What do we breathe out? Explain with an appropriate example.

Human lungs

Lungs are the organs of respiration in humans. Humans have two lungs, a right lung and a left lung. The right lung consists of three lobes while the left lung is slightly smaller consisting of only two lobes. Together, the lungs contain approximately 2400 km of airways and 300-500 million alveoli, having a total surface area of about 70 square meters in adults — roughly the same area as one side of a tennis court. Furthermore, if all the capillaries that surround the alveoli were unwound and laid end to end, they would extend for about 992 km. Each lung weighs 1.1 kg, therefore making the entire organ about 2.3 kg. The lungs are surrounded by the rib cage. The respiratory zone is the site of gas exchange with the blood. The main job of the lungs is to take oxygen from the atmosphere and put it in the bloodstream, while simultaneously taking carbon dioxide out of the bloodstream and ejecting it into the atmosphere. In addition to providing the body with oxygen-rich blood, lungs are partially responsible for acting as a protective cushion for the heart which they almost completely surround. Keeping our lungs healthy is a relatively easy thing to do: no smoking, avoid environmental pollution wherever possible and to allow movement of fresh air in our homes to provide supplies of oxygen to help our lungs fight off cold-weather bugs.

1. What is the role played by the lungs in our body?

2.What is the weight of an average human lung?

3.Lungs provide our body with _____ blood.

4.Lungs provide protection to which organ?

5.How can we keep our lungs healthy?

6.What is the difference between the right and left lungs?