Now, we know that the lymphatic system is under low pressure, and we know this because the lymphatics are not part of the closed circulatory system, so they can't benefit from the pumping of the heart.

现在，我们知道淋巴系统处于低压状态，我们知道这是因为淋巴管不是封闭循环系统的一部分，所以它们不能从心脏的泵血中获益。