Function of Respiratory System in a Functionally Strong Body

Hey! Psssttt…

It’s your lungs calling.

How well do you know them?

How well do you know how they work? How your respiratory system functions?

It’s time to lay down some facts.

As you may know from my old posts, building a better body requires strengthening your heart and the systems responsible for efficiently delivering oxygen and nutrients to the working tissues of the body. This is exactly what I talked about a while back when I wrote a post titled How does the Cardiovascular System Work. It explains exactly what your heart goes through as you put your body through varying types of activities.

I want you to start there.

Today is a new day and I want to focus more on the respiratory system and, more specifically, the function of the respiratory system in a functionally strong body. The cardiovascular and respiratory system are actually deeply intertwined, each relying on the other to do its part.

If you haven’t already, I suggest you first take a look at how the cardiovascular system works. Once you see the intricate components that make up the heart and its supporting mediums, you’re ready to see how the function of the respiratory system comes into play.

It’s time to get dirty.

Each and every day, you breathe anywhere from twelve to twenty times per minute – all thanks to your respiratory system.

That’s over 28,000 breaths a day!

The respiratory system itself is composed of a number of intricate components that work together to do one job: deliver oxygen to every cell in every tissue in your body while, at the same time, removing carbon dioxide as a waste product. The oxygen enables the cells in your body to release energy and then use that energy to keep every function in your body operating at optimal levels.

As you know, a functionally strong body is efficient in every aspect, including the respiration process. That being said, the more efficiently your body is capable of delivering oxygen to the working tissues, the better you will be able to perform.

But what is really going on while we breathe?

The respiration process is initiated with a breath. Just like your heart rate, breathing is an involuntary process that is controlled by a region in your brain that we call the medulla.

There is nothing you can do about this process – it just happens.

You can try holding your breath but eventually the excessive carbon dioxide buildup in your blood will force your brain to signal for you to either gasp for air or simply pass out and begin breathing normally. (Please do not try this at home)

The actual breathing process is aided by a rather large, kind of dome-shaped muscle that sits under your lungs – it’s called the diaphragm. Contraction of the diaphragm creates a vacuum that results in air rushing into your lungs. That’s you breathing in. As the diaphragm relaxes, the lungs deflate and you breathe out.

There’s more.

You have intercostal muscles that lie directly between the ribs that help with the overall breathing mechanism. They push and pull the lungs to aid in the expansion and contraction to help you breathe more easily.

When your intensity (or even stress) level increases, breathing becomes more difficult because, all of a sudden, your hard working muscles are demanding more oxygen. Your abdominal muscles come to the rescue. They assist your diaphragm and intercostal muscles to move faster and with greater force allowing your lungs to expand and relax at a faster rate. This is another reason why it’s important to keep your core strong.

An efficient respiratory system uses the nasal cavity (nose) as the optimal point of entrance for outside air to come in. You should always be breathing through your nose. This is because we have hairs, called cilia, that line the inside walls of the cavity – this is all part of our air-cleansing system. If your body is not functionally strong, then you more than likely have a habit of breathing through your mouth. Breathing through your mouth allows harmful substances to enter and possibly cause damage to your lungs.

Our respiratory systems come equipped with shields that prevent harmful substances from entering our lungs. These are the forementioned cilia. But these tiny hairs are not only found in your nasal cavity, they are also found along your air passages. They move in a swaying, or wavy, motion to keep our air passages clean.

A system that is functionally strong has healthy cilia. A system that is not functionally strong (for instance, that of a smoker) has unhealthy, poorly functioning cilia that allow dust, bacteria, viruses and all sorts of allergy-causing substances to enter the lungs and initiate the build up of disease.

If you want to build a better body, get off the cigarette train and keep your cilia functioning properly.

As was discussed in the previous post explaining the cardiovascular system, the actual gas exchange process is quite simple.

The Respiratory System

The pharynx (throat) is there to collect the air that comes in and passes it down to the trachea. The trachea then divides into two main bronchi tubes, each leading to one of the two lungs. The bronchi tubes then further subdivide into bronchioles. At the end of the bronchioles lie the alveoli, the tiny small sacs of air that are the final destination of the air that we breathe in. Note that your body has over 300 million alveoli. The alveoli are surrounded by a mesh of tiny blood vessels called capillaries and it is the interaction of these two components that we rely so heavily on to deliver oxygen to our body. Through diffusion, oxygen is transferred to the blood and is then delivered to the rest of the body. At the same time, carbon dioxide is transferred from the blood to the alveoli where they are then expelled through the air we breathe out.

