Define tracheal intercom.

Explanation

### Step-by-Step Text Solution:

1. **Definition of Tracheal Intercom**: The tracheal intercom refers to the intricate network of tracheae and tracheoles in certain arthropods, such as cockroaches, that facilitates gas exchange.

2. **Understanding the Tracheal System**: The tracheal system, also known as tracheae or tracheal tubes, is a specialized respiratory system in insects. It consists of a series of tubes that transport oxygen directly to the tissues and cells.

3. **Components of the Tracheal System**:
- **Spiracles**: The tracheal system begins with openings called spiracles, which are located on the sides of the insect's body. These spiracles allow air to enter the tracheal system.
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