Anatomy Respiratory

Put your hand on your chest. Breathe in and out. Your chest rises and falls because of your lungs, which fill up like balloons as you breathe in. Like a balloon deflating, your lungs release air when you breathe out. 

Each person has 2 lungs. The right lung is larger than the left. The left lung is smaller so that there is enough room in the chest for the heart, which is also on the left-hand side of the body.

The lungs are the large pink organs you see. Air is drawn into the lungs through the nose, mouth, and trachea. The lungs expand, process the oxygen in the air, and oxygenate the blood in a process called respiration.

The left lung is divided into 2 pieces or sections called lobes. It is longer and narrower than the right lung. However, it is smaller because it is located near the heart.

The right lung is larger than the left and has 3 lobes. The right lung is shorter, but wider than the left lung, and it occupies more space in the chest. Both lungs perform the same functions.

Powered by the lungs, the respiratory system also includes the nose, mouth, and trachea. The nose and mouth allow passage of air in and out of the body. The trachea leads to long, thin tubes called bronchi which branch out in the lungs. 

The lungs are full of tiny sacs called alveoli. Within the alveoli, blood flows to get rid of carbon dioxide and get charged with oxygen. The blood then leaves the lungs to carry oxygen all over the body.

Our mouths and noses are specially designed to take air into the body. Before entering the trachea, the air goes through sinuses, where the body makes sure the air is the correct temperature and humidity for our bodies.

After passing through the sinuses, air goes through the trachea, which leads to the bronchi, 2 tubes that connect to the lungs. Bronchi are lined with small hairs and sticky mucus that catch any dust or germs. When we cough or sneeze, mucus is expelled.

The bronchi lead to bronchioles which are tiny, tiny tubes within the lungs. There are about 30,000 bronchioles in each lung. They lead to alveoli which are like tiny balloons. The exchange of oxygen and carbon dioxide takes place at the alveoli.

The lungs work with the heart to make sure our bodies have enough oxygen. The heart pumps blood that doesn’t have enough oxygen into the lungs, where it reaches the alveoli.

 There, the blood leaves carbon dioxide and picks up oxygen. Then, the blood is returned to the heart where it is pumped out to the rest of the body.

The heart is located on the left-hand side of the body and is nestled between the two lungs. This is convenient because the heart must pump incoming blood through the lungs and then back out to the body.

The heart receives blood that is low in oxygen, shown in blue. The heart pumps this blood into tiny vessels and capillaries in the lungs. The capillaries travel around the alveoli.

The alveoli fill up with air like tiny balloons. You can see capillaries full of deoxygenated blood around the alveoli. As blood becomes filled with oxygen, it turns red, known as respiration. Once oxygenated, blood returns to the heart where it is pumped out.

The veins carry blood to the heart. In this image, the veins are blue as they lack oxygen. Arteries carry blood that has been oxygenated in the lungs back out to the body. The heart pumps the blood.

The trachea, or windpipe, measures 1 inch wide and 4-6 inches long. It connects the mouth and nose to the lungs so that air may flow through. It is made of cartilage, the same material as on the end of your nose.

At the top end of the trachea is the larynx, which also helps with breathing and speaking. The epiglottis is a small flap of tissue that covers the trachea when swallowing so food doesn’t accidentally go into this tube.

Here, we can see the very end of the trachea where it divides into the bronchi. Each of these openings leads to one of the lungs. The trachea itself is smooth on the inside and also contains muscle which contracts when coughing occurs.

The bronchi are lined with small hairs and sticky mucus which catch any dust or germs that enter the lungs. It is important to keep such debris out of the respiratory system. 

The lungs are full of intricately connected bronchioles and alveoli. Branching throughout the lungs by the thousands, the alveoli make the lungs spongy and soft. When breathing in, each alveolus puffs out like a balloon, causing the whole lung to grow in size.

Look at one of the alveoli up close. Notice how the capillaries stretch over the alveolus becoming very thin, so thin that the blood cells in the veins may make exchanges with the air on the other side of the membrane, inside the alveolus. 

Smoking cigarettes or inhaling smoke of any kind is very bad for the lungs. Many functions that the lungs perform are harmed by smoking.

For example, the bronchi produce more mucus in smokers to catch all of the dust being inhaled, so smokers often have bad coughs. Lung tissue, or the cells that make up the lungs, die due to smoking. Cancer in the lungs may also be caused by smoking.

Healthy lungs are a pink or red color. The lungs of people who have been smoking for many years turn black due to the chemicals from the cigarettes which stick to their lungs. 

Here we can observe an example of healthy lung tissue. Notice that the bronchioles and alveoli are pink. This means that they are able to do their jobs and functioning well.

Although the lungs try to protect the body from harmful dust and debris entering it, when we smoke, the carbon from the smoke stays in the lungs and makes holes in them. This means the lungs don’t function as well as normally.