| Name: | thymus |
|---|---|
| Synonyms: | |
| Definition: | Paired organ where maturation of T-lymphocytes occurs. The adult thymus located on the dorsomedial aspect of the branchial cavity above the third pharyngeal cartilage. The thymus undergoes a period of rapid growth beginning at about the third week and continuing for several more weeks. Accompanying this growth is a dramatic change in the shape of the thymus. It is ovoid initially and then starts to grow dorsally along the skull, forming a characteristic protrusion. During this growth period the adult pattern of rag1-positive cortex and rag1-negative medulla becomes established. The protrusions diminish with age and the thymus gradually shrinks; at two years, the thymus is again confined to the pharynx with minimal if any protrusion. |
| Ontology: | Anatomy Ontology [ZFA:0001078] |
| Name: | macrophage |
|---|---|
| Synonyms: | histiocyte |
| Definition: | A mononuclear phagocyte present in variety of tissues, typically differentiated from monocytes, capable of phagocytosing a variety of extracellular particulate material, including immune complexes, microorganisms, and dead cells. |
| Ontology: | Anatomy Ontology [ZFA:0009141] |