How Do Your Lungs Work?

This is the first part of a two part series (Post 2, What Can Cause it to be Hard to Breathe?)

Your respiratory system is made up of your mouth and nose, a large tube that connects these from your throat to your lungs called the Trachea and your lungs. Your two lungs are the largest part of the respiratory system. They allow your body to get rid of carbon dioxide waste when you exhale and bring in fresh oxygen for your body to use when you inhale.

But how does that actually happen? When you take a breath of air, your body immediately starts to work by warming this air through your sinuses. The air then passes through your voice box (known as your larynx) and into your trachea. The trachea is the large tube that is made up of rings of tough tissue. Your trachea then splits into two tubes called your bronchial tubes and they deliver the air to your right and left lungs.

From here things really get amazing as the air travels through your lungs. The respiratory system gets smaller and smaller until that deep breath you breathed of oxygen molecules arrives at one of millions of air sacs called alveoli. These air sacs contain the capillaries that connect your respiratory system with your vascular and cardiac systems. This connection is what allows your red blood cells to receive fresh oxygen before your blood travels back to the heart. The red blood cells are then sent back out to your body’s organs. They will deliver this oxygen so that your body can function, your heart can beat, your fingers can text and your stomach can break down the meal you just ate. Basically nothing in the body can happen without oxygen.

All of this happens every time you take a breath! But that’s not all- after you take a breath in you have to exhale right? You are able to inhale and exhale because of a muscle known as the diaphragm. After you have taken a breath, your diaphragm relaxes and this is what helps to push the air out of your lungs and back through your respiratory track so you can exhale. Just as you inhaled oxygen, you exhale a substance called carbon dioxide. Your body is made up of cells and as these cells use oxygen to work they create a waste product known as carbon dioxide. When your red blood cells deliver oxygen to a cell they also pick up it’s carbon dioxide waste. When the red blood cell gets back to the capillaries in the lungs it is full of carbon dioxide and it can’t receive any new oxygen. So as your blood travels through the capillaries in your air sac not only is it picking up oxygen but it is passing over its carbon dioxide waste. This allows the red blood cells to pick up those fresh oxygen molecules and it allows your body to get rid of carbon dioxide! Did you usually think of your lungs as part of your body’s system of excretion like your bladder? Pretty amazing!

Ok, so what is that thing they put on my finger at the doctors office? It is called a pulse ox (pulse oximeter) and it gives us an idea of how much oxygen is in your blood. When it says “98%” it means that it is detecting that 98% of your red blood cells’ hemoglobin have oxygen molecules attached to them. And since each red blood cell can carry 270 million hemoglobin that is a great amount of oxygen.