Glycemia is the concentration of glucose in the blood. It is usually expressed in milligrams per deciliter (mg/dl). It is one of the most important controlled variables in the internal milieu of animals (homeostasis), as it was first proposed by French physiologist Claude Bernard (1813-1878). Glucose (Glc), a monosaccharide, is one of the most important carbohydrates. ... Red blood cells (erythrocytes) are present in the blood and help carry oxygen to the rest of the cells in the body Blood is a circulating tissue composed of fluid plasma and cells (red blood cells, white blood cells, platelets). ... Homeostasis is the property of an open system, especially living organisms, to regulate its internal environment to maintain a stable, constant condition, by means of multiple dynamic equilibrium adjustments, controlled by interrelated regulation mechanisms. ... Physiology (in Greek physis = nature and logos = word) is the study of the mechanical, physical, and biochemical functions of living organisms. ... Claude Bernard Claude Bernard (July 12, 1813 - February 10, 1878) was a French physiologist. ...

Physiological regulation

Glycemia is controlled by several physiological processes. It tends to fluctuate to higher levels after meals, due to the gastric and intestinal absorption of carbohydrates of low molecular weight present in the diet or broken down from other kinds of foodstuffs, such as starches (polysaccharides); and to lower levels with usage by cell metabolism, particularly after stress, temperature regulation and physical exhertion. Another input to glycemia levels is neoglucogenesis, whereby glycogen stored in the liver and skeletal muscles, or aminoacids and lipids are converted to glucose via several metabolic chains. Excess glucose is converted to glycogen or to triglycerides for energy storage. Physiology (in Greek physis = nature and logos = word) is the study of the mechanical, physical, and biochemical functions of living organisms. ... The stomach (Gaster) In anatomy, the stomach (in ancient Greek στόμαχος) is an organ in the alimentary canal used to digest food. ... The intestine is the portion of the alimentary canal extending from the stomach to the anus and, in humans and other mammals, consists of two segments, the small intestine and the large intestine. ... Absorption has a number of meanings: In physics, absorption is a process in which particles of some sort encounter another material and are taken up by or even disappear in it. ... Carbohydrates are chemical compounds that contain oxygen, hydrogen, and carbon atoms. ... The molecular mass of a substance (less accurately called molecular weight and abbreviated as MW) is the mass of one molecule of that substance, relative to the unified atomic mass unit u (equal to 1/12 the mass of one atom of carbon-12). ... Diet may mean: In nutrition: Diet (nutrition), the sum of the food consumed by an organism or group. ... Food from plant sources Food is any substance normally eaten or drunk by living organisms. ... Starch is a complex carbohydrate which is insoluble in water. ... Polysaccharides (sometimes called glycans) are relatively complex carbohydrates. ... A few of the metabolic pathways in a cell. ... Stress (roughly the opposite of relaxation) is a medical term for a wide range of strong external stimuli, both physiological and psychological, which can cause a physiological response called the general adaptation syndrome, first described in 1936 by Hans Selye in the journal Nature. ... Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when temperature surrounding is very different. ... Marines doing push-ups. ... Gluconeogenesis, ultimately, is the generation of glucose from noncarbohydrate sources like lactate, glycerol, and amino acids. ... Electron micrograph of a section of a liver cell showing glycogen deposits as accumulations of electron dense particles (arrows). ... The liver is one of the largest internal organs of the human body. ... A top-down view of skeletal muscle Skeletal muscle is a type of striated muscle, attached to the skeleton. ... In chemistry, an amino acid is any molecule that contains both amino and carboxylic acid functional groups. ... Figure 1: Structure of a Lipid. ... Triglycerides (also known as triacylglycerols or triacylglycerides) are glycerides in which the glycerol is esterified with three fatty acids. ...

Glucose is the most important source of metabolic energy for the majority of cells, particularly for some cells (e.g., neurons and erythrocytes) which are almost totally dependent on it. The brain, requires a fairly stable glycemia in order to function normally. Concentrations of less than about 30 mg/dL or greater than about 300 mg/dL can produce confusion, unconsciousness and convulsions. Cells in culture, stained for keratin (red) and DNA (green) The cell is the structural and functional unit of all living organisms, and are sometimes called the building blocks of life. ... Drawing by Santiago Ramón y Cajal of cells in the pigeon cerebellum. ... Human red blood cells Red blood cells are the most common type of blood cell and are the vertebrate bodys principal means of delivering oxygen to body tissues via the blood. ... Comparative brain sizes In the anatomy of animals, the brain, or encephalon (Greek for in the head), is the higher, supervisory center of the nervous system. ... Confusion can have the following meanings: Unclarity, e. ... Unconsciousness is the absence of consciousness. ... This article is about the medical condition. ...

Several hormones are involved in the regulation of glucose metabolism, such as insulin, glucagon (secreted by the pancreas), adrenalin (secreted by the adrenal glands), glucocorticoids and steroid hormones (secreted by the gonads and adrenal glands). Hormone is also the NATO reporting name for the Soviet/Russian Kamov Ka-25 military helicopter. ... The structure of insulin Red: carbon; green: oxygen; blue: nitrogen; pink: sulfur. ... Glucagon ball and stick model Glucagon is a 29 amino acid polypeptide acting as an important hormone in carbohydrate metabolism. ... The pancreas is an organ that serves two functions: exocrine - it produces pancreatic juice containing digestive enzymes. ... Epinephrine (INN) or adrenaline (BAN) is a hormone and a neurotransmitter. ... In mammals, the adrenal glands (also known as suprarenal glands or colloquially as kidney hats) are the triangle-shaped endocrine glands that sit atop the kidneys. ... The name glucocorticoid derives from early observations that these hormones were involved in glucose metabolism. ... Steroid hormones are steroids which act as hormones. ... A sex organ, or primary sexual characteristic, narrowly defined, is any of those parts of the body (which are not always bodily organs according to the strict definition) which are involved in sexual reproduction and constitute the reproductive system in an complex organism; namely: Male: penis (notably the glans penis...

