Visiting Professor of Anatomy ('63) at the University of Minas Gerais Medical School, Belo Horizonte, Brazil, with a travel grant from the Rockefeller Foundation.
The lymphatic system of Bradypus tridactylus†
Article first published online: 3 FEB 2005
Copyright © 1965 Wiley-Liss, Inc.
The Anatomical Record
Volume 153, Issue 2, pages 149–160, October 1965
How to Cite
Azzali, G. and Didio, L. J. A. (1965), The lymphatic system of Bradypus tridactylus. Anat. Rec., 153: 149–160. doi: 10.1002/ar.1091530205
Supported by a grant from the Italian National Council of Research.
- Issue published online: 3 FEB 2005
- Article first published online: 3 FEB 2005
The lymphatic system of the sloth (Bradypus tridactylus) was described after the study of five specimens captured in Brazil. The lymphatic system was injected with Prussian blue suspension and neoprene latex (the latter followed by partial corrosion). The description includes lymph nodes, lymphatic networks, vessels and trunks. The distribution of these structures follows the general pattern of other Xenarthra, namely, Dasypus, Euphractus and Tamandua. However, the following peculiarities were noted: the submandibular, popliteal and posterior mediastinal ll.nn., the abdominothoracic subcutaneous lymphatic collecting vessels, the true principal lymphatic trunks, the cisterna chyli, and the thoracic duct were missing in Bradypus tridactylus. The mesenteric ll.nn. do not fuse and their efferent vessels intermingle with those originating from the cecocolic ll.nn. forming a mesenteric lymphatic plexus. The lymphatic vessels arising from the submucous network of the descending and sigmoid colon are arranged as parallel lamellae similar to those in Dasypus. The efferent collecting vessels from several abdominal organs ultimately empty directly in the inferior vena cava and its trunks of origin and those coming from the bronchial ll.nn. lead to the azygos vein. This feature reminds one of the conditions described in some monkeys. The mesenteric postlymphonodal plexus is well developed and because of the absence of intercalated lymph nodes in the labrinthine circulation it resembles that of amphibia and birds.