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 NODE, NORMAL HISTOLOGY]. Lymph nodes are small lymphoid organs distributed throughout the body at specific locations and connected to other nearby nodes by lymphatic vessels carrying lymph fluid. A node consists of two main regions cortex (long left arrow) and medullar (arrowhead).The blood vessels and efferent lymphatic channel pass through hilum (bottom arrow). The primary function of lymph node is to respond to non-self antigens and generate antigen-specific soluble antibodies from mature plasma cells.LYMPH NODE, NORMAL HISTOLOGY]. Lymph nodes are small lymphoid organs distributed throughout the body at specific locations and connected to other nearby nodes by lymphatic vessels carrying lymph fluid. A node consists of two main regions cortex (long left arrow) and medullar (arrowhead).