Fluid Pumping and Mass Transfer in the Lymphatic System
Date: Wed 4 Nov 2015, 15:00 - 16:00
Location: PP1 Lecture Theatre, People's Palace, Mile End
Prof. James Moore, Imperial College
The lymphatic system has many recognized important roles in normal physiology and in a variety of disease conditions. In addition to returning fluid from interstitial tissue spaces to the blood circulation, it also serves as an important transport route for immune cells. Lymph nodes are important sites for cellular interactions involved in immunity, inflammation and fluid balance. Transport phenomena and/or breakdowns in lymphatic system performance are crucial, or at least involved in, cardiovascular diseases, cancer, obesity and injury resolution. Despite the importance in so many causes of death and disability, little is actually known about transport mechanisms in this obscure system.
We have developed models of lymphatic system pumping based on a multiscale approach, combined with a unique experimental skill set. In addition to the general insight on lymphatic pumping, we have elucidated the phenomena by which the lymphatic system is able to generate negative interstitial tissue pressures while still generating positive fluid flow out of those tissues. This resolves a decades-old mystery of basic physiology. Our results have also identified two physical properties of lymphatic vessel behavior that are crucial for effective pumping. The first is the resistance of lymphatic valves to both forward and reverse flows, and how they switch from the closed to the open position and back. The second is the unique abilities of lymphatic muscle cells (LMC) to contract over a wide range of vessel diameters. Our current experimental and modeling work is focused on quantifying these parameters better?