EDTA injected into muscles combines with `Ca^(2+)` and 

Options

A. Stops contraction
B. Causes contraction
C. Slow down contraction
D. None of the above.

Answer

**Step-by-Step Solution:**

1. **Understanding EDTA**: EDTA (Ethylenediaminetetraacetic acid) is a chelating agent. This means it has the ability to bind metal ions, such as calcium (Ca²⁺), magnesium (Mg²⁺), and iron (Fe²⁺).

2. **Role of Calcium in Muscle Contraction**: Calcium ions (Ca²⁺) play a crucial role in muscle contraction. When a muscle is stimulated, calcium ions are released, which interact with proteins in the muscle fibers to enable contraction.

3. **Effect of EDTA on Calcium**: When EDTA is injected into the muscles, it binds to the calcium ions present. This binding effectively reduces the availability of calcium ions that are necessary for muscle contraction.

4. **Resulting Effect on Muscle Contraction**: Because EDTA binds to calcium and prevents it from interacting with the muscle proteins, it leads to a cessation of muscle contraction. In other words, the muscles become paralyzed due to the lack of available calcium ions.

5. **Conclusion**: Therefore, the correct answer to the question is that EDTA injected into muscles combines with Ca²⁺ and stops contraction.

**Final Answer**: EDTA injected into muscles combines with Ca²⁺ and stops contraction.

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