Tubular Excretion (1.7)

Question 1

Where does tubular excretion take place?

Answer 1

It takes place in the proximal and distal tubules of the nephron.

Question 2

Explain the tubular excretion process?

Answer 2

It is almost like reabsorption in reverse. The cells of the tubules remove certain molecules and ions from the blood and actively deposit these into the filtrate. BOTH hydrogen ions and potassium ions move into the filtrate and sodium ions move back into the blood. Water follows the sodium ions by osmosis. More creatinine and uric acid move into the filtrate. Undesirable substances are actively excreted.