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Tissue Hydration
Tissue hydration is the process of absorbing and retaining water in biological tissues. Plants Land plants maintain adequate tissue hydration by means of an outer waterproof layer. In soft or green tissues, this is usually a waxy cuticle over the outer epidermis. In older, woody tissues, waterproofing chemicals are present in the secondary cell wall that limit or inhibit the flow of water. Vascular plants also possess an internal vascular system that distributes fluids throughout the plant. Some xerophytes, such as cacti and other desert plants, have mucilage in their tissues. This is a sticky substance that holds water within the plant, reducing the rate of dehydration. Some seeds and spores remain dormant until adequate moisture is present, at which time the seed or spore begins to germinate. Animals Animals maintain adequate tissue hydration by means of (1) an outer skin, shell, or cuticle; (2) a fluid-filled coelom cavity; and (3) a circulatory system. Hydration of fat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water
Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a solvent). It is vital for all known forms of life, despite not providing food, energy or organic micronutrients. Its chemical formula, H2O, indicates that each of its molecules contains one oxygen and two hydrogen atoms, connected by covalent bonds. The hydrogen atoms are attached to the oxygen atom at an angle of 104.45°. "Water" is also the name of the liquid state of H2O at standard temperature and pressure. A number of natural states of water exist. It forms precipitation in the form of rain and aerosols in the form of fog. Clouds consist of suspended droplets of water and ice, its solid state. When finely divided, crystalline ice may precipitate in the form of snow. The gaseous state of water is steam or water vapor. Water co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exoskeleton
An exoskeleton (from Greek ''éxō'' "outer" and ''skeletós'' "skeleton") is an external skeleton that supports and protects an animal's body, in contrast to an internal skeleton (endoskeleton) in for example, a human. In usage, some of the larger kinds of exoskeletons are known as " shells". Examples of exoskeletons within animals include the arthropod exoskeleton shared by chelicerates, myriapods, crustaceans, and insects, as well as the shell of certain sponges and the mollusc shell shared by snails, clams, tusk shells, chitons and nautilus. Some animals, such as the turtle, have both an endoskeleton and an exoskeleton. Role Exoskeletons contain rigid and resistant components that fulfill a set of functional roles in many animals including protection, excretion, sensing, support, feeding and acting as a barrier against desiccation in terrestrial organisms. Exoskeletons have a role in defense from pests and predators, support and in providing an attachment framework f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osmoregulation
Osmoregulation is the active regulation of the osmotic pressure of an organism's body fluids, detected by osmoreceptors, to maintain the homeostasis of the organism's water content; that is, it maintains the fluid balance and the concentration of electrolytes (salts in solution which in this case is represented by body fluid) to keep the body fluids from becoming too diluted or concentrated. Osmotic pressure is a measure of the tendency of water to move into one solution from another by osmosis. The higher the osmotic pressure of a solution, the more water tends to move into it. Pressure must be exerted on the hypertonic side of a selectively permeable membrane to prevent diffusion of water by osmosis from the side containing pure water. Although there may be hourly and daily variations in osmotic balance, an animal is generally in an osmotic steady state over the long term. Organisms in aquatic and terrestrial environments must maintain the right concentration of solutes and amo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptobiosis
Cryptobiosis or anabiosis is a metabolic state of life entered by an organism in response to adverse environmental conditions such as desiccation, freezing, and oxygen deficiency. In the cryptobiotic state, all measurable metabolic processes stop, preventing reproduction, development, and repair. When environmental conditions return to being hospitable, the organism will return to its metabolic state of life as it was prior to the cryptobiosis. Forms Anhydrobiosis Anhydrobiosis is the most studied form of cryptobiosis and occurs in situations of extreme desiccation. The term ''anhydrobiosis'' derives from the Greek for "life without water" and is most commonly used for the desiccation tolerance observed in certain invertebrate animals such as bdelloid rotifers, tardigrades, brine shrimp, nematodes, and at least one insect, a species of chironomid (''Polypedilum vanderplanki''). However, other life forms exhibit desiccation tolerance. These include the resurrection plant ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Desiccation
Desiccation () is the state of extreme dryness, or the process of extreme drying. A desiccant is a hygroscopic (attracts and holds water) substance that induces or sustains such a state in its local vicinity in a moderately sealed container. Industry Desiccation is widely employed in the oil and gas industry. These materials are obtained in a hydrated state, but the water content leads to corrosion or is incompatible with downstream processing. Removal of water is achieved by cryogenic condensation, absorption into glycols, and absorption onto desiccants such as silica gel. Laboratory A desiccator is a heavy glass or plastic container, now somewhat antiquated, used in practical chemistry for drying or keeping small amounts of materials very dry. The material is placed on a shelf, and a drying agent or ''desiccant'', such as dry silica gel or anhydrous sodium hydroxide, is placed below the shelf. Often some sort of humidity indicator is included in the desiccator to show, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluid Replacement
