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Heart-rate
Heart rate (or pulse rate) is the frequency of the heartbeat measured by the number of contractions (beats) of the heart per minute (bpm). The heart rate can vary according to the body's physical needs, including the need to absorb oxygen and excrete carbon dioxide, but is also modulated by numerous factors, including, but not limited to, genetics, physical fitness, stress or psychological status, diet, drugs, hormonal status, environment, and disease/illness as well as the interaction between and among these factors. It is usually equal or close to the pulse measured at any peripheral point. The American Heart Association states the normal resting adult human heart rate is 60–100 bpm. Tachycardia is a high heart rate, defined as above 100 bpm at rest. Bradycardia is a low heart rate, defined as below 60 bpm at rest. When a human sleeps, a heartbeat with rates around 40–50 bpm is common and is considered normal. When the heart is not beating in a regular pattern, this i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heart
The heart is a muscular organ in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon dioxide to the lungs. In humans, the heart is approximately the size of a closed fist and is located between the lungs, in the middle compartment of the chest. In humans, other mammals, and birds, the heart is divided into four chambers: upper left and right atria and lower left and right ventricles. Commonly the right atrium and ventricle are referred together as the right heart and their left counterparts as the left heart. Fish, in contrast, have two chambers, an atrium and a ventricle, while most reptiles have three chambers. In a healthy heart blood flows one way through the heart due to heart valves, which prevent backflow. The heart is enclosed in a protective sac, the pericardium, which also contains a small amount of fluid. The wall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ketamine
Ketamine is a dissociative anesthetic used medically for induction and maintenance of anesthesia. It is also used as a recreational drug. It is one of the safest anesthetics, as, in contrast with opiates, ether, and propofol, it suppresses neither respiration nor heart rate. Ketamine is also simple to administer and highly tolerable compared to drugs with similar effects which are flammable, irritating, or even explosive. Ketamine is a novel compound, derived from PCP, created in pursuit of a safer anesthetic with similar characteristics. Ketamine is also used for acute pain management. At anesthetic doses, ketamine induces a state of "dissociative anesthesia", a trance-like state providing pain relief, sedation, and amnesia. The distinguishing features of ketamine anesthesia are preserved breathing and airway reflexes, stimulated heart function with increased blood pressure, and moderate bronchodilation. At lower, sub-anesthetic doses, ketamine is a promising agent for pain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bradycardia
Bradycardia (also sinus bradycardia) is a slow resting heart rate, commonly under 60 beats per minute (BPM) as determined by an electrocardiogram. It is considered to be a normal heart rate during sleep, in young and healthy or elderly adults, and in athletes. In some people, bradycardia below 60 BPM may be associated with fatigue, weakness, dizziness, sweating, and fainting. The term "relative bradycardia" is used to refer to a heart rate slower than an individual's typical resting heart rate. Athletes may have athletic heart syndrome, which includes bradycardia as part of the cardiovascular adaptations to training and participation. The word "bradycardia" is from the Greek βραδύς ''bradys'' "slow", and καρδία ''kardia'' "heart". Classification Sinus Atrial bradycardias are divided into three types. The first, respiratory sinus arrhythmia, is usually found in young and healthy adults. Heart rate increases during inhalation and decreases during exhalation. Thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency
Frequency is the number of occurrences of a repeating event per unit of time. It is also occasionally referred to as ''temporal frequency'' for clarity, and is distinct from ''angular frequency''. Frequency is measured in hertz (Hz) which is equal to one event per second. The period is the interval of time between events, so the period is the reciprocal of the frequency. For example, if a heart beats at a frequency of 120 times a minute (2 hertz), the period, —the interval at which the beats repeat—is half a second (60 seconds divided by 120 beats). Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio signals (sound), radio waves, and light. Definitions and units For cyclical phenomena such as oscillations, waves, or for examples of simple harmonic motion, the term ''frequency'' is defined as the number of cycles or vibrations per unit of time. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parasympathetic Nervous System
The parasympathetic nervous system (PSNS) is one of the three divisions of the autonomic nervous system, the others being the sympathetic nervous system and the enteric nervous system. The enteric nervous system is sometimes considered part of the autonomic nervous system, and sometimes considered an independent system. The autonomic nervous system is responsible for regulating the body's unconscious actions. The parasympathetic system is responsible for stimulation of "rest-and-digest" or "feed and breed" activities that occur when the body is at rest, especially after eating, including sexual arousal, salivation, lacrimation (tears), urination, digestion, and defecation. Its action is described as being complementary to that of the sympathetic nervous system, which is responsible for stimulating activities associated with the fight-or-flight response. Nerve fibres of the parasympathetic nervous system arise from the central nervous system. Specific nerves include several ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tachycardia
Tachycardia, also called tachyarrhythmia, is a heart rate that exceeds the normal resting rate. In general, a resting heart rate over 100 beats per minute is accepted as tachycardia in adults. Heart rates above the resting rate may be normal (such as with exercise) or abnormal (such as with electrical problems within the heart). Complications Tachycardia can lead to fainting. When the rate of blood flow becomes too rapid, or fast blood flow passes on damaged endothelium, it increases the friction within vessels resulting in turbulence and other disturbances. According to the Virchow's triad, this is one of the three conditions that can lead to thrombosis (i.e., blood clots within vessels). Causes Some causes of tachycardia include: * Adrenergic storm * Anaemia * Anxiety * Atrial fibrillation * Atrial flutter * Atrial tachycardia * Atrioventricular reentrant tachycardia * AV nodal reentrant tachycardia * Brugada syndrome * Circulatory shock and its various causes ( obstr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sedative
