GED Science TestLife ScienceHard
A medical researcher is developing a new drug that inhibits the reabsorption of water in the kidneys, leading to increased urine output. Which part of the nephron is the drug most likely targeting?
- ABowman's capsule
- BLoop of Henle
- CCollecting duct
- DGlomerulus
Show answer & explanationAnswer & explanation
Correct answer: B. Loop of Henle
The Loop of Henle is crucial for establishing the osmotic gradient in the kidney's medulla, which is essential for the reabsorption of water, particularly in the descending limb. Inhibiting water reabsorption here would significantly increase urine output.
Why the other options are wrong
- A. Bowman's capsule collects the filtrate from the glomerulus, it's not involved in significant water reabsorption.
- C. The collecting duct's water reabsorption is primarily regulated by ADH, and while it reabsorbs water, the Loop of Henle's role in establishing the gradient is more fundamental to the overall process of concentrating urine.
- D. The glomerulus is primarily for filtration, not reabsorption.
Kidney Nephron Function
The nephron is the functional unit of the kidney, responsible for filtering blood, reabsorbing essential substances, and excreting waste and excess water to form urine.
- Filters blood in glomerulus
- Reabsorbs water and solutes in tubules
- Secretes waste products
- Regulates blood volume and pressure
- Maintains electrolyte balance
Memory trick: Filter, Reabsorb, Secrete, Excrete.