Difference between Breathing and Respiration

Breathing and Respiration

Breathing and respiration are two completely different but interrelated body processes which assist body organs to function properly.  Breathing is the physical process of exchanging gases whilst respiration is a chemical process which takes place at a cellular level and produces energy.  They have many different characteristics and we will learn about them below.  

What is breathing? 

In physiological terms, breathing could be defined as an action of air or water moving across the surface of a respiratory structure such as gills or lungs to facilitate the exchange of oxygen and carbon dioxide from the environment for a process known as respiration. 

How do we breathe?

The process of breathing starts when you inhale air through your nose or mouth and it travels down the back of your throat and into the windpipe which is divided into many air passages called the bronchial tubes.

The physiological parts involved in breathing are: 

  • Nose and nasal cavity

  • Sinuses

  • Mouth

  • Throat (pharynx) and voice box (larynx)

  • Windpipe (trachea)

  • Diaphragm

  • Lungs

  • Bronchial tubes and bronchioles

  • Air sacs (alveoli)

  • Capillaries

The bronchial tube further subdivides into smaller air passages called bronchioles. At the end of each bronchiole, there are balloon-like air sacs known as alveoli which are surrounded by blood vessels called the capillaries. It is in the alveoli that the inhaled oxygen passes into the blood.  

The oxygen-rich blood then travels to the heart and then it is pumped out to all the cells, tissues and organs of the body. The cells use the oxygen and then carbon dioxide is produced which is again absorbed by the blood and travels to your lungs where it is removed from the body as you exhale.

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Inhalation and exhalation

The chest cavity always has a slight negative pressure which keeps the lungs open. When you inhale, the lung volume increases due to the contraction of the diaphragm and the intercostal muscles which help in expanding the chest cavity. As the volume increases there is a decrease in pressures within the chest cavity which is less than the atmospheric pressure. The pressure gradient between the chest cavity and the atmospheric pressure allows the air to enter the lungs which is inhalation.

In this process, the chest expands out. It should be noted here that the human lungs are elastic and when the lungs are filled with air the tissues of the lung exerts pressure back towards the interior of the lungs. Both inward and outward forces compete to inflate and deflate the lungs at every breath.

As you exhale, the lungs force the air out and the intercostal muscles and the diaphragm relaxes, which increases the pressure within the chest cavity. The air exits the lungs due to the pressure gradient between the chest cavity and the atmosphere. Exhalation is classified as a passive event since there is no muscle contraction to expel the air.

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What is respiration?

Respiration could be defined as a biochemical process in which the cell of an organism obtains energy from oxygen and glucose and in turn releases ATP, carbon dioxide and water. The energy is used for various daily activities such as walking, running, sitting and almost all bodily processes. It plays a vital role in maintaining the functions of our organ system.

Respiration can be classified into two types:

  1. Aerobic respiration

  2. Anaerobic respiration

Aerobic respiration: This process takes place in the presence of oxygen to produce energy. It can be observed in all types of eukaryotic cells. 

Anaerobic respiration: This process takes place in the absence of oxygen and can generally be observed in human muscles cells, prokaryotes and methanogens.

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How is respiration different from breathing?

In general terms, respiration is a chemical process whereas breathing is a chemical process. Both are inter-related but their mechanisms vary. Below we will have a look at the different characteristics between breathing and respiration. 

Respiration vs Breathing

Comparison basis




Breathing is the process of inhaling oxygen from the environment and exhaling carbon dioxide back to it with the help of the lungs.

It is a process where glucose and oxygen are broken down to produce energy which is used for cellular activities.


It is a biophysical voluntary process which happens in two stages i) inhalation and ii) exhalation.

It is a biochemical involuntary process which takes place through i) glycolysis ii) Krebs cycle.

Where does it take place?

It takes place in the lungs or gills.

It takes place in cells.

Energy production

No energy is produced in this process.

Energy is produced in the form of ATP

Cellular activity

Breathing is an extracellular process.

Respiration is an intracellular process.

Enzymes used 

There are no enzymes used in this process. 

Many enzymes play a major role in respiration.

Organs or systems associated: 

It takes place through the respiratory system. 

It takes place in each cell.

FAQ (Frequently Asked Questions)

1. What is the role of breathing in respiration?

Breathing can be referred to as a type of physiological respiration in vertebrates which fulfils the purpose of gas exchange through the lungs. The circulatory system transports these gases to all the organs of an animal.

During inhalation, oxygen is absorbed by the blood in the alveoli in the lungs and it is transported in all living cells. This oxygen is used in the mitochondria for aerobic respiration to produce ATP. The process completes in an event known as oxidative phosphorylation where O2 is the final electron acceptor. Carbon dioxide is also produced in cellular respiration as a result of the oxidation of biomolecules.

So, it can be concluded that the electrons utilised in the ETS or the electron transport system come from the oxygen from the process of inhalation. Therefore, breathing plays a direct role in cellular respiration.

2. Is respiration passive or active?

Cellular respiration is an incredibly complex process which takes place in the mitochondria. It includes the movement of molecules across cell membranes or the movement of electrons from one molecule to another. With the exception of pumping air into the lungs and moving blood, respiration is a completely passive, biochemical process where everything takes place inside a cell without any external assistance.