Select the correct statement(s) about lymphatic system from the following.
Lymphatic system returns the excess tissue fluid back to blood.
Lymph vessels contain no valves.
The lymph moves with pumping of heart.
Lymph also has double circulation like heart.

Options

A. Only I
B. I and II
C. II and III
D. All of these

Answer

To solve the question regarding the lymphatic system, we will analyze each statement provided and determine its correctness.

### Step-by-Step Solution:

1. **Statement 1: Lymphatic system returns the excess tissue fluid back to blood.**
- This statement is **correct**. The primary function of the lymphatic system is to return excess interstitial fluid (tissue fluid) back to the bloodstream, which helps maintain fluid balance in the body.

2. **Statement 2: Lymph vessels contain no valves.**
- This statement is **incorrect**. Lymph vessels do contain valves. These valves are essential as they prevent the backflow of lymph, ensuring that it flows in one direction towards the heart.

3. **Statement 3: The lymph moves with pumping of heart.**
- This statement is **incorrect**. Unlike blood, which is pumped by the heart, lymph does not have a central pump. Instead, it moves through lymphatic vessels primarily due to the contraction of surrounding skeletal muscles and the presence of valves that prevent backflow.

4. **Statement 4: Lymph also has double circulation like heart.**
- This statement is **incorrect**. The lymphatic system does not have a double circulation like the cardiovascular system. The lymphatic system is a one-way system that transports lymph from tissues back to the bloodstream, without a central pump like the heart.

### Conclusion:
The only correct statement about the lymphatic system is:
- **Statement 1: Lymphatic system returns the excess tissue fluid back to blood.**

Thus, the answer is **Option A**.

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