VI Международная студенческая научная конференция Студенческий научный форум - 2014

The thyroid gland (glandula thyroidea) - endocrine gland in vertebrates, which keeps iodine and produces iodine-containing hormones (iodothyronine) - thyroxine and triiodothyronine, which participate in the regulation of metabolism and growth of individual cells and the organism as a whole.

The average weight of an adult human thyroid is 15-30 g, and depends first of all on the content of iodine in the diet. Women’s gland slightly larger than men, and it increases significantly during pregnancy and lactation. Thyroid volume in women is to 18 ml, in man – to 25ml.

The thyroid gland is located in the neck below the larynx to the trachea. In humans, it has the shape of a butterfly and it is under the thyroid cartilage.

The thyroid gland is composed of two lobes (lobus dexter et sinister) and isthmus (isthmus). Approximately one-third of people have extra pyramidal share (lobus s. Processus pyramidalis). The right and left parts abut directly to the trachea, the isthmus is located on the front surface of the trachea. Right and left share covered by a. carotis commuuis, v. jugularis, n. recureus, parathyroid glands. In front thyroid covered by m. sternohyoideus, Sternothyreoideus, m.sternocleidomastoideus and platysma.

The thyroid gland is covered by own sheath (tunica fibrosa) and the capsule (capsula externa). Thyroid capsule is not soldered and can be relatively easily released from it, that really matter in operations.

Thyroid supplied with blood from four arteries: two upper thyroid arteries, right and left, and two lower, right and left, at 10% there is also a. thyroidea ima. The intensity of thyroid blood circulation is extremely high.

Thyroid has both sympathetic and parasympathetic innervation. Fibers from sympathetic innervation originate from the of the cervical ganglia and form the upper and lower thyroid nerves (nn. thyreoidei superior et inferior). The parasympathetic innervation is carried by branches of the vagus nerve - superior laryngeal and recurrent laryngeal nerve, derived from g. nodosum.

Thyroid activity is controlled by the hypothalamus and pituitary. The hypothalamus produces releasing hormones that stimulate the production of thyroid stimulating hormone (TSH) by the anterior pituitary. TSH stimulates the thyroid hormone activity. Lesions of the pituitary and hypothalamus, iodine deficiency, inflammatory and neoplastic processes in the thyroid gland inevitably lead to changes in hormonal levels and disorder functions almost all organs and systems.