The superior thyroid artery carries oxygenated blood to the thyroid gland, which produces and stores the hormones L-triiodothyronine (T3) and L-thyroxine (T4). Thyroid diseases include hyperthyroidism, hypothyroidism, tumors, infections and autoimmune diseases. In tissue transplantation, the superior thyroid artery can serve in part as a donor for transplanted blood vessels.
What is the superior thyroid artery?
Medicine refers to the superior thyroid artery as the artery that supplies blood to the endocrine gland. The thyroid gland, or thyroid gland, is a hormone-producing organ that influences the metabolism of the human body and affects numerous other organs. The superior thyroid artery is part of the systemic circulation and accordingly carries oxygenated blood to the cells of the thyroid gland. For this purpose, the respiratory gas binds to red blood cells (erythrocytes), which absorb it in the lungs. Blood that has already delivered the oxygen flows back in the systemic circulation through the veins.
Anatomy and structure
From the external carotid artery, the superior thyroid artery branches off at the trigonum caroticum. This is the carotid triangle in the neck, located in the anterior cervical region. The trigonum caroticum is located there between the digastric muscle, the sternocleidomastoid muscle and the omohyoid muscle. Below the sternocleidomastoid muscle, the superior thyroid artery separates from the larger external carotid artery and continues to the thyroid gland (thyroid glandula). Viewed in cross-section, the superior thyroid artery has a wall that surrounds the lumen. The wall consists of a total of three layers. The tunica interna is the innermost of them and lines the blood vessel with an endothelial layer, over which lies another layer of connective tissue. The latter also belongs to the tunica intima. Above this is the tunica media, which houses the muscles of the blood vessel. With its help, the superior thyroid artery can dilate or constrict, thereby regulating blood flow. Beyond smooth muscle, the tunica media includes collagen and elastic fibers to provide adequate flexibility. Finally, the outermost layer of the artery is the tunica externa. It too contains collagen, elastic fibers and connective tissue. It primarily performs a protective function. It may also contain fine blood vessels (vasa vasorum), which are responsible for supplying cells to the middle and outer layers.
Function and tasks
The function of the superior thyroid artery is to supply blood to the thyroid gland. In the neck, the thyroid gland is located in front of the trachea at its upper end. A capsule encloses the endocrine gland, which has many capillaries. In order to pump sufficient blood into these fine blood vessels, the superior thyroid artery has a strong blood flow. In addition to the superior thyroid artery, the inferior thyroid artery, which is the inferior thyroid artery, is responsible for supplying the gland. The two arteries converge in front of the thyroid gland; physiology refers to this connection as an anastomosis. While the superior thyroid artery supplies blood mainly to the upper part of the gland, the inferior thyroid artery is responsible mainly for the lower part. The thyroid gland produces and stores the hormones L-triiodothyronine (T3) and L-thyroxine (T4). L-thyroxine functions in part as a precursor to L-triiodothyronine and in this function is considered a prohormone. In its abbreviation T4, the number refers to the number of iodine molecules that the hormone contains; L-thyroxine also has the alternative designation tetraiodothyronine for this reason. L-triiodothyronine increases the release of insulin, which regulates blood sugar levels and is also a hormone. Insulin is produced in the pancreas. In addition, L-triiodothyronine stimulates carbohydrate, protein and fat metabolism. Growth, heat production, water balance, oxygen consumption, nerve and muscle function are also subject to the influence of the thyroid hormone.
Diseases
In the context of microsurgical tissue transplantation, the implanted tissue sometimes requires a new connection to blood vessels to receive oxygen, nutrients, and energy (e.g., in the form of glucose).For transplants in the neck region, surgeons sometimes use the superior thyroid artery because it has a powerful blood flow. An artificial anastomosis – if the appropriate conditions are met – connects these blood vessels to the superior thyroid artery. The thyroid gland, which is dependent on the supply from the superior and inferior thyroid arteries, can contribute to the development of numerous medical conditions. Because thyroid hormones affect energy metabolism and other processes, individuals with an underactive endocrine gland (hypothyroidism) often suffer from fatigue, lack of energy, weight gain, lack of appetite, dyslipidemia, constipation, hair loss, dry skin, and bradycardia. Hypothyroidism can also cause myxedema, leading to coma in some sufferers. Heart failure and other complications are also possible in hypothyroidism. In contrast, hyperthyroidism is typically associated with increased activity, agitation and restlessness. The promoted metabolism often leads to unwanted weight loss, which may be accompanied by increased appetite. Nevertheless, affected individuals may suffer from weakening of muscles and/or muscle tremor (tremor). Other symptoms include hypertension, arrhythmias, sleep and menstrual disturbances, digestive problems, hair loss, and heat intolerance. A severe complication of the disease is thyrotoxic crisis, which can lead to coma and is potentially fatal. There are many causes of thyroid disease. Neoplasms such as thyroid adenoma, thyroid carcinoma, or other tumors can disrupt the function of the organ – but so can infections and autoimmune diseases such as Hashimoto’s thyroiditis, Ord thyroiditis, or Graves’ disease.