PATHOLOGY

Detailed explanation-1: -Your parasympathetic nervous system is a network of nerves that relaxes your body after periods of stress or danger. It also helps run life-sustaining processes, like digestion, during times when you feel safe and relaxed.

Detailed explanation-2: -Like humming, singing naturally activates it. Yawning is a built-in repair circuit which activates the parasympathetic nervous system and signals rest/digest processes for body. If it doesn’t come naturally, intentionally yawning can still exercise and strengthen this connection.