DISEASES OF THE THYROID GLAND.
BY D. HAYES AGNEW, M.D., LL.D.
The thyroid body occupies a very important position in the neck, being closely related to the larynx, the trachea, the carotid blood-vessels, the pneumogastric, sympathetic, and recurrent laryngeal nerves. These relations render quite intelligible the phenomena which are so frequently present when the gland becomes the subject of disease. It is richly supplied with blood-vessels from the external carotids and the subclavian arteries.
Notwithstanding the obscurity which enshrouds the physiological function of the gland, there are good reasons for supposing that its office in the animal economy is not an unimportant one: indeed, its presence, not in the vertebrata alone, but also in birds, reptiles, and fishes, tends to strengthen this conclusion. The experiments of Zesas appear to show that the thyroid body plays an important rôle in regulating the supply of blood to the brain, and also of supplementing the work of the spleen. The place, therefore, of the gland in the body as an appendage to the vascular system appears to be well chosen.
Congenital absence of the thyroid body is uncommon, though it has been noted by a few writers. Curtin1 met with one case in which the gland was replaced by a mass of fat. Possibly in this instance the fat was the result of a morbid change in the thyroid, and not an evidence of the latter having never been present. Beach2 furnishes another case where on dissection no trace of the gland could be found. Hyrtl speaks of the isthmus being frequently absent—a fact observed by other anatomists.
1 Lancet, 1850, vol. ii. p. 25.
2 Medical Times and Gazette, May 30, 1884, p. 603.
Goitre.
Various names have been employed by different writers to designate enlargements of the thyroid body. Among these may be named bronchocele, tracheocele, thyrophraxia, Derbyshire neck, struma, and goitre. Among English-speaking people the disease is generally spoken of as goitre or Derbyshire neck.