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Updated: Aug 30, 2026

Image Acquisition Method for the Sonographic Assessment of the Inferior Vena Cava
Published on: January 13, 2023
Anatomy of the crocodilian spinal vein
Kevin C Zippel1, Harvey B Lillywhite, Christopher R J Mladinich
1Department of Zoology, University of Florida, Gainesville, FL 32611, USA. ZippelK@zoo.ci.detroit.mi.us
Abstract:
The crocodilian spinal vein is remarkably robust yet historically overlooked. Using corrosion casting, we describe the anatomy of this vessel and its connections with the caval and hepatic venous systems in representatives from four crocodilian genera. The spinal vein arises from an enlarged occipital sinus over the medulla and extends the entire length of the vertebral column. Unlike in squamate reptiles, the spinal vein is single (nonplexiform), voluminous, and situated dorsal to the spinal cord, and plexi lateral to the cord span between emerging intercostal veins. The connections with the other venous systems are otherwise similar to those in other tetrapods. The overall anatomy of this vessel and its abundant connections with the other venous systems indicate it likely plays a primary role in returning blood to the heart from all parts of the body. Preliminary studies of function suggest that this vessel could also play an adaptive role during basking and diving.
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