Muscle most resistant to the action of non depolarizing muscle relaxants is:

Ref: Ajax Yadav, Short Textbook of Anaesthesia, 1st edition, Page 85Explanation:SEQUENCE OF MUSCLE BLOCKADEFacial muscles are the first muscles to be blocked by both depolarising and nondepolarising muscle relaxants.Diaphragm is the last to be blocked.Sequence of blockade:o Face-Jaw-Pharynx, Larynx- Interco- stalmuscles-Trunk muscles -Limbs muscles-Diaphragm.Sequence of Recovery:o At recovery, muscles recover in reverse order, i.e., first to come is diaphrgam and last to recover are face, pharynx and larynx muscles.Adductor pollicis muscle activity is monitored for neuromuscular blockade. If it shows no activity, it means laryngeal muscles have been blocked already and intubation can be performed.At reversal if there is activity of adductor pollicis. it means power of diaphragm is already back and patient will maintain adequate tidal volume after extubation.Orbicularis oculi is better guide because it corresponds with laryngeal muscles, but technically difficult to measure activity, so not used commonly.