Endocrinology AMAZING HORMONES

Counterbalance of Sugar and Fat Content between Insulin and Glucagon

Physical survival depends on the sustained availability and use of energy in the form of adenosine triphosphate or ATP from sufficient levels of a substance, called glucose (Bowen, 2001). The use of energy depends on the varying levels of activity. Hence, the amount of glucose needed for activity likewise varies each day. Too much or too little glucose is damaging to the body, hence the need for some system to regulate the availability of glucose. It must be present at the precise time and amount that it is needed in order to maintain what is called glucose homeostasis. Homeostasis is the tendency of the body to maintain internal stability and balance through the coordinated responses of body parts to stimuli or conditions (Bowen).

Insulin and Glucagon

The regulation of glucose availability begins with the pancreas, primarily by its production of the two antagonistic hormones, insulin and glucagon (Biomed, 2002; McGinnis, 2013). Insulin is the hormone produced and released by the pancreas when glucose levels get too high. Glucagon, in contrast, is that it produces and releases when glucose levels fall too low. Too much glucose in the blood is deadly to the cells, while too little can lead to starvation (Biomed, McGinnis).

Blood glucose levels are unstable as they change for different reasons (Biomed, 2002; Bowen, 2001; McGinis, 2013). These include digestion after eating and the release of insulin by the liver; the transport of glucose into the cells or its loss by urinating. The body first detects glucose in the bloodstream by receptors alpha cells and beta cells. Rising glucose levels prompt beta cells to produce insulin, which restores glucose levels to normal. At the same time, it signals body tissues to use glucose for energy. What is not used is converted to glycogen and lipids and stored in the liver as reserves. When glucose levels fall, on the other hand, alpha cells release the opposite or antagonistic hormone, glucagon to bring about the breakdown of glycogen into glucose and adipose tissue by skeletal muscle and liver. These organs digest lipids into fatty acids and glycerol. Glucagon furthermore causes the liver the synthesis of glucose from glycerol in the blood by the liver. These actions and reactions synergize and restore glucose levels to normal again. Thus do the insulin and glucagons counterbalance each other in maintaining glucose homeostasis (Biomed, Bowen, McGinnis).

Glycogenolysis

After the body uses needed glucose for functioning and brain power, un0used glycogen is stored in the liver and muscles through a process called glycogenesis (Bowen, 2001; Biomed, 2002; McGinnis, 2013). After activity or exercise, the body will automatically replace the stored glycogen used in the activity as soon as food is ingested. If the replacement does not occur or the reserve is depleted, the body turns to protein and breaks it down as source of energy (Bowen, Biomed, McGinnis).

Conclusion

The balance and control asserted by these hormones regulates tissue metabolism and blood levels of glucose, fatty acids, triglycerides and amino acids (Medbio, 2013). They are behind the maintenance of homeostasis on a minute-to-minute basis. Promoting it insures the body's integrated metabolism and stability of the body. Glucose is the key molecule in the process. Cells must receive a controlled amount for survival and health. Thus regulating glucose level in the blood is essential to maintain homeostasis (Medbio).

II. Effects of Epinephrine

Introduction

Epinephrine is a catecholamine hormone, secreted by the adrenal medulla in response to hypoglycemia, stress and other stimuli (The Free Medical Dictionary, 2013). It strongly stimulates the sympathetic nervous system and is also a powerful vasopressor. It raises blood pressure, stimulates the heart muscle, speeds up the heart rate and increases heart activity. It is also called adrenaline (The Free Medical Dictionary). It affects:

nutrient metabolism

Epinephrine increases the production of glucose by stimulating glycogenolysis and gluconeogenesis (Sherwin & Sacca, 1964). While its effect on glycogenolysis quickly dissipates, hyperglycemia persists because of its effect on gluconeogenesis and continued glucose disposal. Hyperglycemia is further enhanced by increased glucagons and cortisol or in diabetic persons. In either case, epinephrine's effect on the production of glucose by the liver changes from a temporary to a sustained response or an exaggerated hyperglycemia. Epinephrine thus exposes diabetics to the adverse metabolic effects of stress. During glucose feeding, a small increase in epinephrine with little effect on fasting glucose levels can develop marked glucose intolerance. Its sensitivity to the diabetogenic effects of epinephrine derives from its capacity to interfere with the components of the gluco-regulatory response. These include the stimulation of splanchnic and peripheral glucose uptake and the suppression of glucose production by the liver (Sherwin and Sacca).

