Question

The diagram given alongside shows a section of a human kidney. Study the diagram carefully and answer the questions that follow:

1. Label the parts numbered 1 to 4.
2. Why does part 2 have a striped appearance?
3. What is the fluid that passes down part 4? Name the main nitrogenous waste present in it.
4. Mention the structural and functional units of kidneys.
5. Name the two major steps in the formation of the fluid mentioned in (c).

Answer 1

1. 1: Cortex
   2: Medulla
   3: Pelvis
   4: Ureter
2. Medulla is composed of a striped substance arranged in several pyramids. Hence, the medulla (b) has a striped appearance.
3. Urine passes down part ‘4’, i.e., the ureter. The main nitrogenous substance present in it is urea.
4. Nephrons are the structural and functional units of the kidneys.
5. The two major steps in the formation of urine are ultrafiltration and selective reabsorption.