Canine bronchial tree
Watercolour on watercolour paper. Makes sense 😉
Some fun lung facts: Together, the lungs contain approximately 2,400 kilometres of airways and 300 to 500 million alveoli, having a total surface area of about 70 square metres — roughly the same area as one side of a tennis court (obviously depending on what breed of dog, think Chihuahua vs Great Dane). Also, if all of the capillaries that surround the alveoli were unwound and laid end to end, they would extend for about 992 kilometres, which is 100 km MORE than the distance between Sydney and Melbourne.