Exposure to cold temperature makes the skin temperature drop. Both the hypothalamic thermostat and higher cortical centers will sense this. The thermostat will promote heat gain and prevent heat loss. One response to the activation of sympathetic centers is the secretion of epinephrine by the adrenal medulla, which increases thermogenesis (Dabrowski).
cardiovascular system

One of the most easily recognized effects of epinephrine is increased heart rate (Kilpatrick, 2013). Both epinephrine and norepinephrine are released at the same time to respond to stimulus. Epinephrine acts faster by increasing the frequency of heartbeats. Norepinephrine, on the other hand, constricts blood vessels. Their combined effect is stronger heartbeats, increasing blood pressure and respiration and more blood into the muscles. They enable quick physical response to emergency (Kilpatrick).

Respiration

Epinephrine affects the peripheral nervous system by either stimulating or inhibiting (Schuster, 2010). It stimulates the central nervous system by promoting respiration and increasing muscle activity. It stimulates smooth muscle cells and blood vessels, the heart rate and the force of muscle contractions. Its functions are balanced by those of norepinephrine (Schuster).

Conclusion

Similar to insulin and glucagons, epinephrine and norepinephrine perform opposing or balancing functions (Schuster, 2010). They are chemicals or hormones, which dictate metabolic processes, which antagonize and complement each other (Schuster).

III. A Diabetes

Introduction

This is a condition wherein the level of glucose or blood sugar is too high (NDIC, 2013). Glucose comes from ingested food and from the liver and muscles, which store it. Blood carries glucose to all the body cells in order to perform their respective functions. The pancreas produces a hormone called insulin to help bring glucose to the cells. But when there is not enough insulin to do this or insulin malfunctions, glucose cannot get into the cells, which need them for survival. It stays in the blood and accumulates. When its level gets too high, pre-diabetes or diabetes may develop. The three types of diabetes are type 1, type 2 and gestational diabetes (NIDC).

Type 1 and Gestational Diabetes

This type is also called juvenile diabetes or insulin-dependent diabetes (NIDC, 2013).

The body's immune system attacks and then destroys the beta cells in the pancreas, which manufacture insulin. Treatment includes insulin shots, another injectable medicine, a special diet, physical activity, daily aspirin and controlling blood pressure and cholesterol. Gestational diabetes develops only in pregnant women and in the late states of pregnancy. The hormones of pregnancy are responsible for this type. A woman who develops it is likely to develop type 2 at a later age (NIDK).

Type 2

Also called adult-onset diabetes or non-insulin-dependent diabetes, is the most common form (NIDK, 2013). Anyone can develop it at any age, even during childhood. It usually starts with insulin resistance when fats, muscle and liver cells fail to utilize insulin properly. The pancreas initially responds to the need for more insulin until it loses the ability to adjust to increased demand. Those who develop it are usually overweight and/or physically inactive or have a sedentary lifestyle. Treating this type takes a lifetime. It includes taking diabetes medicines, eating only the recommended diet, sustained physical activity, daily aspirin intake and no letup control of blood pressure and cholesterol..Health authorities estimate that almost 26 million adults and children in the United States or 8.3% of the entire population have diabetes (NIDK, 2013). Of this number, 18.8 have been diagnosed and 7 million are left undiagnosed. (NIDK).

B. Hyperthyroidism

This condition is characterized by thyroid hyperactivity and overproduction of the thyroid hormone (Zieve et al., eds, 2013). Persons who suffer from this condition stand a higher risk to develop diabetes mellitus. Youngest diabetics are prone to develop type 1 diabetes but older ones are more likely to develop type 2 diabetes. In this latter case, the mechanism is seen as more complex as it includes different aspects combining to enhance the development of insulin resistance and metabolic disorder Hyperthyroid patents require more insulin administration in the control of serum glucose levels. Type 2 diabetics should avoid thiazolidineione, which increases insulin sensitivity. And thyrotoxicosis and diabetic ketoacidosis may also occur simultaneously, especially with a depletion of potassium and intravenous insulin (Zieve et al., eds).

Conclusion

Thyroid abnormalities have been observed to coexist as well as interact with diabetes mellitus (Zieve et al., eds, 2013). Although thyroid dysfunction and goiter can occur in both diabetic and non-diabetics, expert find the need to evaluate…