Lymph--Circulation.

Xenopus laevis transgenic lines and their use in the study of lymph heart musculature development

Lymph hearts are pulsatile organs present in lower vertebrates that propel lymph throughout the body and into the venous system, assisting in the maintenance of fluid homeostasis. In organisms such as frogs, several pairs of lymph hearts develop amidst the somites during the early tadpole stages. Due to the unique structure and function of lymph heart musculature—exhibiting characteristics of both skeletal and cardiac muscle—the origin of these cells remains highly controversial.