Question

In old age, there is decrease in amount of urine output and difficulty in micturition, it is due to:

• A. Increase in number of nephrons
• B. Increase in glomerular filtration
• C. Decrease in number of nephrons
• D. Both a and b

Answer 1

The correct option is C Decrease in number of nephrons

There are approximately 700,000 to 1.8 million functional nephrons per kidney; however, this number progressively decreases due to aging with increased nephrosclerosis. As people age, the arteries supplying the kidneys becomes narrow, thus enough blood is not supplied to the kidneys. Hence, urine output decreases.