17. Which one of the following structures drains oxygen-depleted blood from the kidneys?
Answer: D
Renal vein drains oxygen-depleted blood from the kidneys.
The renal vein is responsible for draining oxygen-depleted blood from the kidneys, transporting it back to the heart. This is a crucial function in maintaining overall circulatory health and ensuring that deoxygenated blood is efficiently removed from the kidneys.
A) Ureter
The ureter is a tube that carries urine from the kidneys to the bladder. It does not play a role in draining blood; therefore, it is not the correct answer as it does not deal with oxygen-depleted blood.
B) Renal artery
The renal artery carries oxygen-rich blood from the heart to the kidneys for filtration. It is not involved in draining oxygen-depleted blood, making this option incorrect.
C) Urethra
The urethra is the duct through which urine is discharged from the bladder outside the body. Similar to the ureter, it is not involved in blood drainage, hence it is not the correct choice.
D) Renal vein
The renal vein specifically drains oxygen-depleted blood from the kidneys back to the heart. This role is essential for maintaining the proper flow of blood and ensuring that waste products filtered by the kidneys are returned to the circulation for processing.
Conclusion
The renal vein is definitively the correct answer as it directly performs the function of draining oxygen-depleted blood from the kidneys. In contrast, the other options either relate to urine transport or the delivery of oxygen-rich blood, which does not address the question of blood drainage from the kidneys. Thus, only the renal vein fulfills the criteria specified in the question.