Definition of transient ischemic attack. : a brief episode of cerebral ischemia that is usually characterized by temporary blurring of vision, slurring of speech, numbness, paralysis, or syncope and is often predictive of a serious stroke âabbreviation TIA âcalled also ministroke.
Germinal centers are an important part of the B cell humoral immune response, acting as central factories for the generation of affinity matured B cells specialized in producing improved antibodies that effectively recognize infectious agents, and for the production of durable memory B cells.nce these B cells have stopped proliferating, they migrate to the light zone where they are known as centrocytes, and are subjected to selection by follicular helper T (TFH) cells in the presence of follicular dendritic cells (FDCs).
Lymph nodes. Lymph nodes are body organs (not glands) spread throughout your body. Their function is to filter out all the dead bacteria, viruses, and other dead tissue from the lymphatic fluid and eliminate it from the body.They are also the place where the white blood cells (lymphocytes) spend much of their time.ymph nodes. Lymph nodes are body organs (not glands) spread throughout your body. Their function is to filter out all the dead bacteria, viruses, and other dead tissue from the lymphatic fluid and eliminate it from the body.