This question is not as straightforward as it may seem. In reality, the answer is that both of these processes are mechanisms that contribute to respiration. The difference between the two has to do with their location within the respiratory cycle. External respiration happens outside of the body whereas internal respiration takes place in the lungs and other tissues of the body.
External respiration can occur through use of skins on our skin or even a balloon you blow into someone’s face for example, but internal respiration occurs via inhalation and exhalation. When we breathe in and out, oxygen is put into our lungs. Once it enters the blood stream, it splits and goes to the cells. The carbon dioxide is then pushed off with perspiration from the skin or exhalation of breath.
The diagram above shows a very basic overview of how this process works within our body. With external respiration, oxygen can be pulled into the body through mechanisms such as breathing in air through the nose and mouth, or simply inhaling it from oxygen tanks. External respiration also involves perspiration as well because when we sweat, we release water and salt which combine to cause a chemical reaction that removes carbon dioxide from our skin via diffusion. This is also part of external respiration, although it is not a necessary process to follow in order to complete the cycle.
Internal respiration takes place through our lungs and other tissues of the body. Our lungs are basically sacs that hold air so we can fill them with oxygen when they’re empty and release carbon dioxide when they’re full. This is accomplished by our breathing in and out using the diaphragm muscles in our lungs and rib cage , and also through the exhalation of breath from our lungs.
As you can see, the two processes are not mutually exclusive. They both contribute to breathing in and breathing out oxygen within our bodies Under normal circumstances, however, when we breathe in air for external respiration, carbon dioxide is still produced by our body via exhalation during internal respiration
External respiration is still an important part of our bodies’ overall respiratory cycle. It is through external respiration that we are able to get oxygen into our bodies, and internal respiration allows us to release carbon dioxide, something that would be harmful if we simply exhaled it. The two processes are also mutually dependent in the sense that they both contribute to breathing in and breathing out oxygen
However, external respiration is not an absolutely necessary part of the cycle. We can survive for short periods of time without it However, it is regarded as an important part of breathing in and breathing out given that we use it to absorb oxygen from the outside world into our bodies . Without it, the carbon dioxide released through internal respiration would be directly harmful to us
While exhalation is not inherently necessary to complete breathing in and breathing out, it does happen as a result of our lungs being filled with oxygen. In other words, we do exhale carbon dioxide when the cycle returns to inhalation but only because we’ve already breathed it into our lungs. This is one of the instances where external respiration plays a role in completing the cycle.
Internal respiration is definitely necessary, however. We need to breathe air into our bodies in order for us to survive . Thus, it is essential to the cycle. In fact, the only reason that external respiration might not be necessary in a normal day-to-day scenario is because of the effect that inhaling pure oxygen into our bodies has on our breathing in and breathing out. It may be the case that your body is adapted for inhaling pure oxygen and exhaling carbon dioxide at all times, but this would certainly not be a cause of concern. In fact, some people respond very well to having pure oxygen available during periods of exhalation, such as when they’re sleeping or exercising.
That said, external respiration still serves a vital role in our bodies overall respiratory cycles so it is important to be able to recognize what it does if you want to understand how breathing works in general. Ideally, you should consider internal respiration and external respiration both to know as much as possible about how your own respiratory system works.