Lymph nodes anatomic locations

We now turn to an anatomical description of lymph nodes. The lymph node is surrounded by a thick, fibrous capsule and is subdivided into compartments by trabeculae. Inside the capsule is the subcapsular or marginal sinus, which forms the entry point of lymphatic fluid into the node, via the afferent vessel. The lymph node cortex, which lies beneath the subcapsular sinus, is the location of the primary and secondary lymphoid follicles. The primary follicles are comprised of B-lymphocytes. An immune response stimulates B-cells to replicate and differentiate, converting the primary follicle into a secondary follicle or germinal center, surrounded by a zone of small lymphocytes. The paracortex surrounds the germinal centers and primary follicles and contains mostly T-lymphocytes. The medulla is composed of medullary cords, consisting of macrophages and plasma cells, and medullary sinuses. The medullary vessels include the arteries and veins, and the afferent and efferent lymphatic vessels, respectively, deliver the lymphatic fluid into and out of the lymph node. 

Chemoattractants and their receptors precisely orchestrate the primary migration of developing lymphocytes into and out of secondary lymphoid organs (SLOs) and the organization of second immune anatomic strucmre within the SLO such as B cell follicles and germinal centers (1-3). Many draining lymph nodes (LN) are located at sites superficially under the skin. They are well-compartmentalized structures with specific microenvironments for lymphocytes. Many lymphocytes reside only temporarily within lymph nodes since they continually recirculate between the blood and the lymph. Most human and mouse lymphocytes enter... 

Other tissues should not be accepted for quantification. Samples with pleural thickening, pleural plaque and tumour tissue contain few particles and will result in false-negative counts. The particle content of lymph nodes may be influenced by their anatomical location. The parietal pleura is a very heterogeneous phase. Anatomical structures resorbing pleural fluid from the pleural space may trap and concentrate particles and fibers in localised areas called black spots because of their pigmentation (Boutin et al. 1996 Mitchev et al. 2002). All these samples are not suitable for routine purposes, but maybe used for research purposes, e.g. when studying the migration of fibers in the human body. 

The typical mesothelioma found at autopsy is a firm and hard mass of whitish or grayish tissue that envelops adjacent anatomical structures, including the lung and the mediastinal and hilar vessels. In most cases, the pleural space is obliterated. Gelatinous material is often present in small cysts that are located inside the tumor. Most tumors will spread diffusely, but in some cases they might include areas that are well circumscribed. The tumor starts on the parietal surface of the pleura but soon reaches the visceral pleura. Consequently, tumor deposits can be found on both the parietal and the visceral pleura. Approximately 50% of all patients with mesothelioma will have distant metastases. Lymph nodes are... 

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