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Date of Award


Document Type

Restricted Thesis: Campus only access

Degree Name

Bachelor of Science



First Advisor

Dr. Gary Radice


Traditionally vertebrate muscle has been classified, based on unique structural characteristics and physiological function, as one of the following types: skeletal, cardiac, or smooth. However, the muscle of the lymph heart, a contractile organ found in amphibians, reptiles, and birds, may have structural and physiological characteristics that challenge this tertiary classification.

The lymphatic system serves the following two functions in all vertebrates. First, it monitors tissue fluid spaces for pathogens. Second, it ensures that excess fluid which has been expelled from the capillaries is reincorporated into the blood of the circulatory system. Amphibians, reptiles, and birds each have an additional organ, the lymph heart, which is a pulsating chamber located where lymph vessels enter veins (Satoh and Nitatori 1980). The lymph heart's primary function is to supplement the lymphatic system's passive movement of lymph by actively pumping lymph from peripheral lymph vessels to nearby veins. Mature Xenopus laevis possess two sets of three lymph hearts located dorsally on either side of the spine in the pelvic girdle.