Diabetes Mellitus
The disease “Diabetes Mellitus” is a disorder of the islets of Langerhans in the pancreas; this prevents the body producing the hormone insulin, which therefore means the sugars of the body cannot be used properly. There are two types of Diabetes Mellitus, Type 1 occurs when the pancreas can’t produce enough insulin. Type 2 is that unlike type 1, in which the body can’t produce enough insulin, the body just doesn’t respond to insulin properly in type 2. Type 1 (insulin dependent) diabetes usually starts in early life and is an autoimmune condition, type 2 (non-insulin dependent) diabetes usually starts in later life, and patients, which suffer this type of diabetes, tend to be overweight.
Type 1 diabetes symptoms include excessive thirst, urination, weight loss and hunger. The disease can cause many long-term complications such as kidney problems, blindness, early coronary heart disease and strokes. Type 1 diabetics need daily insulin injection to control their blood sugar levels to reduce the risks of developing diabetic complications late on. Although some patients will have a continuous infusion of insulin from a catheter implanted under the skin and connected to an electrical pump, this imitates the secretion of insulin by the pancreas more naturally that daily injections.
The symptoms for type 2 diabetic as are the complications are somewhat similar to those of type 1 diabetics although patients tend to be over weight, it is believed that the excess body fat plays a role in the resistance to insulin that characterises the disease. Most patients with this type of diabetes can control their condition with strict diet restrictions and exercise some may need oral medication
The production of insulin by the pancreas is in the form of a negative feedback mechanism. The blood sugar level rises in the presence of glucagon so the pancreas secretes insulin, which lowers the glucose levels in turn stopping the secretion of insulin by the pancreas. When this malfunctions diabetes mellitus can occur. The negative feedback mechanism of the pancreas is shown in diagram 2.
Diagram 2. This shows the negative feedback system of the pancreas.
Diabetes Insipidus
The much rarer form of diabetes, “Diabetes Insipidus” is not caused by the pancreas but by the pituitary gland, which is known as the master gland. The condition occurs when inadequate amounts of Antidiuretic hormone are produced by the posterior pituitary gland. A decreased ability in the kidneys to concentrate the urine is associated with this disorder resulting in excessive urination, thirst, body fluid and blood sodium level imbalances. Diabetes Insipidus can be inherited or can result in injuries of tumours in the pituitary of hypothalamus. It is controlled by hormone therapy by giving Antidiuretic hormone by pill, injection of intranasally (though the nose).
It is said that 4% of the worlds population suffers from one of the types of diabetes, many of which are undiagnosed and go, untreated. The number of people suffering from diabetes in the UK has doubled in the past twenty years.
Acromegaly
The anterior pituitary gland secretes six different hormones one of which is the growth hormone (GH) or somatrophic hormone. The bodies muscle and bone growth rate as well as the rate at which amino acids enter cells for which protein synthesis occurs is brought on by the growth hormone. As opposed to glucose metabolism by insulin, the growth hormone brings about fat metabolism. As most growing occurs during childhood and adolescence, this is when most of the growth hormone can be found in the body. When in adulthood too much GH is produced a condition known as Acromegaly occurs.
In adulthood long bone growth is no longer required and GH is not needed in such large amounts as in earlier years. When too much GH is produced the bones in the hands, feet and face (mainly the nose, shin and eyebrow bones) can respond to the growth hormone causing it to over-grow. As a person who suffers from Acromegaly ages, the toes, fingers and face bones continue to grow and enlarge. Other symptoms include: thick, coarse, oily skin; skin tags; enlarged lips, nose and tongue; deepening of the voice due to enlarged sinuses and vocal cords; snoring due to upper airway obstruction; excessive sweating and skin odor; fatigue and weakness; headaches; impaired vision; abnormalities of the menstrual cycle and sometimes breast discharge in women; and impotence in men. There may be enlargement of body organs, including the liver, spleen, kidneys and heart.
Treatment of Acromegaly includes drug therapy, surgery, and radiotherapy. Acromegaly can cause other diseases the most serious of these are diabetes mellitus, hypertension, and an increased risk of cardiovascular disease. They are also at risk for development polyps of the colon that can develop into cancer. The picture below shows some of the effects that Acromegaly can cause.
Diagram 3. Pictures of the outcome of some symptoms of Acromegaly.
Addison’s Disease
Addison's disease is the condition that develops when the adrenal cortex hormones are low due to hyposecretion. The ineffective but excessive presence of ACTH causes the skin to bonze, due to a build up of melatonin, which can also occur in the presence of MSH. Other symptoms of Addison’s disease include weight loss, anaemia, weakness, low blood pressure and digestive upset. Addison’s disease is named after the man Thomas Addison, a London physician who first described it 1849 and more fully in 1855.
Addison’s disease is not common in children and those over 60; it’s most common in people in there 20s and 30s. There is no cue for Addison’s but people suffering from it can lead a normal life with the help of replacement therapy. In the past many people with the condition died from it after what seemed a relatively short illness and this baffled doctors. An autoimmune disease or tuberculosis mostly causes the condition.
Diagram 4. This diagram below shows the feedback mechanism of the pituitary gland in aspect into the hormones that when malfunction cause Addison’s disease.
Many other conditions can occur from malfunctions of the endocrine glands, some of these disorders can be fatal others can be treated with replacement hormones and surgery. In order for our bodies to remain in a constant stable state, Homeostasis, it is required that all of the functions of every part of our body including the endocrine system have to work together properly.
Bibliography
Sylvia S. Mader “Biology” Eighth Edition
Hutchison’s Reference Encyclopaedia 2000
Search engine Google for various web sites.
