MEDICAL BIOLOGY, HUMAN ANATOMY, PHYSIOLOGY AND PATHOLOGY - Y.I. Fedoniuk 2010

ANATOMY, PHYSIOLOGY, PATHOLOGY

SECTION 3. ANATOMICAL AND PHYSIOLOGICAL ASPECTS OF THE SELF-REGULATION OF BODY FUNCTIONS

ENDOCRINE GLANDS AND THEIR PATHOLOGY

THYROID GLAND

2. THYROID DISORDERS

2.3. ENDEMIC GOITER

Endemic goiter is an enlargement of The Thyroid Gland caused by iodine deficiency in the soil and Water.

In response to prolonged iodine deficiency in the body, a goiter develops, driven by several adaptive mechanisms. The synthesis of thyroglobulin and THYROID Hormones decreases, while the peripheral conversion of thyroxine to triiodothyronine increases. Pituitary secretion of thyroid-stimulating hormone rises, resulting in HYPERTROPHY AND HYPERPLASIA of the thyroid gland. In the Cytology/cytology/16.html">Early stages of the disease, this response may be compensatory, but it eventually progresses to goitrous transformation of the thyroid gland. If goiter develops in early childhood, it manifests as endemic cretinism.

Macroscopically, goiter is classified as diffuse, nodular, or mixed. Histologically, it is differentiated into parenchymatous and colloid goiter. Parenchymatous goiter is characterized by a microfollicular Structure with a low colloid content and follicular proliferation. It is typically found in areas of severe endemicity and tends to form functioning parenchymatous nodules. Colloid goiter is composed of follicles. In some cases, the follicles are significantly enlarged, engorged with colloid, lined with flattened follicular epithelium, and exhibit reduced hormonal activity (macrofollicular goiter); in others, the follicles are small (microfollicular goiter). Occasionally, large and small follicles occur together (macro-microfollicular goiter). These forms are frequently accompanied by cystic degeneration, Hemorrhage, and calcification.