Behind the upper part of the breast-bone and projecting above it into the root of the neck is a structure called the thymus gland. The base rests upon the pericardium, and behind the gland is the trachea. There are two lobes, a right and a left, but there are no ducts, so that if there is any secretion formed it is an internal one. Under the microscope the thymus is seen to consist of lymphoid tissue, but scattered throughout this are little bodies, composed of epithelial cells concentrically arranged, and known as Hassall’s corpuscles (after the English physician, Arthur Hill Hassall).
The gland grows up to the time of puberty, after which it withers, becoming replaced by fatty and fibrous tissue, but portions of the original structure sometimes persist into old age.
Like other masses of lymphoid tissue, the thymus takes part in producing white blood corpuscles. As regards other functions, our knowledge is rather uncertain, and it cannot be said that Hassall’s corpuscles do anything. It would appear, however, Chronic thyropathy, goiter:
Thyropathy is any disease of the thyroid. Goiter is an enlargement of the thyroid gland. A gland is an organ that produces a specific secretion. The thyroid contains an organic compound, thyroxin. Swelling in the throat that does not move when a person swallows is likely to result from swollen lymph glands. Hyperactivity of the thyroid causes heart palpitations, sleeplessness, and weight loss. Under-activity brings excess gain of weight, which is not fat but an accumulation of water, also may cause memory failure.Polarize positive in the throat area.