Morphological aspects of the superficial lymph nodes of Myrmecophaga tridactyla

ABSTRACT

Background: The giant anteater is a Xenarthra of the Myrmecophagidae family. It is classified in Brazil as vulnerablespecie, however, in Rio de Janeiro and Rio Grande do Sul it is probably extinct. In an attempt to contribute to the preservation of the species, many injured animals are referred for treatment and rehabilitation, but the lack of information aboutmorphology may hinder a more efficient clinical-surgical approach. The knowledge on the topography, dimensions andmorphology of lymph nodes of a given species is essential for medical practice. The aim of this study was to identify anddescribe the general morphology of the superficial lymph nodes of Myrmecophaga tridactyla.Materials, Methods & Results: Ten cadavers of adult Myrmecophaga tridactyla were used in this study. They were fixedand preserved with 10% formaldehyde solution and dissected throughout their length to locate their superficial lymphnodes. Lymph nodes of each center were removed for mesoscopic analysis. Measurements of width, length and thicknesswere obtained by a digital caliper. The superficial lymph nodes observed in the head were the mandibular and the intermandibular, while in the neck were identified superficial cervical and deep cervical lymph nodes. In the thoracic limbs,the axillary and the axillary accessory lymph nodes were present. In the pelvic limbs just one lymph node, the femoral,was observed, located in the thick subcutaneous fascia of the medial surface of the thigh. The main anatomical differencesfound in the lymph nodes of M. tridactyla are the absence of parotid, popliteal and subiliac lymph nodes and the presenceof intermandibular lymph nodes and the developed femoral lymph nodes, which are unique in the pelvic limbs of this species. Moreover, some superficial lymph nodes were formed by several small lymph nodes, forming clusters, as observedin the proper and accessory axillary and femoral...