Question

The following diagram represents a mammalian kidney tubule (nephron) and its blood supply.
Parts indicated by the guidelines 1 to 8 are as follows:
1. Afferent arteriole from renal artery;
2. Efferent arteriole
3. Bowman's capsule,
4. Glomerulus;
5. Proximal convoluted tubule with blood capillaries;
6. Distal convoluted tubule with blood capillaries;
7. Collecting tubule;
8. U-shaped loop of Henle.
Study the diagram and answer the questions that follow:
Which structure contains the highest concentration of urea?

Answer 1

Afferent arteriole from renal artery (1) contains the highest concentration of urea.