Epithelial hyperplasia is responsible for the compensatory enlargement of remaining thyroid lobe after thyroidectomy

Cell division and enlargement are processes that require precise control. The control ensures that cell division cannot proceed unless the cell has grown to a specific size. A spherical, dividing cell requires an approximately 1.6X increase in its surface area to double its volume. The secretory pathway also has a significant role in cell membrane enlargement. Secretory vesicles that bud off from the Golgi apparatus and later fuse with the plasma membrane during exocytosis are a major source of...

The cerebral cortex, a critical structure of the brain, is intricately divided into two hemispheres, each consisting of four distinct lobes: occipital, temporal, frontal, and parietal. These lobes function cooperatively to regulate various cognitive and sensory functions, forming the basis of our complex neural capabilities.
Frontal lobe
The frontal lobes, located behind the forehead, are the command center of our brain, controlling personality, intelligence, and voluntary muscle movements....

The thyroid gland is a small, butterfly-shaped gland located in the neck and covers the anterior surface of the trachea. The gland has two lateral lobes connected by a thin tissue mass called the isthmus. Internally, each lobe comprises many small spherical structures known as thyroid follicles, surrounded by a network of blood vessels.
The follicles have a central cavity lined by simple cuboidal to squamous epithelial cells called follicular cells. These cells produce the glycoprotein...

The thyroid hormone (TH) plays a pivotal role in the intricate orchestration of physiological processes, exerting profound effects on development, metabolism, and homeostasis throughout different life stages.
TH is indispensable for the normal development and maturation of the skeletal, muscular, and nervous systems during fetal and childhood growth. It facilitates bone mineral turnover and regulates protein synthesis in developing tissues, contributing significantly to overall growth and...

Low blood levels of the thyroid hormones — triiodothyronine (T3) and thyroxine (T4) — signal the hypothalamus to release the thyrotropin-releasing hormone (TRH). TRH then reaches the pituitary gland and stimulates the release of thyroid-stimulating hormone(TSH) into the bloodstream.
Upon reaching the thyroid gland, TSH stimulates the follicular cells' active uptake of iodide ions from the blood. The ions diffuse to the apical surface of the cells and are oxidized to iodine. The...

Epithelial tissues are large sheets of cells covering all of the surfaces of the body. These surfaces can be internal or external, for example, skin, airways, the digestive tract, the urinary system, and the reproductive system. Hollow organs and body cavities that do not connect to the body's exterior, including blood vessels and serous membranes, are lined by epithelial tissue known as the endothelium.
Epithelial tissues provide the body's first line of protection from physical,...