Muscular timidity caused by opioids is due to the agonist effect on which receptor
Refer Miller 7/ep781 Truncal rigidity caused by highly lipid soluble opioids like Fentanyl is supraspinal in origin. It is mainly caused by stimulation of mu receptors whereas kappa and delta receptors tend to reduce the rigidity
Mu
Kappa
Delta
Sigma
Anesthesia