Fluid replacement or fluid resuscitation is the medical practice of replenishing bodily fluid lost through sweating, bleeding, fluid shifts or other pathologic processes. Fluids can be replaced with oral rehydration therapy (drinking), intravenous therapy, rectally such as with a Murphy drip, or by ''hypodermoclysis'', the direct injection of fluid into the subcutaneous tissue. Fluids administered by the oral and hypodermic routes are absorbed more slowly than those given intravenously. By mouth Oral rehydration therapy (ORT) is a simple treatment for dehydration associated with diarrhea, particularly gastroenteritis/gastroenteropathy, such as that caused by cholera or rotavirus. ORT consists of a solution of salts and sugars which is taken by mouth. For most mild to moderate dehydration in children, the preferable treatment in an emergency department is ORT over intravenous replacement of fluid., which cites: * It is used around the world, but is most important in the developing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrational Fluid
Oral rehydration therapy (ORT) is a type of fluid replacement used to prevent and treat dehydration, especially due to diarrhea. It involves drinking water with modest amounts of sugar and salts, specifically sodium and potassium. Oral rehydration therapy can also be given by a nasogastric tube. Therapy should routinely include the use of zinc supplements. Use of oral rehydration therapy has been estimated to decrease the risk of death from diarrhea by up to 93%. Side effects may include vomiting, high blood sodium, or high blood potassium. If vomiting occurs, it is recommended that use be paused for 10 minutes and then gradually restarted. The recommended formulation includes sodium chloride, sodium citrate, potassium chloride, and glucose. Glucose may be replaced by sucrose and sodium citrate may be replaced by sodium bicarbonate, if not available. It works as glucose increases the uptake of sodium and thus water by the intestines. A number of other formulations are also avail ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dehydration
In physiology, dehydration is a lack of total body water, with an accompanying disruption of metabolic processes. It occurs when free water loss exceeds free water intake, usually due to exercise, disease, or high environmental temperature. Mild dehydration can also be caused by immersion diuresis, which may increase risk of decompression sickness in divers. Most people can tolerate a 3-4% decrease in total body water without difficulty or adverse health effects. A 5-8% decrease can cause fatigue and dizziness. Loss of over ten percent of total body water can cause physical and mental deterioration, accompanied by severe thirst. Death occurs at a loss of between fifteen and twenty-five percent of the body water.Ashcroft F, Life Without Water in Life at the Extremes. Berkeley and Los Angeles, 2000, 134-138. Mild dehydration is characterized by thirst and general discomfort and is usually resolved with oral rehydration. Dehydration can cause hypernatremia (high levels of sodium ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circulatory System
The blood circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the entire body of a human or other vertebrate. It includes the cardiovascular system, or vascular system, that consists of the heart and blood vessels (from Greek ''kardia'' meaning ''heart'', and from Latin ''vascula'' meaning ''vessels''). The circulatory system has two divisions, a systemic circulation or circuit, and a pulmonary circulation or circuit. Some sources use the terms ''cardiovascular system'' and ''vascular system'' interchangeably with the ''circulatory system''. The network of blood vessels are the great vessels of the heart including large elastic arteries, and large veins; other arteries, smaller arterioles, capillaries that join with venules (small veins), and other veins. The Closed circulatory system, circulatory system is closed in vertebrates, which means that the blood never leaves the network of blood vessels. Some in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coelom
The coelom (or celom) is the main body cavity in most animals and is positioned inside the body to surround and contain the digestive tract and other organs. In some animals, it is lined with mesothelium. In other animals, such as molluscs, it remains undifferentiated. In the past, and for practical purposes, coelom characteristics have been used to classify bilaterian animal phyla into informal groups. Etymology The term ''coelom'' derives from the Ancient Greek word (), meaning 'cavity'. Structure Development The coelom is the mesodermally lined cavity between the gut and the outer body wall. During the development of the embryo, coelom formation begins in the gastrulation stage. The developing digestive tube of an embryo forms as a blind pouch called the archenteron. In Protostomes, the coelom forms by a process known as schizocoely. The archenteron initially forms, and the mesoderm splits into two layers: the first attaches to the body wall or ectoderm, forming ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cuticle
A cuticle (), or cuticula, is any of a variety of tough but flexible, non-mineral outer coverings of an organism, or parts of an organism, that provide protection. Various types of "cuticle" are non- homologous, differing in their origin, structure, function, and chemical composition. Human anatomy In human anatomy, "cuticle" can refer to several structures, but it is used in general parlance, and even by medical professionals, to refer to the thickened layer of skin surrounding fingernails and toenails (the eponychium), and to refer to the superficial layer of overlapping cells covering the hair shaft ( cuticula pili), consisting of dead cells, that locks the hair into its follicle. It can also be used as a synonym for the epidermis, the outer layer of skin. Cuticle of invertebrates In zoology, the invertebrate cuticle or cuticula is a multi-layered structure outside the epidermis of many invertebrates, notably roundworms and arthropods, in which it forms an exoskeleton ... [...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] |
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