Thyroid stimulating hormone and thyroxine

Thyroid stimulating hormone and thyroxine
Thyroid stimulating hormone and thyroxine

Occasionally, it is used to evaluate pituitary gland function. The TSH test involves analyzing a sample of your blood in a laboratory. To obtain a blood sample, a nurse will draw blood from a vein in your arm or the back of your hand.

Graves Disease Graves disease (thyrotoxicosis) is due to a unique antibody called "thyroid stimulating antibody" which stimulates the thyroid cells to grow larger and to produce excessive amounts of thyroid hormones.

Hypothalamic - Pituitary - Thyroid Axis. The thyroid gland is influenced by hormones produced by two other organs: The pituitary gland, located at the base of the brain, produces thyroid stimulating hormone (TSH) The hypothalamus, a small part of the brain above the pituitary, produces thyrotropin releasing hormone (TRH).

But, TSH has a second action - it causes growth of thyroid cells. The gland grows and becomes very large under the influence of this high level of TSH secretion. Therefore, most people who live in iodine deficient areas have goitre, thus allowing them to produce enough thyroid hormone for normal body function.

Normal free thyroxine

Iodine. Iodine plays an important role in the function of the thyroid gland. It is the chief component of thyroid hormones, and is essential for their production. Iodine is obtained from the water we drink and the food we eat.

Low levels of thyroid hormones in the blood are detected by the hypothalamus and the pituitary. TRH is released, stimulating the pituitary to release TSH. Increased levels of TSH, in turn, stimulate the thyroid to produce more thyroid hormone, thereby returning the level of thyroid hormone in the blood back to normal.

It is sometimes called a thyrotropin test. TSH is a hormone produced by the pituitary gland that tells the thyroid to make and release thyroxine (T4) and triiodothyronine (T3). Together, these essential hormones help control the rate at which the body uses energy.

The thyroid gland is under the control of the pituitary gland, a small gland the size of a peanut at the base of the brain (shown here in orange). When the level of thyroid hormones (T3 T4) drops too low, the pituitary gland produces Thyroid Stimulating Hormone (TSH) which stimulates the thyroid gland to produce.

These cells combine iodine and the amino acid tyrosine to make T3 and T4. T3 and T4 are then released into the blood stream and are transported throughout the body where they control metabolism (conversion of oxygen and calories to energy).

In the later stages, the goitre can disappear because of the progressive destruction of the thyroid. Thyroid Nodules. Sometimes, thyroid enlargement is restricted to one part of the gland; the rest of the gland being normal.

The function of the thyroid gland is to take iodine, found in many foods, and convert it into thyroid hormones: thyroxine (T4) and triiodothyronine (T3). Thyroid cells are the only cells in the body which can absorb iodine.

An underactive thyroid gland ( hypothyroidism ) can cause symptoms such as weight gain, tiredness, dry skin, constipation, a feeling of being too cold, or frequent menstrual periods. An overactive thyroid ( hyperthyroidism ) can cause symptoms such as weight loss, rapid heart rate, nervousness, diarrhea, a feeling of being too hot, or irregular menstrual.

For infants and small children, a lancet (a small instrument similar to a scalpel) is used to puncture the skin. The blood sample collects in a small glass pipette or on a test strip or slide.

"Autoimmune disorders" of the thyroid gland are the most common cause of thyroid dysfunction. These autoimmune disorders are caused by abnormal proteins, (called antibodies and the white blood cells which act together to stimulate or damage the thyroid gland.

One might imagine the hypothalamus as the person who regulates the thermostat since it tells the pituitary gland at what level the thyroid should be set. Updated on: Thyroid Gland, How it Functions, Symptoms of Hyperthyroidism and Hypothyroidism.

It has two sides or lobes. These lobes are connected by a narrow neck (or isthmus). Each lobe is about 4 cm long and 1 to 2 cm wide. The name "thyroid" comes from the Greek word which means "shield".

Thyroid Disorders The main causes of thyroid disease are: too much thyroid hormone production or hyperthyroidism. too little thyroid hormone production or hypothyroidism. The state of normal thyroid function is called euthyroidism.

Under the influence of TSH, the thyroid will manufacture and secrete T3 and T4 thereby raising their blood levels. The pituitary senses this and responds by decreasing its TSH production. One can imagine the thyroid gland as a furnace and the pituitary gland as the thermostat.

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