| umls-concept:C0040113 | skos:definition | MSH: A single, unpaired primary lymphoid organ situated in the MEDIASTINUM, extending superiorly into the neck to the lower edge of the THYROID GLAND and inferiorly to the fourth costal cartilage. It is necessary for normal development of immunologic function early in life. By puberty, it begins to involute and much of the tissue is replaced by fat.,CSP: single, unpaired primary lymphoid organ situated in the mediastinum; it is necessary for normal development of immunologic function early in life but by puberty it begins to involute and much of the tissue is replaced by fat.,NCI: An organ that is part of the lymphatic system, in which T lymphocytes grow and multiply. The thymus is in the chest behind the breastbone.,NCI: A bi-lobed organ surrounded by a connective tissue capsule. It is located in the upper anterior portion of the chest, behind the sternum. It is composed predominantly of lymphocytes and fewer epithelial cells. Connective tissue septa separate the lobes into lobules. The lobules contain an ou | lld:umls |