It is as complicated and as simple as that.

Because I have a fascination for the human body and how it works, I thought I’d end the post by sharing a few interesting facts about the respiratory system that I found here.

Interesting Points about the Function of Respiratory System

Why we yawn: When your body is not getting or processing enough oxygen (for instance, if we’re tired), it compensates by yawning, which is really the act of taking a deep, long breath (you’re probably yawning right now).

Why we sneeze: When you take a breath, the upper airway passages can attract an irritant such as dust or pollen. By sneezing, the high-pressure exhalation pushes the irritant out of the airway.

Why in the world do we hiccup: The answer? Nobody knows!! Hiccups are actually involuntary contractions of the diaphragm, which cause the lungs to contract and air to be pushed out.

Why we cough: Similar to a sneeze, we cough to force irritants or debris out of the air passages. A cough is simply a reflex that forces a quick exhalation. Coughing can also signify infection in the lungs so we cough to try to clear the lungs of mucus.

That’s all for today.

I hope this post has opened your eyes a bit when it comes to understanding the importance of having a healthy respiratory system. If you have any questions or comments with regards to the function of respiratory system, please leave them in the comment section below!

Mitchell - Home Fitness Manual - December 5, 2011


You’ve hit the hammer right on the head. How can someone reach their fitness goals if they don’t ever really take strengthening the respiratory system into account?

One thing I’d like to highlight is training to increase VO2 max is beneficial because as you build your endurance, the heart and muscles get better at using the oxygen-rich blood issued to them. Stronger and faster…who doesn’t want that?


    Test - December 6, 2011

    Hey Mitchell thanks for stopping by. You’re exactly right. Through regular and strategic cardiovascular training, you can strengthen your cardiovascular and respiratory systems. Aside from training, you can avoid things like smoking to maintain healthy cilia; you can also strengthen your abdominals to aid in the breathing mechanism. These are all things to optimize the functions of your systems designed to deliver oxygen and nutrients to the body.

Tony - Coach Calorie - December 6, 2011

Great post Srdjan. Place more focus on the respiratory system and improving its VO2 max. The more oxygen we can get into our body, the more fatty acids we can metabolize.

    Test - December 7, 2011

    That’s essentially what it comes down to Tony – metabolizing those fatty acids. Thanks for stopping by!

Alykhan - Fitness Breakout - December 6, 2011


Great post. It’s important to understand the respiratory system because how well it functions is essentially the fundamental measure of how fit a person is.


    Test - December 7, 2011

    I think the combined function of the respiratory system and cardiovascular system is the fundamental measure of fitness.

Ahmed - December 7, 2011

It’s always interesting to learn about the different systems of the body and how they interact with the organs, really allows for you to get a better understanding of how workouts/diets effect us. Thanks for this one Srdjan!

    Test - December 7, 2011

    No problem Ahmed. I think it’s important to get a deeper understanding of how the body works to be able to design more effective training regimens. I’m glad you enjoyed it 🙂

Josh - October 10, 2012

Amazing post! Never knew that was what yawning was all about, I heard it was something to do with when we were cavemen or something!

Also surprised to learn that we only take 12 – 20 breaths a minute. I’d have expected more than that, and I’m not even unfit!

    Test - October 11, 2012

    Hey Josh, the fitter you are the lower your resting heart rate and the fewer breaths you need to bring in the necessary oxygen. Thanks for your comment!

Rob - October 22, 2014

Hi Srdjan,

Nice detailed post. One thing I found interesting was that you mentioned about yawning. I heard and have experienced that I sometimes yawn when I’m not tired like before a race. I think it’s a way to increase the amount of oxygen because I am preparing for a lot of exertion and I’m nervous, more tense and therefore need more oxygen.

Just thought I’d share that and see if other people have the same reaction in those nervous situations?


David - September 20, 2016

Morning Srdjan,

Nice bit of work. I find that like Rob Yawn when I get nervous. Weird. Funny reaction and people wonder what’s going on when you’re yawning before an important speech or race…Haha. I try to cover it up then it just looks like I’m flaring my nostrils!

Keep up the good work

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