Breathing is essential for our bodies to work properly. It’s how we get the oxygen we need and remove waste gases. There are two types of breathing  → internal and external respiration. These types are like partners, working together to keep us healthy and energized. These processes ensure that our cells receive the oxygen they need to function. This also ensures that carbon dioxide, a waste product, is efficiently removed. Let’s embark on a journey into the world of respiration and unravel its significance.

Overview of Respiration and its Types

Human Respiratory System

Respiration is how our bodies exchange gases with the world around us. It has two parts → internal and external respiration. Internal respiration happens inside our cells, while external respiration happens in our lungs. Here is the overview of two types of Respirations:

  1. Internal Respiration: Inside our bodies, our cells use oxygen to make energy. This process is called internal respiration. Cells also produce waste gas called carbon dioxide, which needs to be removed.
  2. External Respiration: When we breathe in, our lungs take in fresh oxygen from the air. This is external respiration. At the same time, our lungs get rid of the carbon dioxide that our body doesn’t need anymore.

Importance of Internal and External Respiration

Internal respiration helps our cells get the oxygen they need to create energy and carry out their jobs. It also helps remove the waste gas, carbon dioxide. External respiration is the way we take in fresh oxygen from the air and release carbon dioxide. Both types of respiration work together, making sure our cells stay healthy and our bodies keep running smoothly.

Now, let’s discuss Internal Respiration in detail.

Internal Respiration

Internal respiration is a crucial process that happens inside our bodies to keep our cells healthy and full of energy. It’s a bit like the way a power plant generates electricity for a city. Just as the power plant produces energy, our bodies use internal respiration to produce energy for our cells. In this section, we will discuss the definition, processes, and functions of Internal Respiration.

Definition of Internal Respiration

Internal respiration is the process by which our cells take in oxygen and release carbon dioxide. This happens inside the tiny energy factories in our cells called mitochondria. Think of mitochondria as mini-power plants inside our cells, creating energy for everything we do.

Process of Internal Respiration

Internal respiration is the process where our body cells take in oxygen and release carbon dioxide. This happens inside the cells and helps provide energy for our body to work properly. Let’s explore the processes:

Process of Cellular Respiration
  1. Oxygen Delivery: First, the oxygen we breathe in through our lungs enters our bloodstream. Our blood carries this oxygen to all the cells in our body. It’s like a delivery service for oxygen.
  2. Cellular Exchange: Once oxygen-rich blood reaches the cells, the mitochondria use this oxygen to burn up nutrients from the food we eat. This burning process, called cellular respiration, creates energy that our cells use to function properly.
  3. Carbon Dioxide Release: As cells use oxygen to produce energy, they also make waste in the form of carbon dioxide. Just like a car produces exhaust, our cells produce carbon dioxide as a waste product.
  4. Return Journey: The blood then carries this carbon dioxide back to our lungs, where we exhale it when we breathe out.

Functions of Internal Respiration

Internal respiration helps your body get the oxygen it needs from the air you breathe and send out the waste gas, carbon dioxide. It’s like the body’s way of exchanging gases to keep you healthy and energized. Let’s explore the key functions in detail:

  1. Energy Production: The primary purpose of internal respiration is to produce energy. This energy is like the fuel our cells need to perform various tasks, from thinking to running and even sleeping.
  2. Cell Maintenance: Internal respiration not only generates energy but also helps cells get rid of waste. Just like we clean up our homes, cells need to get rid of waste to stay healthy.
  3. Supporting Life: Without internal respiration, our cells wouldn’t get the oxygen they need, and waste products would build up, making us feel sick and tired.

Next, let’s discuss External Respiration in detail.

External Respiration

External respiration is a crucial process that keeps our bodies supplied with the oxygen needed for energy production. This also removes carbon dioxide, a waste product of metabolism. It takes place in the lungs. It is where oxygen from the air we breathe enters our bloodstream and carbon dioxide is released from our blood into the air. In this section, we will discuss the definition, processes, and functions of External Respiration.

Definition of External Respiration

Illustration of External Respiration

External respiration refers to the exchange of gases between the air in our lungs and the blood in the tiny air sacs called alveoli. This process enables the oxygen in the air to move into our blood. While allowing carbon dioxide, a waste product, to leave the blood and be exhaled.

Process of External Respiration

External respiration is when your body takes in oxygen from the air you breathe and releases carbon dioxide into the air. This happens in your lungs where blood picks up oxygen and gets rid of carbon dioxide. Let’s explore the processes:

  1. Inhalation: When we breathe in, the air rich in oxygen enters our lungs. The air travels down the windpipe (trachea) and branches into smaller tubes called bronchi, eventually reaching the alveoli.
  2. Gas Exchange: In the alveoli, oxygen passes through thin walls and into the surrounding network of blood vessels called capillaries. At the same time, carbon dioxide, which has travels in the bloodstream from the body’s cells. Then It moves from the capillaries into the alveoli to be expelled during exhalation.
  3. Oxygen Transport: Oxygen molecules attach to hemoglobin, a protein in red blood cells. Then It carries oxygen through the bloodstream to every part of the body.
  4. Carbon Dioxide Removal: As blood passes through the capillaries near the alveoli, it releases carbon dioxide into the alveoli. Then It is ready to be breathed out.

