An Amazing Journey: How Young Lungs Develop
By the time you take your first breath, your lungs have already undergone a fascinating transformation. From birth through childhood and on to adulthood, your lungs experience an amazing journey, becoming the hard-working, life-sustaining organs that are so easy to take for granted. To better appreciate these essential organs, let's look at some breathtaking facts about our developing lungs:
- Growth like a tree: While still in the womb, during one of the earliest periods of lung development called the pseudoglandular stage, the lungs grow like a tree, with branches sprouting out from the main left and right trunks. Throughout the pregnancy, these "branches" become more complex. The rate of lung development can vary greatly, and the lungs are among the last organs to fully develop – usually around 37 weeks.
- From fluid to air: While in the womb, lungs are filled with fluid and oxygen is supplied through the umbilical cord. At birth, the lungs undergo their biggest change, when they must quickly start breathing air, to supply the baby with oxygen and expel carbon dioxide. This dramatic change happens just moments after birth.
- Newborn lungs need lubrication: Once the newborn lungs are breathing air, they need something to keep them supple and able to expand and take in air. That's the job of a fatty compound called surfactant. Premature babies sometimes don’t produce enough surfactant and develop respiratory distress syndrome (RDS), which makes it hard for them to breathe. American Lung Association researcher Dr. Mary Ellen Avery was part of the team that discovered surfactant's role in RDS. Now, surfactant can be made artificially and is an effective treatment for babies with RDS.
- An explosion of air sacs: Tiny air sacs (alveoli) inside the lungs do the work of transferring oxygen from the air into the blood, and carbon dioxide out of the blood to exhale back into the air. At birth, a baby only has 50-70 million air sacs. In the first six months, more air sacs develop very rapidly, then continue to develop more slowly until reaching the typical adult number of 300 million. That's an increase of more than 400 percent!
- Bigger and better: Not only do a child's lungs increase in the number of air sacs, they also increase in air capacity – the amount of air their lungs can hold – especially over the first two or three years of development. A healthy child's lungs should continue to grow and increase in volume throughout childhood. At birth, females may have larger airways than males, but at the end of puberty, lung function will be about 25 percent greater in males than in females of identical height.
Protecting Children’s Lungs
Children's lungs take a long time to develop and fully mature. That's why it's important that parents do what they can to protect them from things that can hurt their lung development, like secondhand smoke and air pollution. Here are some things you can do:
- Create a "no smoking zone" around your child. There is evidence that a mother's smoking or her exposure to secondhand smoke during pregnancy can harm the fetus.
- Avoid both indoor and outdoor air pollution as much as possible. Be aware of your daily outdoor air quality and avoid being outdoors during high pollution days. You can use these tips to create healthier air at home and school and also take action to clean up the air we all share.
- Get your flu shot. Influenza (flu) is a serious illness and can even be fatal for children. Make sure you and everyone in your family gets their annual flu shot. And research has shown that the flu shot is safe for pregnant women, so start the vaccination habit early!
- Learn to spot the signs of asthma or other lung issues and talk to your pediatrician if you are concerned about your child's lungs.
Sign up for the latest lung health news sent right to your inbox.
Join more than 500,000 people who receive research updates, inspiring stories, health information and more.