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.
Thymus,Gland, Thymus,Glands, Thymus,Thymus Glands
D055633
Immune System Phenomena
The characteristic properties and processes involved in IMMUNITY and an organism's immune response.
Immune System Processes,Immune System Concepts,Immune System Phenomenon,Immune System Process,Concept, Immune System,Concepts, Immune System,Immune System Concept,Phenomena, Immune System,Phenomenon, Immune System,Process, Immune System,Processes, Immune System