| lymph node | <anatomy> Small bean-shaped organ made up of a loose meshwork of reticular tissue in which are enmeshed large numbers of lymphocytes, macrophages and accessory cells located along the lymphatic system. Recirculating lymphocytes leave the blood through the specialised high endothelial venules of the lymph node and pass through the node before being returned to the blood through the lymphatic system. Because the lymph nodes act as drainage points for tissue fluids, they are also regions in which foreign antigens present in the tissue fluid are most likely to begin to elicit an immune response. Nodes filter out bacteria or cancer cells that may travel through the lymphatic system. Synonym: lymph glands. (14 Oct 1997) |
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| lymph node excision | Surgical excision of one or more lymph nodes. Its most common use is in cancer surgery. (12 Dec 1998) |
| lymph node of ligamentum arteriosum | A lymph node of the anterior mediastinal group located adjacent to the ligamentum arteriosum. Synonym: nodus ligamenti arteriosi, lymph node of ligamentum arteriosum. (05 Mar 2000) |
| lymph node permeability factor | A substance, released by lymphocytes when stimulated or damaged, that increases capillary permeability and the accumulation of mononuclear cells. (05 Mar 2000) |
| arteria articularis azygos | <anatomy, artery> Origin, popliteal; distribution, synovial membrane and cruciate ligaments of knee joint. Synonym: arteria genus media, arteria articularis azygos. (05 Mar 2000) |
| azygos | 1. An unpaired (azygous) anatomical structure. Synonym: azygos vein. Origin: G. A-priv. + zygon, a yoke (05 Mar 2000) |
| azygos artery of vagina | One of two artery's that run longitudinally in the midline on the anterior and posterior aspects of the vagina; they take origin from the uterine artery. (05 Mar 2000) |
| azygos continuation | (of the inferior vena cava), a congenital anomaly in which the infrahepatic portion of the vena cava fails to form, and venous drainage of the lower body is maintained through a persistent right supracardinal vein, which becomes a large azygos vein. (05 Mar 2000) |
| azygos continuation of interrupted ivc | <radiology> IVC interrupted, hepatic portion absent, joins azygos or hemiazygos, hepatic veins empty directly into RA, associated with polysplenia (12 Dec 1998) |
| azygos fissure | The four-layered pleural fold that separates the lobus azygos from the rest of the right upper lobe of the lung, seen as an oblique line pointing downward toward the mediastinal shadow in the upper right lung field on a chest radiograph. (05 Mar 2000) |
| azygos lobe of lung | A small accessory lobe sometimes found on the apex of the right lung; separated from the rest of the upper lobe by a deep groove lodging the azygos vein. Synonym: lobus azygos. (05 Mar 2000) |
| azygos pseudo-lobe | <radiology> Not a true lobe, does not have separate broncus or vasculature, due to invagination of azygos vein into RUL, no clinical significance (12 Dec 1998) |
| vena azygos | <anatomy, vein> A vein which arises from the right ascending lumbar vein or the vena cava, enters the thorax through the aortic orifice in the diaphragm, and terminates in the superior vena cava. (12 Dec 1998) |
| vena azygos major | <anatomy, vein> A vein which arises from the right ascending lumbar vein or the vena cava, enters the thorax through the aortic orifice in the diaphragm, and terminates in the superior vena cava. (12 Dec 1998) |
| vena azygos minor inferior | <anatomy, vein> Formed by the merger of the left ascending lumbar vein with the left subcostal vein or a communication from the inferior vena cava, it pierces the left crus of the diaphragm, ascends along the left side of the bodies of the lower thoracic vertebrae, opposite the eighth vertebra, crosses the midline behind the aorta, thoracic duct, and oesophagus, and empties into the azygos vein, sometimes in common with the accessory hemiazygos vein. Synonym: vena hemiazygos, vena azygos minor inferior. (05 Mar 2000) |