Playing your heart out

The twinning of heart and breath in physiology is a common theme. The regulation of cardiorespiratory coupling across a broad range of physiological demands is a function of the brain. The rhythmicity and pattern of breathing is determined by nerve cell networks in the brain, in automatic fashion. Nerve projections to muscles of the chest bring about the mechanical act of breathing. Similarly, nerve projections from the brain strongly influence the intrinsic pacemaker of the heart. The marriage of heart and breath is revealed in the brain too, with coupling in the activity of nerve cell networks influencing the expression of breath and beat. And all of this, most often, achieved without a moment’s notice.