The ameboid movement exhibited by leucocytes into extravascular spaces is known as  

Options

A. exocytosis
B. pseudopodial movement
C. diapedesis
D. all the above

Answer

To solve the question regarding the ameboid movement exhibited by leucocytes into extravascular spaces, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks about the type of movement that leucocytes (white blood cells) exhibit when they move into extravascular spaces. This movement is characterized by the ability of these cells to change shape and move.

2. **Identify the Options**: The options provided are:
- a) Exocytosis
- b) Pseudopodial movement
- c) Diapedesis
- d) All of the above

3. **Analyze Each Option**:
- **Exocytosis**: This is a process where substances are expelled from a cell through the fusion of a vesicle with the plasma membrane. It does not describe the movement of cells into spaces.
- **Pseudopodial Movement**: This refers to the extension of the cytoplasm to form pseudopodia (false feet), allowing for crawling-like movement. This is a characteristic of amoeboid movement.
- **Diapedesis**: This is the process by which blood cells move through the intact walls of capillaries, typically during inflammation. It describes the movement of leucocytes out of the bloodstream into tissues.
- **All of the Above**: This option suggests that all previous options are correct.

4. **Determine the Correct Answer**:
- While exocytosis is not relevant to the movement of leucocytes, both pseudopodial movement and diapedesis describe aspects of how leucocytes move. However, the specific term that best describes the amoeboid movement of leucocytes into extravascular spaces is **pseudopodial movement**.

5. **Final Answer**: The correct answer is **b) Pseudopodial movement**.