Each terminal bronchiole gives rise to a number of very thin, irregular walled and vascularised bag like structure called_____

Answer

### Step-by-Step Solution:

1. **Identify the Structure**: The question asks about the structure that arises from each terminal bronchiole. This indicates we are looking for a specific anatomical feature related to the respiratory system.

2. **Understand the Function**: The terminal bronchioles are the last part of the conducting zone of the respiratory system. They lead to structures involved in gas exchange. The question hints at a structure that is thin-walled and vascularized, which is crucial for gas exchange.

3. **Recall the Anatomy**: In the respiratory system, after the terminal bronchioles, the next structures are the alveoli. Alveoli are small, balloon-like structures that are the primary sites for gas exchange in the lungs.

4. **Confirm the Characteristics**: Alveoli are indeed very thin-walled, irregularly shaped, and surrounded by a network of capillaries, making them highly vascularized. This structure allows for efficient diffusion of oxygen and carbon dioxide.

5. **Conclude the Answer**: Therefore, the structure that each terminal bronchiole gives rise to is called **alveoli**.

### Final Answer:
Each terminal bronchiole gives rise to a number of very thin, irregular walled, and vascularized bag-like structures called **alveoli**.

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