Kidney of elephants

Area of Science:

• Comparative anatomy
• Mammalian renal physiology
• Elephantid biology

Background:

• Elephants, as an isolated mammalian order, possess kidneys requiring detailed anatomical study.
• Previous investigations have not included detailed portrayals of elephant kidney anatomy, such as pyelograms.

Purpose of the Study:

• To provide a comprehensive anatomical description of the elephant kidney.
• To investigate the structural basis for renal function in elephants.

Main Methods:

• Utilized pyelography and vascular injections with acrylic emulsions.
• Performed dissections under fiberoptic illumination with microscopic examination and measurements.
• Conducted glomerular counts via tissue maceration and cortical fraction analysis.

Main Results:

• Elephant kidneys lack dorsoventral symmetry, featuring 8 +/- 2 lobes with interlobar septa.
• The renal pelvis bifurcates into infundibula supplying each lobe; vascular and nervous structures accompany these.
• Approximately 15 million glomeruli per kidney were counted, with glomerular mass comprising 4.9% of renal parenchyma.

Conclusions:

• Elephant kidneys exhibit structural features suggesting only moderate urine concentrating capacity.
• The renal anatomy shows similarities to manatees but differs from dugongs.