The Thyroid

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					An Introduction to the Thyroid

The thyroid gland is a primary gland in the endocrine system. The major characteristic of the
glands in the endocrine system is that they all secret hormones directly into the bloodstream.
The thyroid gland produces three hormones; thyroxine, tetraiodothrnine (T4), triiodothyronine
(T3), and calcetonin. The thyroid is located in the anterior part of the neck and lies below the
skin and muscle layers. The shape of the thyroid gland is very similar to that of a butterfly; it has
two lobes (wings) which are connected by an isthmus (body).
The main function of the thyroid gland is to regulate metabolism. It also contains about 25% of
the body’s iodine, obtained from one’s diet. A deficiency of iodine can result in hypothyroidism.
Other diseases include hyperthyroidism caused by excessive production of thyroid hormones,
goiters which are an inflammation of the thyroid, and thyroid cancer.

Quick Facts

Name: Thyroid
Location: The anterior part of the neck
Function: To regulate metabolism
Affected Organs: The thyroid hormone affects all physiological functions of your body.
Hormones Released: thyroxine, tetraiodothrnine (T4), triiodothyronine (T3), and calcitonin
Interesting Fact: The shape is very similar to that of a Butterfly.

Thyroid Cancer

         Thyroid cancer is a fairly rare form of cancer that develops from the cells of the thyroid
gland. This type of cancer affects approximately 1 in 1,000 people, and has a very high survival
rate with several successful treatments. There is no prevention to thyroid cancer, although there
is a high incidence of the disease in people who have been in exposed to radiation. Overall, there
is a fair amount of scientific knowledge on the causes and subtypes of thyroid cancer, creating
very effective and successful treatment method.
         Thyroid cancer is thought to be caused by a variety of environmental and genetic aspects,
including radiation or radiotherapy to the neck, and a genetic defect known as MEN2 syndrome
which originates from a mutated gene. Women are thought to be more predisposed to the disease
than men because it is slightly more common in women than in men, however, it is seen in all
age groups. Similar to the several causes of this cancer come the numerous forms of thyroid
cancer , each with varying degrees of severity.
         There are several types of thyroid cancer including papillary carcinoma, follicular
carcinoma, medullary carcinoma, and anaplastic carcinoma, which all originate from the cells of
the thyroid gland. Papillary carcinoma is the most common of the types of thyroid cancer, and is
tumor on the thyroid gland, which spreads slowly and rarely causes death. It is much more
common in women, seen in about a 3 to 1 ratio to men, and is most frequently diagnosed in those
of thirty to forty years. Follicular carcinoma is the next most common type of thyroid cancer,
being most well known for spreading from the thyroid gland, and reoccurring after treatment.
Medullary carcinoma is occuring most often when there are genetic ties, such as in families. This
form involves non-thyroid cells and requires a different method of treatment in comparison to
most thyroid cancer cases. Another form of thyroid cancer which requires varying methods of
treatment is anaplastic carcinoma, and is the most serious type of thyroid cancer. However,
anaplastic carcinoma is also a very rare form of cancer that spreads quickly disrupting the
trachea , which then causes difficulties in breathing and compression. With each of these forms
of thyroid cancer also come numerous treatments, which are more often than not effective and
        There are several methods for the treatment of thyroid cancer, each causing the different
forms of the disease to react differently. Surgery, at this point in time, is the most common and
effective procedure in the treatment of thyroid cancer. In this process the entire thyroid gland is
usually removed, as will the lymph nodes if the cancer has spread past the thyroid gland.
Radiation therapy is another common treatment for thyroid cancer, whether surgery has been
preformed or not. This process matches well with surgery because it kills any cancer cells which
were left from the operation, and decreases the chances for a reoccurrence. Unfortunately,
though, this treatment does not work for some forms of the cancer. Chemotherapy becomes a last
option for thyroid cancer, mostly because it is not very successful, effecting only about one third
of those with thyroid cancer. However, doctors use chemotherapy treatment when other
treatments have failed. With the fairly aggressive approach that doctors take to treat thyroid
cancer there are some subsequent effects of the treatment methods, however they are very
        After receiving treatment for thyroid cancer, a thyroid hormone must be taken to replace
the function of the gland, as an effect of the aggressive treatments, including the removal of the
gland. The dosage that is taken is often higher than the level of the hormones, which the thyroid
gland would secrete, aiding in decreasing the chances of a reoccurrence. Ways to check for a
reoccurence are the same as those methods that were used to diagnose the cancer, including a
biopsy, an ultrasound of the thyroid gland, a thyroid scan that shows the cold nodule, or a blood
test. The most difficult factor in diagnosing thyroid cancer is that there is no screening test
available. This soon may change, though, as scientist have now developed a screen test for the
mutated gene that causes MEN2 syndrome which may soon lead to easier and faster testing for
thyroid cancer.

Dear Hoefer

Dear Hoefer,
       My young son has recently had a decreased appetite. I make him his favorite foods and
he only eats a couple bites. I have also noticed that there is some swelling in his neck. He
doesn’t complain of pain, but I am worried. What could be the cause of this and what can I do
for him?

- Worried in Omaha

Dear Worried
        It appears that your son has a thyroid abnormality known as hypothyroidism The thyroid
gland is responsible for the secretion of throxine and triiodothyronine which are hormones that
regulate metabolism. A deficiency of these hormones would cause a decreased appetite as you
described, and is often the result of a lack of iodine in the diet. The thyroid, in an attempt to
make up for the lack of iodine in the diet, may swell to become a simple goiter. The swelling you
describe may be the beginning of a simple goiter. As your son is a developing child, this problem
should not go unchecked. Hypothyroidism can lead to a disease known as cretinism. This is
characterized by low metabolic rate, retarded growth and sexual development, and possibly
mental retardation. Iodized salts can be taken to reduce the swelling thyroid, and you should
consult your doctor for further help. Peace out

- Hafe

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