Weight
Loss and Thyroid
Weight
Loss Sabotage
by Kristy Haugen
The
thyroid is a gland located on the anterior (front)
portion of the neck attached to the upper part of
the trachea (windpipe). The thyroid is a bi-lobed
gland. This gland is small in size, about 4 centimeters
long and 1-2 centimeters wide.
The
thyroid produces and secretes biologically important
hormones. Tissue in the thyroid is made up of two
different kinds of cells: follicular and parafollicular
cells. The thyroid is composed mostly of follicular
cells which secrete T3 and T4 hormones. The T4 hormone
(thyroxine) and T3 hormone (triiodothyronine) is
derived from the amino acid tyrosine during iodination
of the amino acid. Parafollicular cells secrete
the hormone calcitonin. Iodine is important in the
function of the thyroid gland. Iodine is a chief
component of the hormones produced by the thyroid
gland. Iodine deficiency can cause thyroid dysfunction,
hence the need for iodized salt. The thyroid also
produces and secretes the hormone calcitonin. The
hormone calcitonin decreases plasma calcium ions
concentration by inhibiting the release of calcium
ions from the bone. Calcitonin secretion is regulated
by plasma calcium ion levels.
The
thyroid plays a key role in regulating the body’s
metabolism. What is metabolism? Metabolism is a
chemical reaction that occurs in the body’s
cells, releasing energy from the nutrients ingested.
Metabolism also uses energy to create other biologically
important substances such as proteins. Basal metabolic
rate (BMR) is a measurement of the body’s
required energy to keep functioning at rest (measured
in calories). Exertion, stress, fear, and illness
increase the body’s metabolic rate.
The
thyroid has many other bodily functions. The thyroid
helps regulate calcium levels in the body. The thyroid
can increase the body’s temperature, thus
burning more calories. This in turn increases the
body’s appetite. The thyroid also promotes
glucose catabolism. Catabolism is the break down
of complex glucose forms into simpler, more usable
forms for energy usage. This gland stimulates protein
synthesis, increases lipolysis. Lipolysis is the
hydrolysis of lipids (fats), in which the lipids
are broken down into simpler or usable forms. The
thyroid also promotes normal heart function, normal
neural development in fetus and growing infants,
and normal neural function in adults.
The
thyroid is influenced by hormones produced by the
pituitary gland and the hypothalamus. The pituitary
gland is located at the base of the brain. This
gland produces thyroid stimulating hormone (TSH).
TSH stimulates the thyroid gland to absorb iodine
and then synthesize and release thyroid hormones.
The
hypothalamus is located above the pituitary gland
in the brain. This hormone produces thyrotropin
releasing hormone (TRH). The hypothalamus and pituitary
gland detect low levels of thyroid hormones in the
blood. TRH is released by the hypothalamus to stimulate
the pituitary gland to release TSH. TSH in turn
stimulates the thyroid gland to produce more T3
and T4 hormones. This returns the thyroid hormone
levels in the blood back to normal.
Inflammation
of the thyroid or a deficiency in iodine causes
the condition called hypothyroidism. The thyroid
hormones become under secreted or are not secreted
at all with hypothyroidism. Hypothyroidism symptoms
include fatigue, slowed heart and respiratory rate,
cold intolerance, and weight gain. Newborn infants
with hypothyroidism (cretinism) are characterized
by mental retardation and short stature.
The
thyroid can also be over stimulated in a condition
termed hyperthyroidism. This results in over secretion
of the thyroid hormones. Symptoms associated with
this disorder include an increased metabolic rate,
profuse sweating, heart palpitations, weight loss,
protruding eyes, and a feeling of excessive warmth.
With both conditions the thyroid often enlarges
resulting in goiter. However, goiter does not always
indicate disease. Thyroid enlargement can result
during pregnancy and puberty.
If
you exhibit some of the above symptoms, you should
consult your physician for further follow up. Many
women due have serious concerns regarding their
thyroid gland. If you have tried to lose weight
with no success, maybe it is due to the thyroid.
Kristy Haugen may be contacted at http://www.vitaminmaniac.com
khaugen@vitaminmaniac.com. I am a mother working
to finish my second bachelor degree in Chemical
Engineering. I am also a Licensed Practical Nurse
with a current bachelor degree in Biology and Chemistry.
I am writing to quench my thirst for knowledge.
View more articles at http://www.vitaminmaniac.com/liquid_vitamin_articles/
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professional advice. Always check with your Physician
before starting any weight loss or exercise program.
