Use the words inspiration and expiration to describe the part of the breathing cycle that occurs as a result of each of the following:
c. The pressure within the lungs is higher than that of the atmosphere.

Question

Use the words inspiration and expiration to describe the part of the breathing cycle that occurs as a result of each of the following:

c. The pressure within the lungs is higher than that of the atmosphere.

Accepted Answer

Welcome back everyone. What is the term used to describe the phase of the breathing cycle when air is expelled from the lungs? Choice A states, inspiration, choice, B states, expiration and choice. Choice C states both. So we're going to begin by defining our steps for the process of inspiration, which is where we would be inhaling a breath. So in our first step of inspiration, our diaphragm contracts in our second stage of inspiration, we would have an increase in volume of our lungs which will expand along with our thoracic cavity and rib cage. In step three of inspiration, we want to recall Boyle's law which states that. So writing out Boyle's law will state that pressure is inversely proportional to volume. And from this law, we can interpret that a decreased pressure of our lungs compared to the pressure of our atmosphere, which is greater will cause for step five of inspiration, air to flow into our lungs because air would flow from high to low areas of pressure or from high areas of pressure to low. So now with our process of inspiration outlined, let's recall our process of expiration now where we would exhale a breath due to relaxation. In our first step of exploration, we would have a contract or rather a relaxation of our diaphragm and rip cage. So we'll draw a downward arrow for diaphragm in step two of expiration. Because of this relaxation, our thoracic cavity and volume of our lungs will decrease. So we have a decreased volume in our lungs plus thoracic cavity in step three of expiration, we would again consider Boyle's law where pressure is inversely proportional to volume. Now, with a lower volume in our lungs. For step four, we have a greater pressure within our lungs more so than the atmosphere. And so thus, air would flow from high to low pressure. So air flows outside of our lungs. So that is step five here and that then completes the process of expiration. So going back to our prompt, if air is expelled from the lungs, then we would rule out choice A which states that we would have inspiration occur because that is when air is flowing inside of the lungs. And that would also allow us to rule out choice C which leaves us with choice B, confirming that expiration is the process of when air is expelled out from the lungs. So be expiration is our final answer. I hope that this made sense and let us know if you have any questions.

Use the words inspiration and expiration to describe the part of the breathing cycle that occurs as a result of each of the following:
c. The pressure within the lungs is higher than that of the atmosphere.

Verified video answer for a similar problem:

Key Concepts

Inspiration

Expiration

Pressure Gradient