James E. Moore Jr.

Séminaire irrégulier
Biomedical Engineering Department, Texas A&M University

The lymphatic system performs many crucial functions in health and is involved in diverse disease states. Lymphatics are responsible for fluid and protein balance, gathering approximately 4 liters/day of interstitial fluid and returning it to the venous system. This system is also part of the primary transport mechanism for the immune system. Lymphedema, a debilitating disease for which there is no known cure, affects a large number of cancer patients who have undergone lymph node dissection as well as trauma victims. The lymphatic system is also the major transport route for metastases of the most deadly cancers. Understanding and modeling the transport of lymph remains a challenge. Tissue pressure is very low, and cannot account for even a small percentage of total lymph flow. There are extrinsic mechanisms such as muscle pumping that aid this task, but much of the work comes from the contraction of lymphatic vessel smooth muscle, with valves preventing backflow. Through a series of in situ and in vitro experiments with lymphatic vessels, we have quantified some of the aspects of the active pumping characteristics of various lymphatic vessels. A complete understanding of lymphatic system pumping will require knowledge of endothelial and smooth muscule cell mechanotransduction, intercellular signaling, and modeling to reveal how these systems work together at the organ level.