 Hello everyone, in this video we shall discuss the short note answer for muscle relaxance in general anesthesia skeletal muscle relaxance and drugs that act very clearly at the neuromuscular junction or muscle fiber itself or centrally in the cerebrospinal axis to reduce muscle tone and or cause paralysis so basically there are two types the ones which act very clearly which are also known as neuromuscular blockers the other group the centrally acting one acts the cerebrospinal axis the neuromuscular blocking agents or the peripherally acting muscle relaxance are used in conjunction with general anesthetics to provide muscle relaxation for surgery while the centrally acting muscle relaxance are used primarily for painful muscle spasms and spastic neurologic diseases the muscle relaxance are classified according to mode of action as repolarizing or non-competitive muscle relaxance and as non-repolarizing or competitive muscle relaxance as you all know acetylcholine is a neurotransmitter which is found at the neuromuscular junction repolarizing muscle relaxance act as acetylcholine receptor agonist by binding to the ACS receptors of the motor and plate thus generating an action prevention so that is why it is known as repolarizing or non-competitive muscle relaxance for example succinylcholine the next type non-repolarizing or competitive muscle relaxance is the one which act as competitive antagonist they bind to the ACS receptors but they are unable to induce ion channel openings the examples include D-therocurainin pancheronium which are long acting muscle relaxance intermediate acting muscle relaxance is x-y-curium and neuraturium is a short acting non-repolarizing muscle relaxance according to the site of action muscle relaxance are again classified into direct acting and simply acting direct acting spiltal muscle relaxance inhibit muscle contraction by decreasing the calcium release from the sarcoplasmic reticulum in muscles for example Danfolium so Danfolium is a direct acting muscle relaxant simply acting muscle relaxance are words which reduce the skeletal muscle cone by a selective action in the cellicose spinal axis without altering consciousness so all simply acting muscle relaxance do have some amount of serrated property and they overlap with the anti-anxiety parts both the direct acting and simply acting muscle relaxance have no effect on neural muscular transition, transmission and on muscle flexors let's see the action of muscle relaxance on various systems skeletal muscles intravenous injection of non-repolarizing blockers rapidly produces muscle weakness followed by plastic paralysis the small fast response muscles are affected first it spreads to the hands, feet, arms, legs, neck, face and tongue finally the intercostal muscles the diaphragm all these are affected and then the respiration stops recovery occurs in the reverse sequence diaphragmatic contractions reduce first depolarizing blockers typically produce passipulations lasting for seconds few seconds before inducing plastic paralysis plastic paralysis of limbs means where the limbs appear hanging and very loose that is known as plastic paralysis that is the action of muscle relaxant on the autonomic gland here there is inhibition of autonomic activity by interfering with the neurovoin solution within autonomic gland here this reduces sympathetic outflow to the heart thereby decreasing cardiac outtook by decreasing heart rate and heart contractility regarding histamine release that is D-tubocuririn reduces histamine from muscles thus resulting in hypopension, crushing, bronchospasm and increased respiratory sickles on CVS D-tubocuririn reduces significant fall in the blood pressure this is due to ganglionic blockage, histamine release and reduced weakness return this is a result of paralysis of limb and respiratory muscles on gastrointestinal tract the ganglionic blocking activity of competitive blockers may enhance the post-operative paralytic elias after abdominal operations so this action of muscle relaxant is very useful because it enhances the post-operative paralysis of elias so the elias don't move or the motion will be reduced which is very useful after abdominal operations on the CNS all the neuromuscular blockers are coronary compounds which means they don't cross the blood-brain barrier and hence no side effects let's see what are the different uses of a muscle relaxant the most important use of neuromuscular blockers is as adjuvants to general anesthesia adequate muscle relaxation can be achieved at lighter planes they are specially valuable in abdominal and thoracic surgery in dentistry they may be required for creating mandibular fractures or maxillofacial fractures succinylcholine is employed for brief procedures for example endocrychial intubation or laryngeoscopy or reduction of fractures and to create laryngeal spasm succinylcholine is a brief acting muscle relaxant convulsions and trauma from electroconvulsive therapy can be avoided by the use of relaxants severe cases of thickness and status epilepticus all these conditions may be paralysed by a neuromuscular blocker so these are the different uses of a muscle relaxant complications of muscle relaxants due to toxicity or overloads include respiratory paralysis and prolonged apnea which is the most important complication flushing can occasionally occur with agents like acrochurium and mucocurium fall in blood pressure and cardiovascular collapse can occur specially in hypervolumic patients cardiac arrhythmia and even cardiac arrest can occur especially with succinylcholine recitation of asthma with histamine-releasing neuromuscular blockers is also common post-operative muscle soreness can occur after administration of succinylcholine so that's all about muscle relaxant symptoms in renal anesthesia thanks for watching