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Shock
Shock may refer to: Common uses Healthcare * Acute stress reaction, also known as psychological or mental shock ** Shell shock, soldiers' reaction to battle trauma * Circulatory shock, a medical emergency ** Cardiogenic shock, resulting from dysfunction of the heart ** Distributive shock, resulting from an abnormal distribution of blood flow *** Septic shock, a result of severe infection **** Toxic shock syndrome, a specific type of severe infection *** Anaphylactic shock, a result of severe allergic reaction *** Neurogenic shock, due to a high spinal cord injury disrupting the sympathetic nervous system ** Hypovolemic shock, resulting from an insufficient blood volume *** Hemorrhagic shock, from a large volume lost to bleeding **Obstructive shock, resulting from mechanical obstruction of blood flow * Cold shock response of organisms to sudden cold, especially cold water * Electric shock ** Defibrillation, electric shock to restore heart rhythm ** Electroconvulsive therapy or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Obstructive Shock
Obstructive shock is one of the four types of shock, caused by a physical obstruction in the flow of blood. Obstruction can occur at the level of the great vessels or the heart itself. Causes include pulmonary embolism, cardiac tamponade, and tension pneumothorax. These are all life-threatening. Symptoms may include shortness of breath, weakness, or altered mental status. Low blood pressure and tachycardia are often seen in shock. Other symptoms depend on the underlying cause. The physiology of obstructive shock is similar to cardiogenic shock. In both types, the heart's output of blood (cardiac output) is decreased. This causes a back-up of blood into the veins entering the right atrium. Jugular venous distension can be observed in the neck. This finding can be seen in obstructive and cardiogenic shock. With the decrease cardiac output, blood flow to vital tissues is decreased. Poor perfusion to organs leads to shock. Due to these similarities, some sources place obstructive sho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypovolemic Shock
Hypovolemic shock is a form of Shock (circulatory), shock caused by severe hypovolemia (insufficient blood volume or extracellular fluid in the body). It can be caused by severe dehydration or blood loss. Hypovolemic shock is a medical emergency; if left untreated, the Ischemia, insufficient blood flow can cause damage to organs, leading to multiple organ failure. In treating hypovolemic shock, it is important to determine the cause of the underlying hypovolemia, which may be the result of hemorrhage, bleeding or other fluid losses. To minimize ischemic damage to tissues, treatment involves quickly replacing lost blood or fluids, with consideration of both rate and the type of fluids used. Tachycardia, a fast heart rate, is typically the first abnormal vital sign. When resulting from blood loss, trauma is the most common root cause, but severe blood loss can also happen in various body systems without clear traumatic injury. The body in hypovolemic shock prioritizes getting oxyg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemorrhagic Shock
Hypovolemic shock is a form of shock caused by severe hypovolemia (insufficient blood volume or extracellular fluid in the body). It can be caused by severe dehydration or blood loss. Hypovolemic shock is a medical emergency; if left untreated, the insufficient blood flow can cause damage to organs, leading to multiple organ failure. In treating hypovolemic shock, it is important to determine the cause of the underlying hypovolemia, which may be the result of bleeding or other fluid losses. To minimize ischemic damage to tissues, treatment involves quickly replacing lost blood or fluids, with consideration of both rate and the type of fluids used. Tachycardia, a fast heart rate, is typically the first abnormal vital sign. When resulting from blood loss, trauma is the most common root cause, but severe blood loss can also happen in various body systems without clear traumatic injury. The body in hypovolemic shock prioritizes getting oxygen to the brain and heart, which reduces ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acute Stress Reaction
Acute stress reaction (ASR), also known as psychological shock, mental shock, or simply shock, as well as acute stress disorder (ASD), is a psychological response to a terrifying, Psychological trauma, traumatic, or surprising experience. The reactions may include but are not limited to intrusive thoughts, or Dissociation (psychology), dissociation, and reactivity symptoms such as Avoidance coping, avoidance or hyperarousal. It may be exhibited for days or weeks after the traumatic event. If the condition is not correctly addressed, it may develop into post-traumatic stress disorder (PTSD). Diagnosis The International Classification of Diseases (ICD) treats this condition differently from the Diagnostic and Statistical Manual of Mental Disorders (DSM). According to the ICD-11, acute stress reaction refers to the symptoms experienced a few hours to a few days after exposure to a traumatic event. In contrast, DSM-5 defines acute stress disorder by symptoms experienced 48 hours t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shock (mechanics)
In mechanics and physics, shock is a sudden acceleration caused, for example, by impact (mechanics), impact, drop, kick, earthquake, or explosion. Shock is a transient physical excitation. Shock describes matter subject to extreme rates of force with respect to time. Shock is a vector that has units of an acceleration (rate of change of velocity). The unit ''g'' (or ''g'') represents multiples of the standard acceleration of gravity and is conventionally used. A shock pulse can be characterised by its peak acceleration, the duration, and the shape of the shock pulse (half sine, triangular, trapezoidal, etc.). The shock response spectrum is a method for further evaluating a mechanical shock. Shock measurement Shock measurement is of interest in several fields such as *Propagation of heel shock through a runner's body *Measure the magnitude of a shock need to cause damage to an item: fragility. *Measure shock attenuation through athletic flooring *Measuring the effectiveness ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shock Absorber
