The lungs are the central organs of the respiratory system in humans and most other animals, including some snails and a small number of fish. In mammals and most other vertebrates, two lungs are located near the backbone on either side of the heart. Their function in the respiratory system is to extract oxygen from the air and transfer it into the bloodstream, and to release carbon dioxide from the bloodstream into the atmosphere, in a process of gas exchange. The pleurae, which are thin, smooth, and moist, serve to reduce friction between the lungs and chest wall during breathing, allowing for easy and effortless movements of the lungs.

आपण श्वसन करतो तेव्हा नाकावाटे हवा शरीरात घेतो ती हवा ज्या आंतर इंद्रियांच्या मार्फत घेतली जाते त्यांना म्हणतात.आपल्याला दोन फुफ्फुसे असतात.त्या दोन फुफ्फुसांमध्ये किंचित डाव्या बाजूला हृदय असते.डाव्या फुफ्फुसामध्ये खोलगट जागा असते.