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Because T cells recognize only fragmented antigens displayed on cell surfaces, antigen processing must occur before the antigen fragment can be recognized by a T-cell receptor. Specifically, the fragment, bound to the major histocompatibility complex (MHC) , is transported to the surface of the antigen-presenting cell , a process known as ...
Antigen presentation stimulates immature T cells to become either mature "cytotoxic" CD8+ cells or mature "helper" CD4+ cells. An antigen-presenting cell (APC) or accessory cell is a cell that displays an antigen bound by major histocompatibility complex (MHC) proteins on its surface; this process is known as antigen presentation.
Langerhans' cells are particular type of dendritic cells present in non lymphoid tissues together with interstitial cells. When these cells (in an immature state) come in contact with antigenic cells or disease causing viruses etc. these cells produce an inflammatory stimulus and start antigen processing and move toward lymph nodes where these ...
MHC class I molecules are one of two primary classes of major histocompatibility complex (MHC) molecules (the other being MHC class II) and are found on the cell surface of all nucleated cells in the bodies of vertebrates. [1] [2] They also occur on platelets, but not on red blood cells.
It has low nucleated cell counts (less than 500 to 1000 per microliter) and the primary cell types are mononuclear cells: macrophages, lymphocytes and mesothelial cells. For instance, an ultrafiltrate of blood plasma is transudate. It results from increased fluid pressures or diminished colloid oncotic forces in the plasma.
Thoracentesis / ˌ θ ɔː r ə s ɪ n ˈ t iː s ɪ s /, also known as thoracocentesis (from Greek θώραξ (thōrax, GEN thōrakos) 'chest, thorax' and κέντησις (kentēsis) 'pricking, puncture'), pleural tap, needle thoracostomy, or needle decompression (often used term), is an invasive medical procedure to remove fluid or air from the pleural space for diagnostic or therapeutic ...
The transcellular fluid is the portion of total body fluid that is formed by the secretory activity of epithelial cells and is contained within specialized epithelial-lined compartments. Fluid does not normally collect in larger amounts in these spaces, [6] [7] and any significant fluid collection in these spaces is physiologically ...
Diffusion occurs through the walls of the vessels due to a concentration gradient, allowing the necessary exchange of ions, molecules, or blood cells. The permeability of a capillary wall is determined by the type of capillary and the surface of the endothelial cells. A continuous, tightly spaced endothelial cell lining only permits the ...