Parabronchi

Definition

Parabronchi are small, tubular air passages in the lungs of birds that allow for continuous airflow and efficient gas exchange. They are a key component of the avian respiratory system, facilitating high oxygen intake to support flight.

5 Must Know Facts For Your Next Test

1. Parabronchi enable unidirectional airflow through the lungs, enhancing respiratory efficiency.
2. They are part of a highly efficient respiratory system that includes air sacs and allows for nearly constant oxygen absorption.
3. The structure of parabronchi allows for cross-current gas exchange, maximizing oxygen uptake and carbon dioxide removal.
4. Parabronchi are lined with blood capillaries where gas exchange occurs between the air and blood.
5. This unique respiratory adaptation supports the high metabolic demands of flight in birds.

Review Questions

• What is the primary function of parabronchi in avian lungs?
• How do parabronchi contribute to the efficiency of a bird's respiratory system?
• Explain how the structure of parabronchi supports continuous airflow in birds.

Related terms

Air Sacs: Thin-walled structures connected to a bird's lungs that help maintain unidirectional airflow.

Cross-current Exchange: A mechanism where blood flows perpendicular to air flow, enhancing gas exchange efficiency.

Alveoli: Small sac-like structures in mammalian lungs where gas exchange occurs; different from but analogous to parabronchi in birds.