1. Your left and right lungs aren’t exactly the same. The lung on the left side of your body is divided into two lobes while the lung on your right side is divided into three. The left lung is also slightly smaller, allowing room for your heart. 2. Human lungs contain almost 1,500 miles of airways and over 300 million alveoli. 3. An average person breathes in around 11,000 litres of air every day.