|
Immunity (biology)
In biology, immunity is the capability of multicellular organisms to resist harmful microorganisms. Immunity involves both specific and nonspecific components. The nonspecific components act as barriers or eliminators of a wide range of pathogens irrespective of their antigenic make-up. Other components of the immune system adapt themselves to each new disease encountered and can generate pathogen-specific immunity. Immunity is a complex biological system that can recognize and tolerate whatever belongs to the self, and to recognize and reject what is foreign (non-self). Innate and adaptive Innate Immunity First off, the immune system is a system in the body of animals that enables animals to avoid or limit many infections caused by pathogens. Pathogens are disease causing agents, causing a wide range of illnesses. As for Diseases it's when structure of an organism is negatively affected other than external injury. Both diseases and pathogens affect the immune system causing ill ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multicellular Organisms
A multicellular organism is an organism that consists of more than one cell, in contrast to unicellular organism. All species of animals, land plants and most fungi are multicellular, as are many algae, whereas a few organisms are partially uni- and partially multicellular, like slime molds and social amoebae such as the genus '' Dictyostelium''. Multicellular organisms arise in various ways, for example by cell division or by aggregation of many single cells. Colonial organisms are the result of many identical individuals joining together to form a colony. However, it can often be hard to separate colonial protists from true multicellular organisms, because the two concepts are not distinct; colonial protists have been dubbed "pluricellular" rather than "multicellular". There are also multinucleate though technically unicellular organisms that are macroscopic, such as the xenophyophorea that can reach 20 cm. Evolutionary history Occurrence Multicellularity has ev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lymphocytes
A lymphocyte is a type of white blood cell (leukocyte) in the immune system of most vertebrates. Lymphocytes include natural killer cells (which function in cell-mediated, cytotoxic innate immunity), T cells (for cell-mediated, cytotoxic adaptive immunity), and B cells (for humoral, antibody-driven adaptive immunity). They are the main type of cell found in lymph, which prompted the name "lymphocyte". Lymphocytes make up between 18% and 42% of circulating white blood cells. Types The three major types of lymphocyte are T cells, B cells and natural killer (NK) cells. Lymphocytes can be identified by their large nucleus. T cells and B cells T cells ( thymus cells) and B cells ( bone marrow- or bursa-derived cells) are the major cellular components of the adaptive immune response. T cells are involved in cell-mediated immunity, whereas B cells are primarily responsible for humoral immunity (relating to antibodies). The function of T cells and B cells is to recogn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vaccine
A vaccine is a biological preparation that provides active acquired immunity to a particular infectious or malignant disease. The safety and effectiveness of vaccines has been widely studied and verified. A vaccine typically contains an agent that resembles a disease-causing microorganism and is often made from weakened or killed forms of the microbe, its toxins, or one of its surface proteins. The agent stimulates the body's to recognize the agent as a threat, destroy it, and to further recognize and destroy any of the microorganisms associated with that agent that it may encounter in the future. Vaccines can be prophylactic (to pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toxoid
A toxoid is an inactivated toxin (usually an exotoxin) whose toxicity has been suppressed either by chemical ( formalin) or heat treatment, while other properties, typically immunogenicity, are maintained. Toxins are secreted by bacteria, whereas toxoids are altered form of toxins; toxoids are ''not'' secreted by bacteria. Thus, when used during vaccination, an immune response is mounted and immunological memory is formed against the molecular markers of the toxoid without resulting in toxin-induced illness. Such a preparation is also known as an anatoxin. There are toxoids for prevention of diphtheria, tetanus and botulism. Toxoids are used as vaccines because they induce an immune response to the original toxin or increase the response to another antigen since the toxoid markers and toxin markers are preserved. For example, the tetanus toxoid is derived from the tetanospasmin produced by '' Clostridium tetani''. The latter causes tetanus and is vaccinated against by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mithridates VI Of Pontus
Mithridates or Mithradates VI Eupator ( grc-gre, Μιθραδάτης; 135–63 BC) was ruler of the Kingdom of Pontus in northern Anatolia from 120 to 63 BC, and one of the Roman Republic's most formidable and determined opponents. He was an effective, ambitious and ruthless ruler who sought to dominate Asia Minor and the Black Sea region, waging several hard-fought but ultimately unsuccessful wars (the Mithridatic Wars) to break Roman dominion over Asia and the Hellenic world. He has been called the greatest ruler of the Kingdom of Pontus. He cultivated an immunity to poisons by regularly ingesting sub-lethal doses; this practice, now called mithridatism, is named after him. After his death he became known as Mithridates the Great. Etymology ''Mithridates'' is the Greek attestation of the Persian name ''Mihrdāt'', meaning "given by Mithra", the name of the ancient Iranian sun god. The name itself is derived from Old Iranian ''Miθra-dāta-''. Ancestry, family and ear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Athens
Athens ( ; el, Αθήνα, Athína ; grc, Ἀθῆναι, Athênai (pl.) ) is both the capital city, capital and List of cities and towns in Greece, largest city of Greece. With a population close to four million, it is also the seventh List of urban areas in the European Union, largest city in the European Union. Athens dominates and is the capital of the Attica (region), Attica region and is one of the List of oldest continuously inhabited cities, world's oldest cities, with its recorded history spanning over 3,400 years and its earliest human presence beginning somewhere between the 11th and 7th millennia BC. Classical Athens was a powerful Greek city-state, city-state. It was a centre for the arts, learning and philosophy, and the home of Plato's Platonic Academy, Academy and Aristotle's Lyceum (classical), Lyceum. It is widely referred to as the cradle of civilization, cradle of Western culture, Western civilization and the democracy#History, birthplace of democracy, larg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thucydides
