AFFECTIONS OF THE THYROID GLAND The manifestations of disturbed or absent secretion of the thyroid will, as a matter of course, be apparent in the entire organism in propor tion to its state of development. Owing to the smallness of the upper thoracic aperture and the possibility of considerable compression of the trachea and the larger vessels in the child, even quantitative changes' such as acute swelling or rapid growth of benign goitre, may lead to serious manifestations. the present time the importance of the thyroid is enhanced from a pediatric point of view owing to our increas ing knowledge of its etiologic importance in retarded physical and mental development, which, being based upon an insufficiently developed thy roid, is surprisingly amenable to organotherapy. Its brilliant success in infantile myxicliocy, CVell in endemic goitre and cretinism, makes a thorough understanding of the thyroid functions eminently desirable.
The thyroid is a pair-organ,. the component parts of which are con nected by a low bridge. In children it is situated higher than in the adult, closely hugging the lateral part of the tracheal ring, often in the shape of date-kernels, in the fossa formed by the trachea and the cesoph agus. Its smooth, tense capsule is often permeated by a layer of fat which itnperceptibly loses itself in the submucous adipose tissue of the neck. It is impossible even approximately to judge of the size or the
presence of a normal thyroid gland, much less on the conditions of a flattened thyroid or one that is displaeed posteriorly. Any statements in regard to absent thyroids in a normally nourished child, based upon examinations of living individuals, are therefore valueless. It is quite an ordinary occurrence to find at autopsy a normal or even large thyroid in cases where, during life, even the experienced physician would not have been able to prove its existence. On the other hand, slight swelling of the medial lobe or of the right lobe, which is generally enlarged in the presence of considerable venous stasis, as in diphtheria, whooping cough, broncho-pneumonia or rachitis, during life, is often responsible for considerable over-estimation.
In regard to the physiological significance of the thyroid, I may refer to the introduction to the chapter on Athyreosis.
So far as disturbances are concerned which occur in the normal func tion of the organ, there should be considered congestion, acute and chronic inflammation of the thyroid and the development of goitre, unless these conditions are present as sequelm to surgical interference.