Definition: "Part of the circulatory system that consists of a series of vessels that collect blood (exclusive of erythrocytes) which seeps through capillary walls and return it to the veins. The lymphatic system of vasculature drains lymph fluid from the tissue spaces of most organs and returns it to the blood vasculature for recirculation. The lymphatic sytem functions in immune responses. Anurans generate a lot of lymphatic fluid, largely as a consequence of their very leaky vasculature and high interstitial compliance. Lymph is ultimately pumped into the venous system by paired, dorsally located lymph hearts. Hedrick et al (2007) showed that lung inflation and deflation assists lymph movement. Lymph is moved during lung deflation to the subvertebral sac from anterior and posterior lymph sacs. During lung inflation, increased lymph sac pressure moves lymph to axillary regions, where lymph hearts can return lymph to the vascular space."