Immune system lymph nodes

Some of the specific components of our immune system are the thymus, spleen, lymph system, lymph nodes, tonsils, liver, appendix (basically a large lymph node), and bone marrow. The thymus coordinates immune... 

Pneumogstis carini pneumonia (PCP), the most common of the opportunistic infections, occurs in more than 80% of AIDS patients (13). Toxoplasmosis, a proto2oan infection of the central nervous system, is activated in AIDS patients when the 004 count drops and severe impairment of ceU-mediated immunity occurs. Typically, patients have a mass lesion(s) in the brain. These mass lesions usually respond well to therapy and can disappear completely. Fungal infections, such as CTyptococcalmeningitis, are extremely common in AIDS patients, and Histop/asma capsulatum appears when ceU-mediated immunity has been destroyed by the HIV vims, leading to widespread infection of the lungs, Hver, spleen, lymph nodes, and bone marrow. AIDS patients are particularly susceptible to bacteremia caused by nontyphoidal strains of Salmonella. Bacteremia may be cleared by using antibiotic therapy. 

NF-kB is also crucial for the proper functioning of the adaptive immune system not only by acting on the immune cells themselves but also by participating in the development and organization of the secondary lymphoid organs (lymph nodes, spleen, and Peyer s patches), in which both B and T lymphocytes undergo maturation and activation. NF-kB proteins have an important role in lymphocyte development and... 

Also, chronic-duration studies have not generally shown adverse effects on organs of the immune system. Routine gross and histopathologic examination of the lymph nodes and thymus of rats, mice, and dogs exposed to endosulfan for 2 years at doses of up to 2.9 mg/kg/day (Hoechst 1989a), 2.51 mg/kg/day (Hoechst 1988b), and 1 mg/kg/day (EMC 1967), respectively, revealed no adverse effects. However, these studies did not assess immune function directly. 

The CB2 receptor has a more limited distribution, being localized predominantly in the immune system. Among the human leukocytes, B lymphocytes express the highest levels of CB2, followed respectively by natural killer cells, monocytes, polymorphonuclear neutrophils, T8 lymphocytes, and T4 lymphocytes. It is also found in the lymph nodes, spleen, tonsils, and thymus (Cabral, 1999). 

There are normally 4000 to 11,000 leukocytes (white blood cells) per microliter of human blood. However, leukocytes act primarily within the tissues those found in the blood are actually in transit. Leukocytes are also found in lymphoid tissues such as the thymus, spleen, and lymph nodes. These cells are referred to as "white" blood cells because they lack hemoglobin and are essentially colorless. Leukocytes are an important component of the immune system. General inflammatory and immune functions of these cells include ... 

Bacterial translocation is defined as the passage of viable indigenous bacteria from the GI tract to extraintesti-nal sites, such as the mesenteric lymph node complex, liver, spleen and bloodstream [183], Three major mechanisms promote bacterial translocation intestinal bacterial overgrowth, deficiencies in host immune defenses and increased permeability or damage to the intestinal mucosal barrier [184], These mechanisms can act in concert to promote synergistically the systemic spread of indigenous translocating bacteria to cause lethal sepsis. 

The pulmonary lymphatic system contributes to the clearance of fluid and protein from the lung tissue interstitium and helps to prevent fluid accumulation in the lungs [108], The lymphatic endothelium allows micron-sized particles (e.g. lipoproteins, plasma proteins, bacteria and immune cells) to pass freely into the lymph fluid [103], After administration of aerosolised ultrafine particles into rats, particles were found in the alveolar walls and in pulmonary lymph nodes [135], which suggests that drainage into the lymph may contribute to the air-to-blood transport of the inhaled particles. 

The response of the body to an invasion by a pathogen involves not only the immnne system bnt other tissnes in which changes in metabolism are essential for a satisfactory response. These inclnde adipose tissne, mnscle and liver, all of which provide precnrsor molecnles (i.e. bnilding materials) for the synthesis of the macromolecnles required for proliferation (Table 17.5). In addition, they provide fuels, the oxidation of which generates ATP for the immune cells, particnlarly to snpport proliferation of the cells in the lymph nodes bnt also for the precnrsor cells in the bone marrow where proliferation increases to prodnce new immune and other cells (Table 17.6). 

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