Thucydides (; grc, , }; BC) was an Athenian historian and general. His '' History of the Peloponnesian War'' recounts the fifth-century BC war between Sparta and Athens until the year 411 BC. Thucydides has been dubbed the father of " scientific history" by those who accept his claims to have applied strict standards of impartiality and evidence-gathering and analysis of cause and effect, without reference to intervention by the gods, as outlined in his introduction to his work. He also has been called the father of the school of political realism, which views the political behavior of individuals and the subsequent outcomes of relations between states as ultimately mediated by, and constructed upon, fear and self-interest. His text is still studied at universities and military colleges worldwide. The Melian dialogue is regarded as a seminal work of international relations theory, while his version of Pericles' Funeral Oration is widely studied by political theorists, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Four Humors
Humorism, the humoral theory, or humoralism, was a system of medicine detailing a supposed makeup and workings of the human body, adopted by Ancient Greek and Roman physicians and philosophers. Humorism began to fall out of favor in the 1850s with the advent of germ theory, which was able to show that many diseases previously thought to be humoral were in fact caused by microbes. Origin The concept of "humors" (chemical systems regulating human behaviour) became more prominent from the writing of medical theorist Alcmaeon of Croton (c. 540–500 BC). His list of humors was longer and included fundamental elements described by Empedocles, such as water, air, earth, fire, etc.. The concept of "humors" may have origins in Ancient Egyptian medicine, or Mesopotamia, though it was not systemized until ancient Greek thinkers. The word ''humor'' is a translation of Greek χυμός, ''chymos'' (literally juice or sap, metaphorically flavor). Ancient Indian Ayurveda medicine had deve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hippocrates
Hippocrates of Kos (; grc-gre, Ἱπποκράτης ὁ Κῷος, Hippokrátēs ho Kôios; ), also known as Hippocrates II, was a Greek physician of the classical period who is considered one of the most outstanding figures in the history of medicine. He is traditionally referred to as the "Father of Medicine" in recognition of his lasting contributions to the field, such as the use of prognosis and clinical observation, the systematic categorization of diseases, or the formulation of humoral theory. The Hippocratic school of medicine revolutionized ancient Greek medicine, establishing it as a discipline distinct from other fields with which it had traditionally been associated ( theurgy and philosophy), thus establishing medicine as a profession. However, the achievements of the writers of the Hippocratic Corpus, the practitioners of Hippocratic medicine, and the actions of Hippocrates himself were often conflated; thus very little is known about what Hippocrates actual ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theurgy
Theurgy (; ) describes the practice of rituals, sometimes seen as magical in nature, performed with the intention of invoking the action or evoking the presence of one or more deities, especially with the goal of achieving henosis (uniting with the divine) and perfecting oneself. Definitions *Proclus (c. 480): theurgy is "a power higher than all human wisdom embracing the blessings of divination, the purifying powers of initiation and in a word all the operations of divine possession" * Keith Thomas: "Spiritual magic or theurgy was based on the idea that one could reach God in an ascent up the scale of creation made possible by a rigorous course of prayer, fasting and devotional preparation." *Pierre A. Riffard: "Theurgy is a type of magic. It consists of a set of magical practices performed to evoke beneficent spirits in order to see them or know them or in order to influence them, for instance by forcing them to animate a statue, to inhabit a human being (such as a medi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cholera Art
Cholera is an infection of the small intestine by some strains of the bacterium '' Vibrio cholerae''. Symptoms may range from none, to mild, to severe. The classic symptom is large amounts of watery diarrhea that lasts a few days. Vomiting and muscle cramps may also occur. Diarrhea can be so severe that it leads within hours to severe dehydration and electrolyte imbalance. This may result in sunken eyes, cold skin, decreased skin elasticity, and wrinkling of the hands and feet. Dehydration can cause the skin to turn bluish. Symptoms start two hours to five days after exposure. Cholera is caused by a number of types of ''Vibrio cholerae'', with some types producing more severe disease than others. It is spread mostly by unsafe water and unsafe food that has been contaminated with human feces containing the bacteria. Undercooked shellfish is a common source. Humans are the only known host for the bacteria. Risk factors for the disease include poor sanitation, not en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immunity
Immunity may refer to: Medicine * Immunity (medical), resistance of an organism to infection or disease * ''Immunity'' (journal), a scientific journal published by Cell Press Biology * Immune system Engineering * Radiofrequence immunity describes how well an electronic circuit is protected against electromagnetic interference Law *Legal immunity, the concept of a person or entity being immune from legal liability due to a special status ** Absolute immunity, a type of immunity for government officials that confers total immunity when acting in the course of their duties ** Amnesty law, a law that provides immunity for past crimes ** Charitable immunity, immunity from liability granted to charities in many countries from the 19th century to the mid-20th century **Diplomatic immunity, agreement between sovereign governments to exclude diplomats from local laws **Immunity from prosecution (international law), exclusion of governments or their officials from prosecution under int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
