The Mechanics of Expiration and Some Possible Failures

By: Nick Izzo

Hey folks, today, if you’re interested, you will read about what happens when you breathe out, also known as expiration, as well as some possible mechanical failures that can occur in pulmonary ventilation, breathing. I recently gained this knowledge on what occurs in the body during these failures and expiration in my foundations of kinesiology class with Dr. Pontifax.

Before you exhale it’d probably be wise to inhale. Inhalation is a process within itself that you can find in a blog below this one called Anatomy of the Respiratory System. But during exhalation, your diaphragm is relaxing. Your thorax, between the neck and the abdomen, and your lungs normally resist stretching and will then recoil when the distending force decreases. So this is what happens when the diaphragm relaxes, the tension in the thorax and lungs causes a recoil. More obviously though, the volume of your lungs decreases which then results in the pressure inside your lungs to exceed atmospheric pressure. The end goal is for your body to match the pressure of the atmosphere. This is why breathing changes at different elevations depending on how much oxygen is available.

Here’s breathing explained a little simpler: https://www.youtube.com/watch?v=NSEzg6TBheY

Mechanical mishaps can also occur with breathing. There are some factors that lay within the body such as infections, allergic reactions, and breathing disorders. There are also external factors which is what you will find in this blog including trauma and foreign body airway obstruction. One external factor that can effect breathing is pneumothorax. This occurs when air leaks from the lung into the chest cavity. This is usually the result of blunt force trauma and can then turn into a collapsed lung. Similar to pneumothorax there is also open pneumothorax. This is when an open wound allows air to enter the pleural cavity, a fluid filled space between the chest and lungs, and not into the lungs. This causes major difficulty in breathing. Then there is hemothorax. This occurs when blood leaks into the pleural cavity. Again, it is the result of blunt trauma and again can result in a collapsed lung.

Breathing is a grand old thing, quite essential to life many would say. Much more happens than what the naked eye can see. It’s also very important to avoid a blunt trauma force, if that wasn’t obvious enough, due to the possible consequences if one does occur.

References:

Http://www.youtube.com/channel/UCaa1W1sfZ3xsMFUG3u6IsLg. "How Do We Breathe Animation - How Do The Lungs Work Video - Respiratory System: Process of Breathing." YouTube. YouTube, 09 Nov. 2012. Web. 31 Jan. 2017.

“MSU- KIN 173 – Foundations of Kinesiology – Spring 2017”. Education.msu.edu. N.p., 2017. Web. 31 Jan. 2017.