Endocrine System

Fiona White

Physiology & Anatomy

Endocrine System

What is Goitre?

Goitre is a term applied to a swelling in the front of the neck resulting in the enlargement of the thyroid gland. The size of the swelling can vary and in extreme cases the swelling can be very prominent and cause discomfort from its pressure on the windpipe and other important parts of the neck.

What causes Goitre?

Goitre is caused by the over production of thyroxine (hyperthyroidism) which leads to a condition known as exophthalmic goitre. It is called this due to the large swelling in the throat and because the eyeballs protrude. Sufferers with hyperthyroidism will generally have an increased metabolic rate, the heart beats faster and together with a general restlessness both physically and mentally, and they will have dramatic weight loss and almost always develop Goitre.

Thyroid deficiency is either due to an under active thyroid gland (hypothyroidism) or poor diet resulting in an iodine deficiency. Endemic Goitre is where certain regions, mostly valleys and elevated plains in mountainous areas are devoid of iodine in their diet due to poor soil quality and the lack of green leafy vegetables and fish. The thyroid is an endocrine gland which produces TSH (thyroid stimulating hormone) known as thyroxine. This controls the body’s basal metabolic rate and affects growth. If the thyroid gland is inadequately stimulated by TSH insufficient thyroid hormones are secreted & the metabolic rate slows down. The most obvious symptoms are weight gain and lethargy. However, if hypothyroidism occurs in developmental years this can result in an abnormal growth and mental retardation, such as cretinism.

How can Goitre be Treated or Prevented?

Goitre can be treated by the use of anti-thyroid drugs or radioactive iodine, in some cases the use of thyroid hormone to block the hypothalamic mechanism that releases TSH. Other forms of treatment are partial or total removal of the thyroid gland. Now of course this can be carefully controlled & regulated by drugs such as thyroxine and radioactive iodine being injected in to the patient’s bloodstream or more simply by diet. However, with endemic Goitre it is far easier to treat. In regions of Switzerland, the great Lakes and Derbyshire where ...

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How can Goitre be Treated or Prevented?

What is Cretinism?

Cretinism is the condition caused by severe congenital hypothyroidism and is often associated with other endocrine abnormalities. It is either sporadic or endemic, the latter being due to an iodine deficiency. The most typical signs of Cretinism include dwarfism, mental deficiency and puffy facial features, an enlarged tongue, umbilical hernia and muscular incoordination.

What causes Cretinism?

The causes of Cretinism are either the congenital absence of the thyroid gland, an under active gland due to being under developed or as a result of Goitre. The endemic form of Cretinism has been recognised throughout many parts of the world, such as the Pyrenees and central Switzerland and certain regions of the UK. Wherever endemic Goitre appears endemic Cretinism is present also. Some researchers² have shown that endemic Goitre is a result of drinking certain types of water, though they have not determined which particular impurity in the water causes the condition.

As with Goitre, endemic Cretinism occurs due to the absence of iodine in the diet. It is especially important whilst in the foetal stages and is sometimes hard to recognise up until the age of two. By the age of fourteen or fifteen Cretins may be so severely mentally retarded that they are unable to feed themselves as well as being stunted and pot-bellied.

How can Cretinism be Treated or Prevented?

If Cretinism is detected early enough in young children the use of the thyroid hormone can be a reasonably effective treatment and generally promotes normal physical growth but may not prevent mental retardation. The use of iodised salt will dramatically reduce the incidences of cretinism in the population and where possible green leafy vegetables and fish being introduced to the diet, although in certain regions such as Ecuador & the Himalayas this may not be so feasible.

Based on information taken from: