The thyroid gland is one of the endocrine organs of the human body, endocrine organs being those which specialize in producing hormones and releasing them into the bloodstream. Hormones are extremely important compounds, since they contribute to the correct functioning of our organism. Their purpose is to give signals to other organs and tissues, which is why they're also known as chemical messengers. You can imagine a hormone as a letter from one cell to another cell or organ which lets them know what to do right now. The thyroid gland produces three important hormones, triiodothyronine (T3) thyroxine (T4) and calcitonin.
Anatomy of the thyroid gland
The thyroid gland consists of two lobes connected by a thin bridge, found on the front of the neck, in front of trachea and under the thyroid cartilage. A gland that is not swollen should not be visible unless some neck muscles are located asymmetrically, the neck spine is bent, or unless the person in question has a very thin neck. The gland has a dark red color and smooth surface. It has an abundant blood supply, which is beneficial for easy release of its hormones into the bloodstream. A fibrous sheath covers the surface of this organ, with protrusions into the gland's tissue. These protrusions divide the lobes into smaller lobules and smaller arteries run through them. Each lobule is then made out of a large amount of follicles, which are spherical sacs filled with a very specific mucous matter called colloid.
There usually are parathyroid gland firmly attached to the back of the thyroid gland, while their amount may vary from person to person, there usually are 4 of them, 2 pairs on both the top and bottom of the thyroid. These are also a part of the body's endocrine system, since they produce, which increases the amount of calcium in blood.
Function of the thyroid gland
The thyroid's tissue consists of several types of cells. Most common are the follicular cells (thyrocytes), whose purpose is to participate in producing triiodothyronine and thyroxine. Iodine, which the gland absorbs from the bloodstream, is necessary for their production. This is why its important to receive a sufficient amount of this element in diet, to allow the thyroid hormones, which are indispensable for our organism, to be produced in the amounts needed. Triiodothyronine and thyroxine participate in many metabolic processes, increase the production of proteins, the breaking down of fat, the accelerate processes within cells and influence oxygen consumption. Their function in the development of brain in children is also vital.
Different cells found in the thyroid produce calcitonin. This hormone participated in calcium management, in order to keep its levels permanently stable. To be precise, it moves calcium from blood to bones, which also prevents osteoporosis. Its function is the opposite of parathormone, the hormone of parathyroid glands, which increase the amount of calcium in blood.
The purpose of the thyroid gland in organism
A correct functioning of the thyroid is extremely important for the organism's healthy operation. Unfortunately, this organ is prone to many diseases and outside influences. This makes the thyroid a place where endocrine disease develop most commonly. Very often we can encounter a swollen thyroid gland, its inflammations, both increased and decreased production of hormones, but also cancerous processes. Today, however, most of the thyroid diseases are easily treated, provided they are diagnosed early. This means that the patient's cooperation with the doctor and strict following of his treatment are of utmost importance.
Diseases of the thyroid gland
Women have four times higher probability of a thyroid disease than men. The most commonly encountered ones are a struma, hypothyroidism, hyperthyroidism and thyroid inflammation.
Struma or a goiter affects around 5% of the population. Several factors contribute to the development of a goiter, mainly a lack of iodine and issues with hormonal production. Smoking and intake of strumigens in diet, compounds which inhibit the absorption of iodine, also play their role. The treatment occurs at several levels – from simple observation of the development to radioiodine treatment to surgical removal.
Hypothyroidism, a decreased thyroid function afflicts 1% of the population. Above the age of 60, this grows to 5%. Hypothyroidism is a condition where the gland doesn't produce enough hormones. This manifests through an overall slowness of the organism. The patient is tired, sleepy, moves slowly and tires easily. Weight gain is common, as the organism retains fluids, which build up, especially in lower parts of the limbs and causes swelling of skin.
Hyperthyroidism on the other hand, is a condition where the gland produces an excess of hormones. The main symptoms are an overall acceleration of the organism, the patient suffers from sleep disorders and is tired. He appears hyperactive and often loses weight.