The parathyroid glands: An object of universal fascination

The two pairs of parathyroid glands embedded within the posterior surface of the thyroid gland are restricted by a dense capsule around them. These glands comprise two distinct cell populations—parathyroid oxyphil and parathyroid principal cells- pivotal in calcium homeostasis.
Oxyphil cells, whose functions remain elusive, emerge during late puberty, adding a layer of complexity to the parathyroid gland's intricacies. In contrast, principal parathyroid cells undertake a vital role by...

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 intricate framework of the endocrine system encompasses a diverse array of glands, with their target tissues and organs strategically distributed throughout the body. Central to this network are the endocrine glands, specialized structures that lack ducts and release hormones directly into the interstitial fluid. Notably, the hypothalamus, a vital neuroendocrine organ situated in the brain, governs neural functions and serves as a potent source of hormonal regulation. Near the hypothalamus...

The pituitary is a small endocrine organ in the sphenoid bone under the hypothalamus. Primarily, the pituitary in adults has two distinct anatomical and functional regions— the anterior and posterior lobes. During human fetal development, a third pituitary gland region called the pars intermedia atrophies and disappears. However, some of its cells migrate and exist adjacent to the anterior pituitary in adults.

Exocrine glands produce and release a variety of glandular products. Exocrine glands can be classified into serous, mucous, or mixed types based on their secretory products.
Serous glands produce watery secretions rich in digestive enzymes and proteins. The constituent cells of the serous gland have centrally located nuclei and eosinophilic secretory granules in the cytoplasm. The parotid gland is an example of a serous gland. It secretes saliva, which contains enzymes, such as lipases and...

The small, pea-sized pituitary gland is located at the base of the brain. It is crucial in regulating various bodily functions, from growth to reproduction. The gland is divided into the anterior lobe and the posterior lobe. The secretory cell clusters in the pars distalis of the anterior pituitary lobe are controlled by hypothalamic regulators and synthesize six primary hormones.
The most abundantly secreted hormone from the anterior lobe is the growth hormone, which controls overall growth by...