Neuromuscular Blocking Agents Flashcards
Motor nerves release ____ onto ____ receptors
neuromuscular nicotinic receptors mediate skeletal muscle contraction in response to acetylcholine
Somatic Nerves emanate from the ______ and innervate ______ with ___ synapses outside the CNS
Somatic Nerves emanate from the spinal cord and innervate skeletal muscle with no synapses outside the CNS
Somatic nerve signal terminated by:
Signal is terminated by degradation of Acetylcholine - by Acetylcholinesterases
Anticholinesterases are useful in treating ____________
Anticholinesterases are useful in treating Myasthenia gravis
___________ are useful in treating Myasthenia gravis
Anticholinesterases are useful in treating Myasthenia gravis
Acetylcholine + Acetylcholinesterase –>
Acetate + Choline
Acetylcholine at nicotinic receptor results in …. (pathway)
Na influx
Depolarization
muscle action potential
opening of voltage-sensitive Ca2+ channel
release of Ca2+ from sarcoplasmic reticulum
contraction
Nicotinic receptor historically blocked by
historically blocked by alpha-bungarotoxin from krait or cobra (Naja naja) venom (snake)
Agents prolonging Acetylcholine action (____, _____, _____) _______ muscle depolarization & contraction
Agents prolonging Acetylcholine action (Neostigmine, Pyridostigmine, Edrophonium) augment muscle depolarization & contraction- relevant to Myasthenia gravis
Agents blocking acetycholine release (_______) will prevent both _____ & _______
Agents blocking acetycholine release (Botulinum toxin) will prevent both muscle depolarization & contraction- relevant to cosmetics, muscle spasms
nicotinic receptor blockers (_____, ________) will prevent both ___________ & _________
nicotinic receptor blockers (d-tubocurarine, Mivacurium) will prevent both muscle depolarization & contraction- relevant to surgical paralysis
Something that blocks calcium-induced calcium release (________) will block ________ but not _______
Something that blocks calcium-induced calcium release (Dantrolene) will block contraction but not depolarization- relevant to Malignant Hyperthermia
Autoimmune disease resulting in destruction of nicotinic receptors on skeletal muscle
Myasthenia gravis
Treatment for myasthenia gravis
Treatment includes anticholinesterases (pyridostigmine, neostigmine)
Diagnosis for myasthenia gravis
Diagnosis can include the short acting anticholinesterase edrophonium (Tensilon test)
(Mestinon, Regonol) - used in myasthenia gravis or to reverse competitive neuromuscular antagonism; can be used prophylactically to prevent actions of nerve gases (tabun, soman)
Pyridostigmine
(Prostigmin)- used in myasthenia gravis but poorly absorbed from the gut; used more in hospitalized patients
Neostigmine