For a single return trip from Paris to Brussels, a point to point ticket is the best value for money and the cheapest train ticket. Best prices are available when buying the train ticket well in advance. For extensive train travel, a rail pass for France and Belgium is a better choice.
creÂ·tinÂ·ism. n. A congenital condition caused by a deficiency of thyroid hormone during prenatal development and characterized in childhood by dwarfed stature, mental retardation, dystrophy of the bones, and a low basal metabolism. Also called congenital myxedema. (ËkrÉtÉªËnÉªzÉm).
Deficiency of thyroid hormone may be due to lack of stimulation by the pituitary gland, defective hormone synthesis or impaired cellular conversion of T4 to T3 (often caused by mercury toxicity). The pituitary gland regulates thyroid activity through the secretion of thyroid-stimulating hormone (TSH).The combination of low thyroid hormone and elevated TSH blood levels usually indicates defective thyroid hormone synthesis, which is defined as primary hypothyroidism.he thyroid gland captures dietary iodine, synthesizes thyroid hormone from it, and stores thyroid hormone until it is needed. Colloid, the material in the center of the follicles, stores thyroid hormone in a large protein called thyroglobulin.