Spiracles.

Definition

Spiracles are small external openings that allow air to enter the respiratory system of certain arthropods. They play a crucial role in gas exchange and are found on the exoskeleton.

5 Must Know Facts For Your Next Test

1. Spiracles are commonly found in insects, arachnids, and some myriapods.
2. Insects typically have paired spiracles located on the thorax and abdomen.
3. Spiracles can open and close to regulate water loss and gas exchange.
4. Tracheae connect to spiracles internally to distribute oxygen throughout the body.
5. Some aquatic arthropods have modified spiracles for breathing underwater.

Review Questions

• What is the primary function of spiracles in arthropods?
• How do spiracles help prevent desiccation in terrestrial arthropods?
• In what way are spiracles connected to an insect's internal respiratory system?

Related terms

Tracheae: Tubes that carry oxygen from spiracles to tissues in arthropods.

Exoskeleton: A rigid external covering that provides structure and protection for arthropods.

Book Lungs: Respiratory organs used by some arachnids, consisting of stacked plates within an internal chamber.