The primary breathing organ of a lion is its lungs. Like all mammals, lions inhale oxygen through their nostrils into their lungs, where oxygen is exchanged for carbon dioxide in the blood.
Lions have a specialized respiratory system that allows them to take in large amounts of air quickly, which is particularly useful when they are exerting themselves during a hunt or during intense physical activity. The diaphragm and intercostal muscles play a crucial role in this process by contracting and expanding to facilitate breathing.
While their lungs are the main organ for respiration, lions also have a unique adaptation in their nasal passages that helps them to detect scents in their environment, which is vital for hunting and social interactions. This combination of lung function and olfactory adaptations makes the respiratory system of lions highly efficient.