The human organ that is similar in function to the nephridium of worms is the kidney.

Here's why:

* Nephridia in worms: Nephridia are excretory organs in worms that filter waste products from the blood and body fluids. They are essentially simple tubes that collect waste, transport it, and then expel it from the body.

* Kidneys in humans: Human kidneys perform a similar function. They filter blood, removing waste products like urea, excess water, and salts. This filtered waste is then collected as urine and excreted from the body.

While the structures are very different (nephridia are simple tubes, kidneys are complex organs), the overall function of removing waste products from the body is shared.