________________
By balancing ida and pingala nadis, the personality of Ardhanarishwara is created in which the male and female qualities are balanced. In terms of swara yoga, the right side of the brain is activated when the left nostril is flowing, the left side of the brain is activated when the right nostril is flowing, and whenever both nostrils flow equally, every faculty of the human brain is functioning in an optimal and integrated manner as sushumna nadi awakens.
The alternating rhythm of the nasal cycle is necessary for the nervous system as it allows for the sympathetic and parasympathetic systems to operate rhythmically, influencing the behaviour and rhythm of all the other organs in the body and maintaining an inherent balance. The moment the rhythm of the brain is disturbed, the effect spreads through every system of the body. In a mind which is full of anxiety, insecurity or fear, the circuits of the brain are tied in knots. The practice of pranayama restores balance in the ida and pingala nadis and regulates the brain.
Research has also demonstrated the extremely rich and sensitive enervation of the nasal membranes. Studies have shown the presence of twenty times more autonomic nerve fibres within this membrane than in the cerebrospinal (central nervous) system. During inhalation, the flow of air in each nostril stimulates specific unilateral autonomic nerve centres lying within and beneath the mucous membranes, which influence the autonomic processes of respiration, circulation, digestion and so on.
In fact, the whole region of the nasal mucous membrane has been defined as a distinct organ of the autonomic nervous system by some researchers. This means that it responds to various physical and mental situations of arousal, activity, stress and relaxation. In this light, the far-reaching effects of pranayama practices can be understood. Aimed as they are at balancing ida and pingala, the practices thus influence the whole autonomic nervous system, and therefore bring the entire body-mind complex into a state of balance and equilibrium.
103