Oxygen in demand: How oxygen has shaped vertebrate physiology

Area of Science:

• Comparative physiology
• Vertebrate adaptation
• Oxygen transport

Background:

• Vertebrates possess complex systems to manage oxygen availability during environmental or physiological stress.
• The oxygen transport cascade integrates chemosensory detection, ventilation, cardiac function, and metabolic regulation.
• Maintaining systemic oxygen homeostasis is crucial for survival during hypoxia, exercise, or disease.

Purpose of the Study:

• To review the anatomy, signaling, and mechanics of the oxygen transport cascade.
• To adopt a 'Milsomite' perspective, integrating developmental, physiological, and evolutionary aspects.
• To highlight species with unique adaptations in oxygen transport.

Main Methods:

• Comparative physiological analysis across vertebrate taxa.
• Review of anatomical structures and signaling pathways involved in oxygen sensing and transport.
• Examination of physiological and evolutionary adaptations for oxygen homeostasis.

Main Results:

• The oxygen transport cascade comprises chemosensory detectors, ventilation, cardiac work, and metabolic adjustments.
• These components interact to regulate oxygen delivery and demand across diverse vertebrate species.
• Specific species exhibit remarkable adaptations in multiple cascade components, enabling extreme physiological feats.

Conclusions:

• The comparative approach, championed by Bill Milsom, is vital for understanding vertebrate oxygen transport.
• Studying diverse adaptations reveals the intricate mechanisms maintaining cellular oxygen content.
• Understanding the oxygen transport cascade provides insights into physiological resilience and evolutionary strategies.