A sedative or tranquilliser is a substance that induces sedation by reducing irritability or excitement. They are CNS depressants and interact with brain activity causing its deceleration. Various kinds of sedatives can be distinguished, but the majority of them affect the neurotransmitter gamma-aminobutyric acid (GABA). In spite of the fact that each sedative acts in its own way, most produce relaxing effects by increasing GABA activity. This group is related to hypnotics. The term ''sedative'' describes drugs that serve to calm or relieve anxiety, whereas the term ''hypnotic'' describes drugs whose main purpose is to initiate, sustain, or lengthen sleep. Because these two functions frequently overlap, and because drugs in this class generally produce dose-dependent effects (ranging from anxiolysis to loss of consciousness) they are often referred to collectively as ''sedative-hypnotic'' drugs. Sedatives can be used to produce an overly-calming effect ( alcohol being the m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Depressant
A depressant, or central depressant, is a drug that lowers neurotransmission levels, which is to depress or reduce arousal or stimulation, in various areas of the brain. Depressants are also colloquially referred to as downers as they lower the level of arousal when taken. Stimulants or "uppers" increase mental or physical function, hence the opposite drug class of depressants is stimulants, not antidepressants. Depressants are widely used throughout the world as prescription medicines and as illicit substances. Alcohol is a very prominent depressant. Alcohol can be and is more likely to be a large problem among teenagers and young adults. When depressants are used, effects often include ataxia, anxiolysis, pain relief, sedation or somnolence, and cognitive or memory impairment, as well as in some instances, euphoria, dissociation, muscle relaxation, lowered blood pressure or heart rate, respiratory depression, and anticonvulsant effects. Depressants also act to produce anes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Substituted Amphetamine
Substituted amphetamines are a class of compounds based upon the amphetamine structure; it includes all derivative compounds which are formed by replacing, or substituting, one or more hydrogen atoms in the amphetamine core structure with substituents. The compounds in this class span a variety of pharmacological subclasses, including stimulants, empathogens, and hallucinogens, among others. Examples of substituted amphetamines are amphetamine (itself), methamphetamine, ephedrine, cathinone, phentermine, mephentermine, bupropion, methoxyphenamine, selegiline, amfepramone (diethylpropion), pyrovalerone, MDMA (ecstasy), and DOM (STP). Some of amphetamine's substituted derivatives occur in nature, for example in the leaves of ''Ephedra'' and khat plants. Amphetamine was first produced at the end of the 19th century. By the 1930s, amphetamine and some of its derivative compounds found use as decongestants in the symptomatic treatment of colds and also occasionally as psychoac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stimulant
Stimulants (also often referred to as psychostimulants or colloquially as uppers) is an overarching term that covers many drugs including those that increase activity of the central nervous system and the body, drugs that are pleasurable and invigorating, or drugs that have Sympathomimetic drug, sympathomimetic effects. Stimulants are widely used throughout the world as prescription medicines as well as without a prescription (either legally or Prohibition (drugs), illicitly) as performance-enhancing substance, performance-enhancing or recreational drug use, recreational drugs. Among narcotics, stimulants produce a noticeable crash or ''Comedown (drugs), comedown'' at the end of their effects. The most frequently prescribed stimulants as of 2013 were lisdexamfetamine (Vyvanse), methylphenidate (Ritalin), and amphetamine (Adderall). It was estimated in 2015 that the percentage of the world population that had used cocaine during a year was 0.4%. For the category "amphetamines and p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Nervous System
The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain and spinal cord. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all parts of the bodies of bilaterally symmetric and triploblastic animals—that is, all multicellular animals except sponges and diploblasts. It is a structure composed of nervous tissue positioned along the rostral (nose end) to caudal (tail end) axis of the body and may have an enlarged section at the rostral end which is a brain. Only arthropods, cephalopods and vertebrates have a true brain (precursor structures exist in onychophorans, gastropods and lancelets). The rest of this article exclusively discusses the vertebrate central nervous system, which is radically distinct from all other animals. Overview In vertebrates, the brain and spinal cord are both enclosed in the meninges. The meninges provide a barrier to chemicals dissolv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Electrocardiology
The ''Journal of Electrocardiology'' is a peer-reviewed medical journal covering electrocardiography, vectorcardiography, Cardiac arrhythmias, membrane action potential, cardiac pacing An artificial cardiac pacemaker (or artificial pacemaker, so as not to be confused with the natural cardiac pacemaker) or pacemaker is a medical device that generates electrical impulses delivered by electrodes to the chambers of the heart eith ..., Defibrillation, monitoring defibrillation, instrumentation, drug effects, and computer applications. It is the official journal of the International Society for Computerized Electrocardiology and the International Society of Electrocardiology. Abstracting and indexing The journal is abstracted and indexed in: * Current Contents/Clinical Medicine * EMBASE * Index Medicus/MEDLINE/PubMed * Science Citation Index * Scopus According to the ''Journal Citation Reports'', the journal has a 2013 impact factor of 1.363. References External links ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
