Blood which leaves liver and passes towards heart has higher concentration of

Options

A. Bile
B. Oxygen
C. RBCs
D. Urea

Answer

To solve the question regarding the concentration of substances in blood that leaves the liver and passes toward the heart, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Function of the Liver**:
- The liver plays a crucial role in metabolism, including the processing of amino acids and the detoxification of ammonia (NH3), which is a byproduct of amino acid metabolism.

2. **Amino Acid Metabolism**:
- When proteins are broken down, they release amino acids. The liver converts excess amino acids into ammonia, which is toxic to the body.

3. **Conversion of Ammonia to Urea**:
- The liver converts ammonia into urea through a process known as the urea cycle (or ornithine cycle). Urea is much less toxic than ammonia and can be safely transported in the bloodstream.

4. **Blood Composition After Liver Processing**:
- After the liver processes amino acids and converts ammonia to urea, the urea enters the bloodstream. Therefore, the blood leaving the liver contains a higher concentration of urea.

5. **Conclusion**:
- Since the question asks for the substance with a higher concentration in the blood leaving the liver towards the heart, the correct answer is urea.

### Final Answer:
The blood which leaves the liver and passes towards the heart has a higher concentration of **urea**.

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