Re-absorption involves which of the following?

Re-absorption involves which of the following?

• A. Substances are secreted into the urine
• B. Water is reabsorbed; the body determines what is needed and what is not
• C. Waste excreted
• D. Blood filtered into the tubule

Answer: (B)

Reabsorption is the kidney’s process of reclaiming useful substances from the filtrate and returning them to the bloodstream. Water reabsorption is a key part of this, and the amount the body reclaims is regulated to match hydration and needs. Hormones like ADH adjust how permeable the collecting ducts are to water, so the kidneys conserve or excrete water as required. This selective reabsorption explains how the body determines what is needed and what is not, shaping the final urine concentration. The other statements describe different kidney actions: substances being secreted into the urine is secretion, not reabsorption; waste excreted refers to elimination; blood being filtered into the tubule describes filtration, which is the first step before reabsorption occurs.

Reabsorption is the kidney’s process of reclaiming useful substances from the filtrate and returning them to the bloodstream. Water reabsorption is a key part of this, and the amount the body reclaims is regulated to match hydration and needs. Hormones like ADH adjust how permeable the collecting ducts are to water, so the kidneys conserve or excrete water as required. This selective reabsorption explains how the body determines what is needed and what is not, shaping the final urine concentration.

The other statements describe different kidney actions: substances being secreted into the urine is secretion, not reabsorption; waste excreted refers to elimination; blood being filtered into the tubule describes filtration, which is the first step before reabsorption occurs.