Chapter 5 - Microlymphatic Biology

Abstract

This chapter attempts to provide an overview of the current understanding of the lymphatic microcirculation, focusing on the prenodal microlymphatics vessels. It is written from the context of the lymphatic transport system. While the understanding of lymphatic microcirculation lags significantly behind that of the blood microcirculation, the progression of lymphatic biology has entered a phase of renewed interest. Considering the importance of lymphatic muscle to function, that is, the lymphatic system requires phasic and tonic lymphatic contractions to generate and regulate lymph flow, understanding lymphatic muscle is crucial to our overall understanding of lymphatic biology. The precise point in the collecting lymphatic architecture at which muscle cells appear is dependent on the tissue and species. Lymphatic muscle is variably innervated in different tissues and species and neural activation can have different effects on lymphatic muscle contraction depending upon the nerve type. In order to better understand microlymphatic function, an integrated understanding of all of the cells present in the lymphatic vessels needs to be developed. It is hoped that this renewed interest will help further define the regulation of microlymphatic function, including the cellular/molecular mechanisms as well as an integration of these cellular/molecular mechanisms back into overall lymphatic function.