Lead absorbed by inhalation in the body is mainly eliminated through:
**Core Concept**
The elimination of lead absorbed by inhalation involves the kidneys, which excrete the toxic metal through urine. The process involves the chelation of lead ions with sulfhydryl groups of cysteine and glutathione, followed by renal excretion.
**Why the Correct Answer is Right**
The kidneys play a crucial role in eliminating lead from the body. The metal is first bound to the sulfhydryl groups of cysteine and glutathione, which are abundant in the renal tubules. This binding facilitates the excretion of lead through the urine. The kidneys' ability to filter and eliminate lead is critical in reducing its toxic effects on various organs, including the brain, kidneys, and hematopoietic system.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the liver is primarily involved in metabolizing and detoxifying substances, but it is not the main route for lead elimination.
**Option B:** This option is incorrect because the gastrointestinal tract is the primary route of lead absorption, not elimination.
**Option C:** This option is incorrect because the skin is not a significant route for lead elimination.
**Clinical Pearl / High-Yield Fact**
The kidneys are highly susceptible to the toxic effects of lead, which can cause acute kidney injury and chronic kidney disease. This emphasizes the importance of monitoring renal function in patients exposed to lead.
**Correct Answer: D. The kidneys.