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Dysbarism
Dysbarism or dysbaric disorders are medical conditions resulting from changes in ambient pressure. Various activities are associated with pressure changes. Underwater diving is a frequently cited example, but pressure changes also affect people who work in other pressurized environments (for example, caisson workers), and people who move between different altitudes. A dysbaric disorder may be acute or chronic. Ambient pressure Ambient pressure on a diver is the pressure in the water around the diver (or the air, with caisson workers etc.). It is the sum of the atmospheric pressure at the surface and hydrostatic pressure due to the depth. As a diver descends, the ambient pressure increases. At in seawater, it is twice the normal atmospheric pressure at the surface. At 40 meters (a common recommended limit for recreational diving) it is 5 times the pressure at sea level. Pressure decreases with altitude above sea level, but less dramatically. At 3000 feet altitude (almost 10 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diving Disorders
Diving disorders, or diving related medical conditions, are conditions associated with underwater diving, and include both conditions unique to underwater diving, and those that also occur during other activities. This second group further divides conditions caused by exposure to ambient pressures significantly different from surface atmospheric pressure, and a range of conditions caused by general environment and equipment associated with diving activities. Disorders particularly associated with diving include those caused by variations in ambient pressure, such as barotraumas of descent and ascent, decompression sickness and those caused by exposure to elevated ambient pressure, such as some types of gas toxicity. There are also non-dysbaric disorders associated with diving, which include the effects of the aquatic environment, such as drowning, which also are common to other water users, and disorders caused by the equipment or associated factors, such as carbon dioxide and ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ambient Pressure
The ambient pressure on an object is the pressure of the surrounding medium, such as a gas or liquid, in contact with the object. Atmosphere Within the atmosphere, the ambient pressure decreases as elevation increases. By measuring ambient atmospheric pressure, a pilot may determine altitude (see pitot-static system). Near sea level, a change in ambient pressure of 1 millibar is taken to represent a change in height of . Underwater The ambient pressure in water with a free surface is a combination of the hydrostatic pressure due to the weight of the water column and the atmospheric pressure on the free surface. This increases approximately linearly with depth. Since water is much denser than air, much greater changes in ambient pressure can be experienced under water. Each of depth adds another bar (unit) , bar to the ambient pressure. Ambient-pressure diving is underwater diving exposed to the water pressure at depth, rather than in a pressure-excluding atmospheric diving suit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henry's Law
In physical chemistry, Henry's law is a gas law that states that the amount of dissolved gas in a liquid is directly proportional at equilibrium to its partial pressure above the liquid. The proportionality factor is called Henry's law constant. It was formulated by the English chemist William Henry, who studied the topic in the early 19th century. In simple words, it states that the partial pressure of a gas in the vapour phase is directly proportional to the mole fraction of a gas in solution. An example where Henry's law is at play is the depth-dependent dissolution of oxygen and nitrogen in the blood of underwater divers that changes during decompression, going to decompression sickness. An everyday example is carbonated soft drinks, which contain dissolved carbon dioxide. Before opening, the gas above the drink in its container is almost pure carbon dioxide, at a pressure higher than atmospheric pressure. After the bottle is opened, this gas escapes, moving the partial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physiological
Physiology (; ) is the science, scientific study of function (biology), functions and mechanism (biology), mechanisms in a life, living system. As a branches of science, subdiscipline of biology, physiology focuses on how organisms, organ systems, individual organ (biology), organs, cell (biology), cells, and biomolecules carry out chemistry, chemical and physics, physical functions in a living system. According to the classes of organisms, the field can be divided into clinical physiology, medical physiology, Zoology#Physiology, animal physiology, plant physiology, cell physiology, and comparative physiology. Central to physiological functioning are biophysics, biophysical and biochemical processes, homeostasis, homeostatic control mechanisms, and cell signaling, communication between cells. ''Physiological state'' is the condition of normal function. In contrast, ''pathology, pathological state'' refers to abnormality (behavior), abnormal conditions, including human diseases. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurological
Neurology (from , "string, nerve" and the suffix -logia, "study of") is the branch of medicine dealing with the diagnosis and treatment of all categories of conditions and disease involving the nervous system, which comprises the brain, the spinal cord and the peripheral nerves. Neurological practice relies heavily on the field of neuroscience, the scientific study of the nervous system, using various techniques of neurotherapy. IEEE Brain (2019). "Neurotherapy: Treating Disorders by Retraining the Brain". ''The Future Neural Therapeutics White Paper''. Retrieved 23.01.2025 from: https://brain.ieee.org/topics/neurotherapy-treating-disorders-by-retraining-the-brain/#:~:text=Neurotherapy%20trains%20a%20patient's%20brain,wave%20activity%20through%20positive%20reinforcement International Neuromodulation Society, Retrieved 23 January 2025 from: https://www.neuromodulation.com/ Val Danilov I (2023). "The Origin of Natural Neurostimulation: A Narrative Review of Noninvasive Brain S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethanol
