How human respiratory system works?

Respiration is a process by which the body inhales oxygen into the body while exhaling carbon dioxide into the air.

In respiration, an organism intakes oxygen through the nose and exhales carbon dioxide through the same organ.

The red blood cells pick oxygen and transport it throughout the body over blood vessels.

The lungs are the principal organs of the respiratory system.

Respiration is a vital process as it enables the organism to breathe and live.

Without respiration, a person or an animal will die.

The process of respiration varies across species – whether animals or fish.

The respiration process remains different in different environments.

While humans, birds, and animals breathe in oxygen from the air, fishes filter oxygen from the water through their gills.

But, respiration remains evident among all living things. 

The basic respiratory organs

Every animal contains some basic respiratory organs that function in harmony to keep it alive.

This article will discuss the rudimentary respiratory organs in human beings and the way they function.

The entire respiratory system comprises of the following organs – 

1. The nose.

2. The mouth.

3. Pharynx

4. Larynx

5. Lungs

6. Diaphragm

Let us follow the individual role of these organs in some detail and learn about their importance of these organs. 

1. The nose 

The nasal cavity or the nose filters the inhaled air as it warms and moisturizes it.

The tiny hairs present in the nose and the mucus that comes from the cells entrap the minute particles suspended in the air.

These hairs prevent the particles from entering the lungs.

Normal breathing occurs through the nose.

2. The mouth 

The air breathed in through the mouth becomes moistened but is not filtered.

The meeting point of the mouth and the nasal cavity lies at the throat or pharynx.

The mouth acts as a secondary opening to the respiratory tract. If the nose fails to inhale or exhale air due to some obstruction, then the mouth takes its place.

The process is also known as "mouth breathing."  

3. Pharynx 

After the air crosses over the nasal cavity, it leads into a long tube called the pharynx. Air and food can both pass through this pharynx.

4. Larynx 

The “voice box” or the larynx lies underneath the pharynx.

The vocal voice originates from this "larynx."

The sound is produced as air in the lungs passes over the thin tissues present in the larynx.

5. Windpipe or trachea

The trachea or the windpipe is a long tube that runs down into the lungs and splits into the left and right bronchi.

Each of these bronchi branches out further as smaller bronchioles within each of the lungs.

The presence of the epiglottis – a small flap on the trachea covers it during food or drink consumption.

An "involuntary muscle" controls this epiglottis as it prevents foods from entering inside the windpipe or lungs.

The bronchioles end up in the alveoli.

These alveoli are tiny sacs that are found at the end of the bronchioles. The alveoli appear like a bunch of grapes.

It is in the alveoli where the exchange of carbon dioxide with oxygen takes place.

The oxygen is added into the blood while the carbon dioxide is removed from the blood.

A simple diffusion enables the exchange of these gases between the alveoli and the blood.     

6. Lungs 

The right lung is separated into three sections or lobes. The lobes appear like balloons made of sponge-type tissues.

The left lung contains two lobes. Pleura consists of two membranes with one folded and the other continuous.

The pleura separates the lung from the chest wall and surrounds the individual lobes in the lungs.

7. Diaphragm

 It is a muscle sheet that spreads across the bottom portion of the rib cage.

The contraction of the diaphragm enlarges the volume of the chest as the lungs take the air inside.

The relaxation of this diaphragm reduces the chest volume as the air is pushed out from the lungs.  

During inhalation, the diaphragm lowers down to the abdomen while the ribs are pulled outward and upward with the rib muscles.

The chest cavity enlarges in size that pulls in air from the mouth and the nose.

The process of respiration in the human body

Students must remember that the process of respiration varies according to the species.

Plants, animals, birds, and fish follow respiration in their unique and different ways.

Even insects or amphibians respire differently and uniquely. However, the human body processes respiration in the following way -

Oxygen from the air is inhaled through the nose into the lungs for filtration.

Pure oxygen is applied to the blood that transmits the gas into a different part of the body to function.

The hemoglobin, present in the red blood cells or RBCs, picks up the oxygen and delivers it to the heart.

This cardiac organ pumps the oxygen to the whole body through the arteries to feed the tissues in the body.

The minute capillaries, present in the body's tissues, free the oxygen from the red blood cells' hemoglobin and transfer it into the cells.

The “residual cellular waste” or carbon dioxide moves out from the cells and enters the capillaries.

A significant proportion of the carbon dioxide gas dissolves within the plasma that is present in the blood.

The carbon dioxide-enriched blood returns into the heart through the veins.

The "impure carbon dioxide-rich" blood is pumped back to the lungs.

The waste gas – carbon dioxide passes through the alveoli for exhalation.     

Respiration is essential as it supports the life of an organism.

Animals and birds breathe in a different way than fish.

But, respiration plays a vital role in the survival and existence of all the creatures in Nature.

Plants also need air to survive. However, as creatures consume oxygen and breathe out carbon dioxide, plants suck in carbon dioxide and give out oxygen.

Such a give-and-take system of inhalation and exhalation between plants and animals benefits ‘Nature’ itself.