Answer
When the kidney "secretes" penicillin , the drug is removed from the blood stream and passed into the tubular fluid.
Work Step by Step
Inthe process of tubular secretion, substances are removed from the blood and passed into the blood stream. Usually, ions in excess in the serum, eg. K+, H+. NH4+ are secreted into tubular fluid. creatinine, urea, and drugs like penicillin are also removed from the blood by tubular secretion and passed into the tubular fluid.