Ethanol (also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound with the chemical formula . It is an Alcohol (chemistry), alcohol, with its formula also written as , or EtOH, where Et is the pseudoelement symbol for ethyl group, ethyl. Ethanol is a Volatility (chemistry), volatile, flammable, colorless liquid with a characteristic wine-like odor and pungent taste. As a psychoactive depressant, it is the active ingredient in alcoholic beverages, and the second most consumed drug globally behind caffeine. Ethanol is naturally produced by the fermentation process of sugars by yeasts or via petrochemical processes such as ethylene hydration. Historically it was used as a general anesthetic, and has modern medical applications as an antiseptic, disinfectant, solvent for some medications, and antidote for methanol poisoning and ethylene glycol poisoning. It is used as a chemical solvent and in the Chemical synthesis, synthesis of orga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cross-tolerance
Cross-tolerance is a phenomenon that occurs when tolerance to the effects of a certain drug produces tolerance to another drug. It often happens between two drugs with similar functions or effects—for example, acting on the same cell receptor or affecting the transmission of certain neurotransmitters. Cross-tolerance has been observed with pharmaceutical drugs such as anti-anxiety agents and illicit substances, and sometimes the two of them together. Often, a person who uses one drug can be tolerant to a drug that has a completely different function.Kolb, Bryan, and Ian Whishaw. An Introduction to Brain and Behavior. New York: Worth Publishers, 2014. Print. This phenomenon allows one to become tolerant to a drug that they have never used before. Drug classifications and cross-tolerance Anxiolytics and sedatives Excitation of the GABA receptor produces an influx of negatively charged chloride ions, which hyperpolarizes the neuron and makes it less likely to give rise to an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laughing Gas
Nitrous oxide (dinitrogen oxide or dinitrogen monoxide), commonly known as laughing gas, nitrous, or factitious air, among others, is a chemical compound, an oxide of nitrogen with the formula . At room temperature, it is a colourless non-flammable gas, and has a slightly sweet scent and taste. At elevated temperatures, nitrous oxide is a powerful oxidiser similar to molecular oxygen. Nitrous oxide has significant medical uses, especially in surgery and dentistry, for its anaesthetic and pain-reducing effects, and it is on the World Health Organization's List of Essential Medicines. Its colloquial name, "laughing gas", coined by Humphry Davy, describes the euphoric effects upon inhaling it, which cause it to be used as a recreational drug inducing a brief "high". When abused chronically, it may cause neurological damage through inactivation of vitamin B12. It is also used as an oxidiser in rocket propellants and motor racing fuels, and as a frothing gas for whipped cre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrous Oxide
Nitrous oxide (dinitrogen oxide or dinitrogen monoxide), commonly known as laughing gas, nitrous, or factitious air, among others, is a chemical compound, an Nitrogen oxide, oxide of nitrogen with the Chemical formula, formula . At room temperature, it is a colourless Flammability#Definitions, non-flammable gas, and has a slightly sweet scent and taste. At elevated temperatures, nitrous oxide is a powerful Oxidising agent, oxidiser similar to molecular oxygen. Nitrous oxide has significant Nitrous oxide (medication), medical uses, especially in surgery and dentistry, for its Anesthesia, anaesthetic and Analgesic, pain-reducing effects, and it is on the WHO Model List of Essential Medicines, World Health Organization's List of Essential Medicines. Its colloquial name, "laughing gas", coined by Humphry Davy, describes the Euphoria, euphoric effects upon inhaling it, which cause it to be used as a recreational drug inducing a brief "Dissociative, high". When abused chronically ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraplegia
Paraplegia, or paraparesis, is an impairment in motor or sensory function of the lower extremities. The word comes from Ionic Greek () "half-stricken". It is usually caused by spinal cord injury or a congenital condition that affects the neural (brain) elements of the spinal canal. The area of the spinal canal that is affected in paraplegia is either the thoracic, lumbar, or sacral regions. If four limbs are affected by paralysis, tetraplegia or quadriplegia is the correct term. If only one limb is affected, the correct term is monoplegia. Spastic paraplegia is a form of paraplegia defined by spasticity of the affected muscles, rather than flaccid paralysis. The American Spinal Injury Association classifies spinal cord injury severity in the following manner. ASIA A is the complete loss of sensory function and motor skills below the injury. ASIA B is having some sensory function below the injury, but no motor function. In ASIA C, there is some motor function below the le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paralysis
Paralysis (: paralyses; also known as plegia) is a loss of Motor skill, motor function in one or more Skeletal muscle, muscles. Paralysis can also be accompanied by a loss of feeling (sensory loss) in the affected area if there is sensory damage. In the United States, roughly 1 in 50 people have been diagnosed with some form of permanent or transient paralysis. The word "paralysis" derives from the Greek language, Greek παράλυσις, meaning "disabling of the nerves" from παρά (''para'') meaning "beside, by" and λύσις (''lysis'') meaning "making loose". A paralysis accompanied by involuntary tremors is usually called "palsy". Causes Paralysis is most often caused by damage in the nervous system, especially the spinal cord. Other major causes are stroke, Physical trauma, trauma with nerve injury, poliomyelitis, cerebral palsy, peripheral neuropathy, Parkinson's disease, ALS, botulism, spina bifida, multiple sclerosis and Guillain–Barré syndrome. Incidents th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seizure
A seizure is a sudden, brief disruption of brain activity caused by abnormal, excessive, or synchronous neuronal firing. Depending on the regions of the brain involved, seizures can lead to changes in movement, sensation, behavior, awareness, or consciousness. Symptoms vary widely. Some seizures involve subtle changes, such as brief lapses in attention or awareness (as seen in absence seizures), while others cause generalized convulsions with loss of consciousness ( tonic–clonic seizures). Most seizures last less than two minutes and are followed by a postictal period of confusion, fatigue, or other symptoms. A seizure lasting longer than five minutes is a medical emergency known as status epilepticus. Seizures are classified as provoked, when triggered by a known cause such as fever, head trauma, or metabolic imbalance, or unprovoked, when no immediate trigger is identified. Recurrent unprovoked seizures define the neurological condition epilepsy. Clinical features Seizur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
