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Mononuclear Phagocyte System
In immunology, the mononuclear phagocyte system or mononuclear phagocytic system (MPS) also known as the reticuloendothelial system or macrophage system is a part of the immune system that consists of the phagocytic cells located in reticular connective tissue. The cells are primarily monocytes and macrophages, and they accumulate in lymph nodes and the spleen. The Kupffer cells of the liver and tissue histiocytes are also part of the MPS. The mononuclear phagocyte system and the monocyte macrophage system refer to two different entities, often mistakenly understood as one. "Reticuloendothelial system" is an older term for the mononuclear phagocyte system, but it is used less commonly now, as it is understood that most endothelial cells are not macrophages. The mononuclear phagocyte system is also a somewhat dated concept trying to combine a broad range of cells, and should be used with caution. Cell types and locations The spleen is the second largest unit of the mononuclear ph ... [...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] |
Bone Marrow
Bone marrow is a semi-solid tissue found within the spongy (also known as cancellous) portions of bones. In birds and mammals, bone marrow is the primary site of new blood cell production (or haematopoiesis). It is composed of hematopoietic cells, marrow adipose tissue, and supportive stromal cells. In adult humans, bone marrow is primarily located in the ribs, vertebrae, sternum, and bones of the pelvis. Bone marrow comprises approximately 5% of total body mass in healthy adult humans, such that a man weighing 73 kg (161 lbs) will have around 3.7 kg (8 lbs) of bone marrow. Human marrow produces approximately 500 billion blood cells per day, which join the systemic circulation via permeable vasculature sinusoids within the medullary cavity. All types of hematopoietic cells, including both myeloid and lymphoid lineages, are created in bone marrow; however, lymphoid cells must migrate to other lymphoid organs (e.g. thymus) in order to complete maturation. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mucosa
A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It is mostly of endodermal origin and is continuous with the skin at body openings such as the eyes, eyelids, ears, inside the nose, inside the mouth, lips, the genital areas, the urethral opening and the anus. Some mucous membranes secrete mucus, a thick protective fluid. The function of the membrane is to stop pathogens and dirt from entering the body and to prevent bodily tissues from becoming dehydrated. Structure The mucosa is composed of one or more layers of epithelial cells that secrete mucus, and an underlying lamina propria of loose connective tissue. The type of cells and type of mucus secreted vary from organ to organ and each can differ along a given tract. Mucous membranes line the digestive, respiratory and reproductive trac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skin
Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other cuticle, animal coverings, such as the arthropod exoskeleton, have different cellular differentiation, developmental origin, structure and chemical composition. The adjective cutaneous means "of the skin" (from Latin ''cutis'' 'skin'). In mammals, the skin is an organ (anatomy), organ of the integumentary system made up of multiple layers of ectodermal tissue (biology), tissue and guards the underlying muscles, bones, ligaments, and internal organs. Skin of a different nature exists in amphibians, reptiles, and birds. Skin (including cutaneous and subcutaneous tissues) plays crucial roles in formation, structure, and function of extraskeletal apparatus such as horns of bovids (e.g., cattle) and rhinos, cervids' antlers, giraffids' ossicones, armadillos' osteoderm, and os penis/os clitoris. All mammals have som ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Langerhans Cell
A Langerhans cell (LC) is a tissue-resident macrophage of the skin. These cells contain organelles called Birbeck granules. They are present in all layers of the epidermis and are most prominent in the stratum spinosum. They also occur in the papillary dermis, particularly around blood vessels, as well as in the mucosa of the mouth, foreskin, and vaginal epithelium. They can be found in other tissues, such as lymph nodes, particularly in association with the condition Langerhans cell histiocytosis (LCH). Function In skin infections, the local Langerhans cells take up and process microbial antigens to become fully functional antigen-presenting cells. Generally, tissue-resident macrophages are involved in immune homeostasis and the uptake of apoptotic bodies. However, Langerhans cells can also take on a dendritic cell-like phenotype and migrate to lymph nodes to interact with naive T-cells. Langerhans cells derive from primitive erythro-myeloid progenitors that arise in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Connective Tissues
Connective tissue is one of the four primary types of animal tissue (biology), tissue, along with epithelial tissue, muscle tissue, and nervous tissue. It develops from the mesenchyme derived from the mesoderm the middle embryonic germ layer. Connective tissue is found in between other tissues everywhere in the body, including the nervous system. The three meninges, membranes that envelop the brain and spinal cord are composed of connective tissue. Most types of connective tissue consists of three main components: elastic fiber, elastic and collagen fibers, ground substance, and cell (biology), cells. Blood, and lymph are classed as specialized fluid connective tissues that do not contain fiber. All are immersed in the body water. The cells of connective tissue include fibroblasts, adipocytes, macrophages, mast cells and leucocytes. The term "connective tissue" (in German, ''Bindegewebe'') was introduced in 1830 by Johannes Peter Müller. The tissue was already recognized as a di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Giant Cell
