The thyroid gland / by Charles H. Mayo and Henry W. Plummer.

  • Mayo, Charles H. (Charles Horace), 1865-1939.
Date:
1925
Catalogue details

Licence: Public Domain Mark

Credit: The thyroid gland / by Charles H. Mayo and Henry W. Plummer. Source: Wellcome Collection.

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    Development of the Thyroid During fetal life the developing thyroid is peculiarly susceptible to influences which impair the mother’s I thyroidal resources. It responds to these influences by undergoing hypertrophy or hyperplasia, or cell-death or fibrosis. It is, therefore, important to exclude all in¬ fluences which depress or unduly strain the maternal thyroid. For this reason it is sometimes wise to in¬ quire into the antenatal history of backward children ( and to examine the mothers for thyroid defect. The thyroid apparatus of the fetus and of young infants contains little or no iodin. At this period of l life the thyroid is more cellular and the vesicles smaller I and fewer, containing less colloid than in later years. Apparently nature does not intend the organ to attain full functional perfection until some months after birth I nor is this gland called on to exercise its full powers l during the earlier months of life. This is due to the f fact that the maternal thyroid continues in a state of heightened activity throughout the earlier months of lactation, during which time the infant derives from J its mother’s milk, part, at least, of the thyroid secretion \ which it needs. Cow’s milk does not provide this f thyroidal element in the same degree or kind. There- f fore, no form of infant feeding can replace the mother’s f milk. I With the cessation of suckling and with the com- i mencement of taking more solid food, the thyroid ap- * paratus of the child begins to act for itself, elaborating 1 its secretion from the raw materials of the food and * responding to every call made on it by the processes of ' increasing growth and the maturation of the bodily 1 functions. < i Throughout child life the thyroid is in a state of con- i stant activity which may manifest itself, especially under