Fluid movement in the lymphatic circulation

Water moves from the blood, through the capillary wall and into the interstitial space. Some of this water is reabsorbed into distal regions of the capillary, or other vessels, but a substantial quantity of water is lost from the vascular into the interstitial volume. In humans, this loss amounts to 4 L/day. 

The lymphatic vessels carry this interstitial fluid back to the circulatory system. Lymphatic vessels are structurally similar to capillaries they have a wall formed by a single layer of endothelial cells. The lymph vessel wall, how- 

Lymph vessels in tissues appear to be 40 /um in diameter and flattened. In the skin of the mouse tail, the lymph vessels form a uniform hexagonal network [15]. Local residence times in these lymphatic vessels are consistent with an average velocity of 2.7 p,m/s for lymph flow. Local measurements of lymph flow using FPR indicate that lymph flow rates fluctuate over a range of values (1.4 u 20 /rm/s) with an average of 8 /zm/s. 

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