Our Lungs

 This week we are looking at our lungs which are two spongy organs in the chest that help us breathe. When we inhale, air travels through the nose or mouth, down the windpipe and into branching tubes inside the lungs. Tiny air sacs called alveoli move oxygen into the bloodstream, while carbon dioxide—a waste gas—moves out of the blood to be exhaled. The diaphragm, a strong muscle beneath the lungs, contracts and relaxes to draw air in and push it out. Healthy lungs support every part of the body, so regular exercise, avoiding smoke and breathing clean air can help protect them.

They are protective by the rib cage which is a protective framework of bones around the chest. It is made up of the ribs, the breastbone and part of the spine. The ribs help shield the lungs and heart from injury, while the muscles between them assist breathing by allowing the chest to expand when we inhale and become smaller when we exhale.

Inside the lungs, the windpipe divides into two main tubes called bronchi, one leading to each lung. These branch again and again into smaller tubes called bronchioles, like the branches of an upside-down tree. At their ends are millions of tiny air sacs called alveoli, surrounded by very small blood vessels called capillaries. Their thin walls allow oxygen to pass into the blood and carbon dioxide to pass out. Soft, stretchy tissue helps the lungs expand and spring back with every breath.

The two lungs are not exactly the same. The right lung is larger and has three sections, called lobes. The left lung is smaller and has two lobes because it shares space with the heart. It also has a small, curved area called the cardiac notch, where the heart sits.