Figure 4
Suction persisted along the length of the lymphatic vessel (N = 1). (A) Pressure was measured at two locations: p 1, downstream of V1 (black), p 2, upstream of V5 (green), D was measured at the indicated site. (B) Left: traces of p 1 (black), p 2 (green), and D (for p in = p out = 3, p e = 0.5 cmH2O). Right: traces of p 1 (magenta), p 2 (green), and D, with R capillary upstream. (C) Suction amp increased while p max dropped at p 2 with or without R capillary upstream. Error bars indicate standard deviation. *Significant difference from measurement at site 1 (t-test, p < 0.01). (D) Predictions from mathematical modelling for p in = p out = 3, p e = 0.5 cmH2O. Left (without R capillary): traces of p 1 (black), p 2 (green), and Q 1 (flow through first valve, black), Q 3 (flow through middle (third) valve, black dashed line), Q 5 (flow through last (fifth) valve, green). Right: traces of p 1 (magenta), p 2 (green), and Q 1 (magenta), Q 3 (magenta dashed line), Q 5 (green), with R capillary upstream. Background shadings refer to the valve states presented in Fig. 2C. Flow profiles indicated that inlet valve (bottom panel - left: without R capillary, Q 1, black, right: with R capillary, Q 1, magenta) exclusively opens during suction, whereas the outlet valve (bottom panel - left: without R capillary, Q 5, green, right: with R capillary, Q 5, green) is shut during that period and only opens when upstream lymphangions are contracting.
