Complex sentence: Carbon dioxide (CO 2) generated in tissues passively diffuses into the interstitial fluid, subsequently entering capillaries, and finally entering the RBCs, balancing the intracellular and extracellular CO 2 concentrations.
Split into simpler sentences: Carbon dioxide (CO 2) generated in tissues passively diffuses into capillaries via the interstitial fluid. Once in circulation, CO 2 enters red blood cells (RBCs) to balance the intracellular and extracellular CO 2 concentrations.