucocorticoids, and mineralocorticoids. Because they are soluble in lipids, these hormones are able to pass directly through the phospholipid bilayer of the plasma membrane and bind directly to receptors inside the cell nucleus. Lipid-soluble hormones are able to directly control the function of a cell from these receptors, often triggering the transcription of particular genes in the DNA to produce "messenger RNAs (mRNAs)" that are used to make proteins that affect the cell’s growth and function. Prepared by Tim Taylor, Anatomy and Physiology Instructor

Question: Which hormone controls the supply of sugar from the blood to the muscles?
Answer: INSULIN