Introduction to Your Thyroid Gland

Functions of the Thyroid Gland

The thyroid gland is found in front of the trachea (wind tube) in your neck. The gland is divided into 2 lobes (right and left) and is connected in the middle by a thin bridge of thyroid tissue, known as the isthmus. Because of the 2 connected lobes, the thyroid has been described as being shaped like a butterfly.

The thyroid cartilage, which is the largest cartilage of the larynx( voice box) lies simply above the thyroid gland and is sometimes known as the Adam’s apple.

A normal-sized thyroid gland cannot be seen in the neck, and can scarcely be felt. It is only when certain conditions result in an enlarged thyroid gland (known as goitre ), that a bulge may be seen or felt simply underneath the Adam’s apple.

What is the function of the thyroid gland?

The primary function of your thyroid gland is to secrete thyroid hormones which are involved in regulating many of your bodily functions

Breathing rate
Heart rate
Body Temperature
Metabolism – How quickly you burn calories
Digestion
Babies and children require adequate amounts of thyroid hormones for brain development and growth.

Your thyroid requires iodine( a mineral that’s an essential part of our diet) in order to manufacture these thyroid hormones.

Functions of the Thyroid Gland

What hormones does the thyroid gland secrete?

The 2 main thyroid hormones are T3 triiodothyronine and T4 thyroxine. T3 and T4 regulate your body’s temperature, metabolism and heart rate.

The amount of thyroid hormones secreted are dominated by another hormone, called thyroid stimulating hormone( TSH ), which is released from the pituitary gland in your brain. TSH stimulates the thyroid to construct T3 and T4. Blood tests are done for TSH levels when doctors investigate for thyroid illnes. T3 and T4 may also be tested for.

Calcitonin

Another hormone that’s produced in your thyroid gland is called calcitonin. This hormone, secreted by a small population of cells known as C cells, actively participate in regulating the level of calcium and phosphate in your blood.

The levels of calcitonin are driven by the amount of calcium in your blood. When your blood calcium levels lessen, less calcitonin is secreted and vice versa- when your blood calcium levels increase, levels of calcitonin increase. Calcium and phosphate are both involved in the formation of bones.