Adrenal gland
A number of endocrine diseases involve dysfunctions of the adrenal gland. Overproduction of cortisol leads to Cushing's syndrome, whereas insufficient production is associated with Addison's disease. Congenital adrenal hyperplasia is a genetic disease produced by dysregulation of endocrine control mechanisms. A variety of tumors can arise from adrenal tissue and are commonly found in medical imaging when searching for other diseases.
The adrenal glands are located on both sides of the body in the retroperitoneum, above and slightly medial to the kidneys. In humans, the right adrenal gland is pyramidal in shape, whereas the left is semilunar or crescent shaped and somewhat larger. The adrenal glands measure approximately 3 cm in width, 5.0 cm in length, and up to 1.0 cm in thickness. Their combined weight in an adult human ranges from 7 to 10 grams. The glands are yellowish in colour.
Eugène Gley
In 1891 Gley was the first to discover the importance of the parathyroid glands, which are four (or more) small endocrine glands lying close or embedded in the posterior surface of the thyroid gland. These glands had been recently discovered as an anatomical entity in 1880, however their importance was not understood at the time. Gley realized that the cause of tetany after thyroid operations was the inadvertent destruction of the parathyroid glands. He demonstrated this by removing the parathyroid glands from laboratory animals and witnessing their deaths from tetany. Because of his discovery, parathyroid glands have sometimes been referred to as "Gley's glands".