The renal columns of Bertin are extensions of the ...... into the renal medulla.

The notch on the medial side of the kidney is known as the ........

The Loop of Henle is concerned with which of the following systems?

State the location of the kidneys.

Which of the following blood vessels contains the minimum concentration of urea in the blood?

The figure shows the human urinary system with structures labelled $A$ to $D$. Select the option which correctly identifies them and gives their characteristics and/or functions.