Since the circulatory system is a closed loop, cardiac output and venous return are equal.

由于循环系统是闭环，心输出量和静脉回流血量是相等的。

Breathing is one of the mechanisms that facilitate venous return.

呼吸是促进静脉回流的机制之一。

A decrease in right atrial pressure leads to an increase in venous return, and vice versa.

右心房压力降低导致静脉回流增加，反之亦然。

The decrease in venous return of blood to the heart also means that less blood is getting pumped to the lungs, leaving individuals feeling short of breath.

回心血量的减少也意味着更少的血液被泵入双肺，使人感到气短。

Part of this change in pressure is transmitted across the walls of the heart, lowering right atrial pressure and thus facilitating venous return.

这种压力变化部分通过心脏壁传递，降低右心房压力，从而促进静脉回流。

The rate of venous return is determined by two factors: the pressure gradient between venous pressure and right atrial pressure; and venous resistance.

静脉压与右心房压之间的压力梯度；以及静脉阻力。

Thus, the parasympathetic causes slower heart rates and respiratory rates, sleep, increased gastrointestinal track motility, increased peripheral vascular flow, blood flow to all cells, liver and kidneys, and venous return to the heart.

因此，副交感神经引起心率和呼吸频率减慢、睡眠、胃肠运动和周围血流增加、血液流向所有细胞、肝脏和肾脏以及静脉血回流到心脏。