One of the ways the lymphatic system aids in maintaining normal blood volume is due to ... the lower pressure of the systemic capillaries pushing interstitial fluid out to enter the lymphatic capillaries. the higher pressure of the systemic capiillaries pushing interstitial fluid out to enter the lymphatic capillaries. the lower pressure of the lymphatic capillaries pushing interstitial fluid out to enter the systemic capillaries. the higher pressure of the lymphatic capillaries pushing interstitial fluid out to enter the systemic capillaries.