A giant cell (also known as multinucleated giant cell, or multinucleate giant cell) is a mass formed by the union of several distinct cells (usually histiocytes), often forming a granuloma. Although there is typically a focus on the pathological aspects of multinucleate giant cells (MGCs), they also play many important physiological roles. Osteoclasts specifically are invaluable to healthy physiological functions and are key players in the skeletal system. Osteoclasts are frequently classified and discussed separately from other MGCs which are more closely linked with human pathologies. Non-osteoclast MGCs can arise in response to an infection, such as from tuberculosis, herpes, or HIV, or foreign body. These MGCs are cells of monocyte or macrophage lineage fused together. Similar to their monocyte precursors, they are able to phagocytose foreign materials. However, their large size and extensive membrane ruffling make them better equipped to clear up larger particles. They utiliz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macrophage
Macrophages (abbreviated as M φ, MΦ or MP) ( el, large eaters, from Greek ''μακρός'' (') = large, ''φαγεῖν'' (') = to eat) are a type of white blood cell of the immune system that engulfs and digests pathogens, such as cancer cells, microbes, cellular debris, and foreign substances, which do not have proteins that are specific to healthy body cells on their surface. The process is called phagocytosis, which acts to defend the host against infection and injury. These large phagocytes are found in essentially all tissues, where they patrol for potential pathogens by amoeboid movement. They take various forms (with various names) throughout the body (e.g., histiocytes, Kupffer cells, alveolar macrophages, microglia, and others), but all are part of the mononuclear phagocyte system. Besides phagocytosis, they play a critical role in nonspecific defense (innate immunity) and also help initiate specific defense mechanisms (adaptive immunity) by recruiting other immune ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lungs
The lungs are the primary organs of the respiratory system in humans and most other animals, including some snails and a small number of fish. In mammals and most other vertebrates, two lungs are located near the backbone on either side of the heart. Their function in the respiratory system is to extract oxygen from the air and transfer it into the bloodstream, and to release carbon dioxide from the bloodstream into the atmosphere, in a process of gas exchange. Respiration is driven by different muscular systems in different species. Mammals, reptiles and birds use their different muscles to support and foster breathing. In earlier tetrapods, air was driven into the lungs by the pharyngeal muscles via buccal pumping, a mechanism still seen in amphibians. In humans, the main muscle of respiration that drives breathing is the diaphragm. The lungs also provide airflow that makes vocal sounds including human speech possible. Humans have two lungs, one on the left and one on the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulmonary Alveolus
A pulmonary alveolus (plural: alveoli, from Latin ''alveolus'', "little cavity"), also known as an air sac or air space, is one of millions of hollow, distensible cup-shaped cavities in the lungs where oxygen is exchanged for carbon dioxide. Alveoli make up the functional tissue of the mammalian lungs known as the lung parenchyma, which takes up 90 percent of the total lung volume. Alveoli are first located in the respiratory bronchioles that mark the beginning of the respiratory zone. They are located sparsely in these bronchioles, line the walls of the alveolar ducts, and are more numerous in the blind-ended alveolar sacs. The acini are the basic units of respiration, with gas exchange taking place in all the alveoli present. The alveolar membrane is the gas exchange surface, surrounded by a network of capillaries. Across the membrane oxygen is diffused into the capillaries and carbon dioxide released from the capillaries into the alveoli to be breathed out. Alveoli are pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alveolar Macrophage
An alveolar macrophage, pulmonary macrophage, (or dust cell) is a type of macrophage, a professional phagocyte, found in the airways and at the level of the alveoli in the lungs, but separated from their walls. Activity of the alveolar macrophage is relatively high, because they are located at one of the major boundaries between the body and the outside world. They are responsible for removing particles such as dust or microorganisms from the respiratory surfaces. Alveolar macrophages are frequently seen to contain granules of exogenous material such as particulate carbon that they have picked up from respiratory surfaces. Such black granules may be especially common in smoker's lungs or long-term city dwellers. The alveolar macrophage is the third cell type in the alveolus, the others are the type I and type II pneumocytes. Comparison of pigmented pulmonary macrophages Function Alveolar macrophages are phagocytes that play a critical role in homeostasis, host defen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lymph Node
A lymph node, or lymph gland, is a kidney-shaped organ of the lymphatic system and the adaptive immune system. A large number of lymph nodes are linked throughout the body by the lymphatic vessels. They are major sites of lymphocytes that include B and T cells. Lymph nodes are important for the proper functioning of the immune system, acting as filters for foreign particles including cancer cells, but have no detoxification function. In the lymphatic system a lymph node is a secondary lymphoid organ. A lymph node is enclosed in a fibrous capsule and is made up of an outer cortex and an inner medulla. Lymph nodes become inflamed or enlarged in various diseases, which may range from trivial throat infections to life-threatening cancers. The condition of lymph nodes is very important in cancer staging, which decides the treatment to be used and determines the prognosis. Lymphadenopathy refers to glands that are enlarged or swollen. When inflamed or enlarged, lymph nodes can be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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