|
Epithelial Reticular Cell
Epithelial reticular cells, or epithelioreticular cells (ERC), some called thymic epithelial cell (TEC), are a structure in both the cortex and medulla of the thymus. However, histologically, they are more easily identified in the medulla. These cells contain secretory granules which are thought to contain the thymic hormones. There are six different types: Types 1-3 are in the cortex, and types 4-6 are in the medulla. Epithelial reticular cells are the primary cell involved with making sure that no T cell A T cell is a type of lymphocyte. T cells are one of the important white blood cells of the immune system and play a central role in the adaptive immune response. T cells can be distinguished from other lymphocytes by the presence of a T-cell r ...s are allowed to survive which could attack the body's own cells. It does this by expressing a very large proportion of its genome, and expressing as many 'self' proteins on its cell membrane as possible. As the T cells migrate f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cortex (anatomy)
In anatomy and zoology, the cortex (plural cortices) is the outermost (or superficial) layer of an organ. Organs with well-defined cortical layers include kidneys, adrenal glands, ovaries, the thymus, and portions of the brain, including the cerebral cortex, the best-known of all cortices. Etymology The word is of Latin origin and means bark, rind, shell or husk. Notable examples * The renal cortex, between the renal capsule and the renal medulla; assists in ultrafiltration * The adrenal cortex, situated along the perimeter of the adrenal gland; mediates the stress response through the production of various hormones * The thymic cortex, mainly composed of lymphocytes; functions as a site for somatic recombination of T cell receptors, and positive selection * The cerebral cortex, the outer layer of the cerebrum, plays a key role in memory, attention, perceptual awareness, thought, language, and consciousness. * Cortical bone is the hard outer layer of bone; distinct from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thymus
The thymus is a specialized primary lymphoid organ of the immune system. Within the thymus, thymus cell lymphocytes or ''T cells'' mature. T cells are critical to the adaptive immune system, where the body adapts to specific foreign invaders. The thymus is located in the upper front part of the chest, in the anterior superior mediastinum, behind the sternum, and in front of the heart. It is made up of two lobes, each consisting of a central medulla and an outer cortex, surrounded by a capsule. The thymus is made up of immature T cells called thymocytes, as well as lining cells called epithelial cells which help the thymocytes develop. T cells that successfully develop react appropriately with MHC immune receptors of the body (called ''positive selection'') and not against proteins of the body (called ''negative selection''). The thymus is largest and most active during the neonatal and pre-adolescent periods. By the early teens, the thymus begins to decrease in size and a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T Cell
A T cell is a type of lymphocyte. T cells are one of the important white blood cells of the immune system and play a central role in the adaptive immune response. T cells can be distinguished from other lymphocytes by the presence of a T-cell receptor (TCR) on their cell surface. T cells are born from hematopoietic stem cells, found in the bone marrow. Developing T cells then migrate to the thymus gland to develop (or mature). T cells derive their name from the thymus. After migration to the thymus, the precursor cells mature into several distinct types of T cells. T cell differentiation also continues after they have left the thymus. Groups of specific, differentiated T cell subtypes have a variety of important functions in controlling and shaping the immune response. One of these functions is immune-mediated cell death, and it is carried out by two major subtypes: CD8+ "killer" and CD4+ "helper" T cells. (These are named for the presence of the cell surface proteins CD8 or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thymic Nurse Cell
Thymic nurse cells (TNCs) are large epithelial cells found in the cortex of the thymus and also in cortico-medullary junction.Ritter, M. A., C. A. Sauvage, and S. F. Cotmore. "The human thymus microenvironment: in vivo identification of thymic nurse cells and other antigenically-distinct subpopulations of epithelial cells." Immunology 44.3 (1981): 439. They have their own nucleus and are known to internalize thymocytes through extensions of plasma membrane.Hendrix, Tonya M. et al. “Thymic Nurse Cells Exhibit Epithelial Progenitor Phenotype and Create Unique Extra-Cytoplasmic Membrane Space for Thymocyte Selection.” Cellular immunology 261.2 (2010): 81–92. PMC. Web. 6 Feb. 2017 The cell surfaces of TNCs and their cytoplasmic vacuoles express MHC Class I and MHC Class II antigens. The interaction of these antigens with the developing thymocytes determines whether the thymocytes undergo positive or negative selection. Structure and function Thymic nurse cells (TNCs) are a sub-pop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immunology
Immunology is a branch of medicineImmunology for Medical Students, Roderick Nairn, Matthew Helbert, Mosby, 2007 and biology that covers the medical study of immune systems in humans, animals, plants and sapient species. In such we can see there is a difference of human immunology and comparative immunology in veterinary medicine and animal biosciences. Immunology measures, uses charts and differentiate in context in medicine the studies of immunity on cell and molecular level, and the immune system as part of the physiological level as its functioning is of major importance. In the different states of both health, occurring symptoms and diseases; the functioning of the immune system and immunological responses such as autoimmune diseases, allergic hypersensitivities, or in some cases malfunctioning of immune system as for example in immunological disorders or in immune deficiency, and the specific transplant rejection) Immunology has applications in numerous disciplines of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
