Inspired by the artwork of Frank Netter and my experiences in the gross anatomy lab, this Daily Doodle highlights the anatomy and vasculature of the Left Kidney, which is one of the unique areas of asymmetry in the body.

The left gonadal vein (testicular/ovarian vein) drains into the left renal vein while on the right, it drains directly into the inferior vena cava. Why is this important? In men, the majority of idiopathic varicoceles occur on the left side because of this difference in drainage of testicular veins. The Left testicular vein drains into the renal vein at an acute angle (90-degrees), which results in higher pressure and back-flow resulting in enlargement of the left scrotal veins. The Right testicular vein drains directly into the inferior vena cava at less than 90-degree angle and since the inferior vena cava is significantly larger in diameter than the renal vein, the pressure is significantly less.

Another asymmetrical feature to note about the kidneys is that the left kidney sits slightly higher than the right kidney which is not demonstrated in this doodle.

References

1. F. Netter, “Atlass of Human Anatomy”. 4th Edition. Saunders. 2006.
2. R. Drake, W. Vogl, A. Mitchell, “Gray’s Anatomy for Students”. Churchill Livingstone. Philadelphia, USA. 2005

11-12-10: “Vasculature of Left Kidney” Medical Daily Doodle by Michiko Maruyama