Measurement

For clinical evaluation purposes, there are two ways of measuring glycemia:

• Fasting glycemia: measured in a blood sample taken after 8 hours of complete fasting;
• Blood glucose tolerance test (OGTT): measured in several blood samples taken at intervals following a given glucose load (oral intake of endovenous injection).

In certain conditions, it is recommended that blood glucose monitoring be performed regularly, usually by the patient himself, who is trained to do a digital venipuncture and use a small portable glucometer device to evaluate glycemia levels instantly. Fasting is the act of willingly abstaining from all food and in some cases drink, for a period of time. ... A Glucose Tolerance Test in medical practice is the administration of glucose to determine how quickly it is cleared from the blood. ... Blood glucose monitoring is a way of testing how much glucose is in the blood. ... Venipuncture (also known as phlebotomy or simply bleeding) is the process of obtaining blood from someone, from one of their veins. ... A glucose meter is a medical device for determining the approximate amount of glucose in a drop of blood obtained by pricking the skin with a lancet. ...

Glycemia fluctuates physiologically within a narrow range. Excessively low levels (e.g. a fasting glycemia of 70 mg/dl or below) are classed as hypoglycemia. These may result from poor diet, or as a side effect of diabetes medication. Excessively high levels (e.g. 250 mg/dl or more) are classed as hyperglycemia and are a particular threat to diabetes sufferers. Hypoglycemia is a medical term referring to a pathologic state produced by a lower than normal amount of sugar (glucose) in the blood. ... This article is about the disease that features high blood sugar. ... Hyperglycemia or High Blood Sugar is a condition in which an excessive amount of glucose circulates in the blood plasma. ... This article is about the disease that features high blood sugar. ...

• 70-100 mg/dL: Normal
• 101-125 mg/dL: Impaired fasting glucose
• 126 mg/dL and above: Risk of diabetes

Abnormal values

Many forms of severe stress and trauma, stroke, heart attack, and surgery can temporarily increase glucose levels. Glycemia can also be increased by certain drugs such as antidepressants, corticosteroids, diuretics, estrogens, lithium, phenotiazine, phenytoin and salicilates; or decreased by others, such as acetaminophen, alcohol, steroids, clofibrate, gemfibrozil, etc. Trauma can : A serious and often body-altering physical injury, such as the removal of a limb. ... A stroke or cerebrovascular accident (CVA) occurs when the blood supply to a part of the brain is suddenly interrupted. ... A myocardial infarction occurs when an atherosclerotic plaque slowly builds up in the inner lining of a coronary artery and then suddenly ruptures, totally occluding the artery and preventing blood flow downstream. ... A typical modern surgery operation Surgery (from the Greek cheirourgia meaning hand work) is the medical specialty that treats diseases or injuries by operative manual and instrumental treatment. ... A medication is a licenced drug taken to cure or reduce symptoms of an illness or medical condition. ... An antidepressant is a medication used primarily in the treatment of clinical depression. ... In physiology, corticosteroids are a class of steroid hormones that are produced in the adrenal cortex. ... A diuretic is any drug that tends to increase the flow of urine from the body (diuresis). ... Estrogens (also oestrogens) are a group of steroid compounds that function as the primary female sex hormone. ... General Name, Symbol, Number lithium, Li, 3 Chemical series alkali metals Group, Period, Block 1, 2, s Appearance silvery white/gray Atomic mass 6. ... Phenytoin sodium (marketed as Dilantin® in the USA and as Epanutin® in the UK, by Parke-Davis, now part of Pfizer) is a commonly used antiepileptic. ... Acetaminophen (USAN) or paracetamol (INN), is a popular analgesic and antipyretic drug that is used for the relief of fever, headaches, and other minor aches and pains. ... In general usage, alcohol (from Arabic al-kukhul الكحول, al meaning the and kukhul meaning spirit, the chemical) refers almost always to ethanol, also known as grain alcohol, and often to any beverage that contains ethanol (see alcoholic beverage). ... In chemistry and biology, Steroids are a type of lipid, characterized by a carbon skeleton with four fused rings. ... Gemfibrozil is the generic name for a oral lipid lowering drug. ...

However, the disease most directly associated to chronic increase of glycemia is diabetes mellitus, due to a decrease in the secretion of insulin, excess of its breakdown or decreased capacity of cells to transport it across its membranes (insulin resistance). Diabetes mellitus is a medical disorder characterized by varying or persistent hyperglycemia (elevated blood sugar levels), especially after eating. ... Drawing of a cell membrane A component of every biological cell, the selectively permeable cell membrane (or plasma membrane or plasmalemma) is a thin and structured bilayer of phospholipid and protein molecules that envelopes the cell. ... In medicine, insulin resistance denotes a decompensation of glucose homeostasis where the tissues appear to be less responsive to insulin. ...

Related topics

• Hypoglycemia
• Hyperglycemia
• Glucose
• Diabetes

Hypoglycemia is a medical term referring to a pathologic state produced by a lower than normal amount of sugar (glucose) in the blood. ... Hyperglycemia or High Blood Sugar is a condition in which an excessive amount of glucose circulates in the blood plasma. ... Glucose (Glc), a monosaccharide, is one of the most important carbohydrates. ... This article is about the disease that features high blood sugar. ...

External links

• Glucose test. Medline Plus.
• Blood glucose monitoring. Medline Plus.
• Glucose tolerance test. Medline Plus.