Aetiology pathology Thyroid

The Aetiology and Pathology of Thyroid Disease

A Bhattacharyya and PG Wiles

The Thyroid gland is one of the largest endocrine organs, weighing approximately 15-20g in adults. The gland is composed of closely packed sacs, called acini or follicles, which are invested with a rich capillary network. The interior of the follicle is filled with proteinaceous material called colloid. The thyroid gland also contains parafollicular or C cells that are the source of the calcium lowering hormone, calcitonin. Normal function of the thyroid gland is to secrete thyroxine (T4) and triiodothyronine (T3).The active principles with various influences on metabolic processes. T3 is the more metabolically active of the two, and is mostly produced from T4 in the peripheral tissue, mainly in the liver. Thyroid stimulating Hormone (TSH) is the trophic hormone, secreted from thyrotrophs of the anterior pituitary gland, which stimulates the secretion of thyroid hormones from the thyroid gland. TSH is regulated by thyrotrophin releasing hormone (TRH).

Hospital Pharmacist 2000;3:5-13