A shock absorber or damper is a mechanical or hydraulics, hydraulic device designed to absorb and Damping ratio, damp shock (mechanics), shock impulses. It does this by converting the kinetic energy of the shock into another form of energy (typically thermal energy, heat) which is then dissipated. Most shock absorbers are a form of dashpot (a damper which resists motion via viscous friction). Description Pneumatic and hydraulic shock absorbers are used in conjunction with cushions and springs. An automobile shock absorber contains spring-loaded check valves and orifices to control the flow of oil through an internal piston (see below). One design consideration, when designing or choosing a shock absorber, is where that energy will go. In most shock absorbers, energy is converted to heat inside the viscous fluid. In hydraulic cylinders, the hydraulic fluid heats up, while in Pneumatic cylinder, air cylinders, the hot air is usually exhausted to the atmosphere. In other types of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shock Mount
A shock mount or isolation mount is a mechanical fastener that connects two parts elastically to provide shock (mechanics), shock and vibration isolation. Isolation mounts allow equipment to be securely mounted to a foundation and/or frame and, at the same time, allow it to float independently from it. Uses Shock mounts are found in a wide variety of applications. They can be used to isolate the foundation or substrate from the dynamics of the mounted equipment. This is vital on submarines where silence is critical to mission success. Yachts also use shock mounts to dampen mechanical noise (mainly transmitted throughout the structure) and increase comfort. This is usually done through elastic supports and transmission couplings. Other common examples are the motor and transmission mounts used in virtually every automobile manufactured today. Without isolation mounts, interior noise and comfort levels would be significantly different. Such shock and vibration-isolation mounts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shock Wave
In physics, a shock wave (also spelled shockwave), or shock, is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a medium, but is characterized by an abrupt, nearly discontinuous, change in pressure, temperature, and density of the medium. For the purpose of comparison, in supersonic speed, supersonic flows, additional increased expansion may be achieved through an expansion fan, also known as a Prandtl–Meyer expansion fan. The accompanying expansion wave may approach and eventually collide and recombine with the shock wave, creating a process of destructive interference. The sonic boom associated with the passage of a supersonic aircraft is a type of sound wave produced by Wave interference, constructive interference. Unlike solitons (another kind of nonlinear wave), the energy and speed of a shock wave alone dissipates relatively quickly with distan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oblique Shock
An oblique shock wave is a shock wave that, unlike a normal shock, is inclined with respect to the direction of incoming air. It occurs when a supersonic flow encounters a corner that effectively turns the flow into itself and compresses. The upstream streamlines are uniformly deflected after the shock wave. The most common way to produce an oblique shock wave is to place a wedge into supersonic, compressible flow. Similar to a normal shock wave, the oblique shock wave consists of a very thin region across which nearly discontinuous changes in the thermodynamic properties of a gas occur. While the upstream and downstream flow directions are unchanged across a normal shock, they are different for flow across an oblique shock wave. It is always possible to convert an oblique shock into a normal shock by a Galilean transformation. Wave theory For a given Mach number, M1, and corner angle, θ, the oblique shock angle, β, and the downstream Mach number, M2, can be calcu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insulin Shock Therapy
Insulin shock therapy or insulin coma therapy was a form of psychiatric treatment in which patients were repeatedly injected with large doses of insulin in order to produce daily comas over several weeks.Neustatter WL (1948) ''Modern psychiatry in practice.'' London: 224. It was introduced in 1927 by Austrian-American psychiatrist Manfred Sakel and used extensively in the 1940s and 1950s, mainly for schizophrenia, before falling out of favour and being replaced by neuroleptic drugs in the 1960s. It was one of a number of physical treatments introduced into psychiatry in the first four decades of the 20th century. These included the convulsive therapies ( cardiazol/metrazol therapy and electroconvulsive therapy), deep sleep therapy, and psychosurgery. Insulin coma therapy and the convulsive therapies are collectively known as the shock therapies. Origins In 1927, Sakel, who had recently qualified as a medical doctor in Vienna and was working in a psychiatric clinic in Berli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shock (fluid Dynamics)
Shock is an abrupt discontinuity in the flow field and it occurs in flows when the local flow speed exceeds the local sound speed.Courant, Richard, and K.O. Friedrichs. Supersonic Flow and Shock Waves'. Springer Science & Business Media, 1999. 2-3. More specifically, it is a flow whose Mach number exceeds 1. Explanation of phenomena Shock is formed due to coalescence of various small pressure pulses. Sound waves are pressure waves and it is at the speed of the sound wave the disturbances are ''communicated'' in the medium. When an object is moving in a flow field the object sends out disturbances which propagate at the speed of sound and ''adjusts'' the remaining flow field accordingly. However, if the object itself happens to travel at speed greater than sound, then the disturbances created by the object would not have traveled and ''communicated'' to the rest of the flow field and this results in an abrupt change of property, which is termed as ''shock'' in gas dynamics term ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bow Shock
In astrophysics, bow shocks are shock waves in regions where the conditions of density and pressure change dramatically due to blowing stellar wind. Bow shock occurs when the magnetosphere of an astrophysical object interacts with the nearby flowing ambient plasma such as the solar wind. For Earth and other magnetized planets, it is the boundary at which the speed of the stellar wind abruptly drops as a result of its approach to the magnetopause. For stars, this boundary is typically the edge of the astrosphere, where the stellar wind meets the interstellar medium. Description The defining criterion of a shock wave is that the bulk velocity of the plasma drops from " supersonic" to "subsonic", where the speed of sound cs is defined by c_s^2 = \gamma p/ \rho where \gamma is the ratio of specific heats, p is the pressure, and \rho is the density of the plasma. A common complication in astrophysics is the presence of a magnetic field. For instance, the charged particl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
