_______ is the ' U ' shaped structure in nephron.

Nephron:

1. Nephron is the functional unit present in the kidneys.
2. There are millions of nephrons that help in the filtration of blood which consists of a cup-shaped structure with a long tube attached to it.

Henle's loop:

1. Henle's loop is a U-shaped long portion of the tubule structure of a nephron that helps in the conduction of urine.
2. The main function of this structure is to reabsorb water and sodium chloride (NaCl) from urine.

Final answer:

Henle's loop is the ' U ' shaped structure in the nephron.