Functions of External Respiration

External respiration, or breathing, helps us take in oxygen from the air into our lungs and release carbon dioxide, from our body. This process gives our cells the oxygen they need to work properly and keeps our body’s balance in check. Let’s explore the key functions in detail:

  1. Oxygen Supply: The primary function of external respiration is to provide a continuous supply of oxygen to the body’s cells. Oxygen is necessary for cellular respiration, a process that produces energy (in the form of ATP) to fuel various bodily functions.
  2. Carbon Dioxide Disposal: External respiration also plays a vital role in getting rid of carbon dioxide, a waste product of metabolism. If carbon dioxide were to accumulate in the bloodstream, it would lead to a buildup of acidity. This can also disrupt the body’s balance.
  3. Maintaining Homeostasis: By ensuring the proper exchange of gases, external respiration maintains the body’s balance of oxygen and carbon dioxide. This balance is essential for maintaining the body’s pH and overall health.

Next, let’s move to the differentiation between Internal and External Respiration.

Difference between Internal and External Respiration

Breathing isn’t just about air going in and out. It’s also about exchanging important gases in our bodies. Internal and external respiration are the two sides of this gas exchange process. Let’s see how they’re different and what they do.

  1. Oxygen Exchanging Direction: Internal respiration is about oxygen moving from our bloodstream into our cells, where it’s used to make energy. External respiration is about oxygen moving from the air we breathe into our bloodstream.
  2. PO2 (Oxygen Levels): In internal respiration, oxygen levels are higher in the blood and lower in the cells. In external respiration, oxygen levels are higher in the air and lower in the blood.
  3. Carbon Dioxide Exchanging Direction: During internal respiration, carbon dioxide moves from our cells into the blood, so our bodies can get rid of it. In external respiration, carbon dioxide moves from our blood into the air, so we can breathe it out.
  4. PCO2 (Carbon Dioxide Levels): Internal respiration has higher carbon dioxide levels in the cells and lower levels in the blood. External respiration has higher carbon dioxide levels in the blood and lower levels in the air.
  5. Correlation with the External Environment: Internal respiration is all about our cells getting what they need and getting rid of what they don’t. External respiration is how our bodies interact with the outside air, bringing in oxygen and sending out carbon dioxide.

Next, let’s delve into the factors affecting Respiration.

Factors Affecting Respiration

Respiration, the fundamental process of exchanging gases between the body and the environment, is essential for sustaining life. Several factors play a pivotal role in regulating respiration. They also ensure efficient oxygen intake and carbon dioxide elimination. In this section, we will explore common crucial factors that affect respiration.

Surface Area and Diffusion Distance

When we breathe, our body needs to swap gases like → oxygen and carbon dioxide. This happens in our lungs, where there are tiny air sacs called alveoli. These sacs make the exchange of gases really good because they give us a lot of surface area, like having a big space to trade things. Plus, the walls of these sacs are very thin. So, the gases can easily move between them and our blood vessels. This setup helps our body do the gas exchange super efficiently!

Respiratory Diseases and Conditions

Various respiratory diseases and conditions can significantly impact the efficiency of respiration. Let’s take a look at a few common examples:

1. Asthma


Asthma is a chronic respiratory condition characterized by inflammation and narrowing of the airways. This narrowing, known as bronchoconstriction, makes it harder for air to flow in and out of the lungs. Individuals with asthma often experience → wheezing, shortness of breath, and chest tightness. All of these can hinder the normal process of respiration.

2. Chronic Obstructive Pulmonary Disease (COPD)


COPD is a group of progressive lung diseases including → chronic bronchitis and emphysema. These conditions cause the airways to become obstructed and the alveoli to lose their elasticity. As a result, the airways are less efficient at allowing air to pass through. This leads to difficulty in both inhaling and exhaling.

3. Pneumonia


Pneumonia is an infection that causes inflammation in the air sacs of the lungs. This inflammation can lead to the accumulation of fluid and pus, impairing the exchange of gases in the alveoli. Individuals with pneumonia often experience fever, cough, and difficulty breathing.

4. Lung Cancer

Healthy Lung vs Lung Cancer

Lung cancer can develop in any part of the lungs and can interfere with normal respiration. Tumors can obstruct airways, reduce lung capacity, and interfere with the function of surrounding healthy tissue.

Now, let’s discuss the treatments and interventions for Respiratory Diseases.

Treatments and Interventions

Respiratory diseases can make it difficult to breathe and affect our daily lives. Luckily, there are various treatments that doctors use to help people with these conditions.


Medicines are like special helpers that can make you feel better. Doctors might prescribe different types of medicines for respiratory diseases:

  1. Bronchodilators: These help open up your airways, making it easier to breathe. It’s like a door opener for your lungs.
  2. Corticosteroids: These are like firefighters for inflammation in your lungs. They calm down the swelling and help you breathe better.
  3. Antibiotics: If your respiratory disease is caused by bacteria, antibiotics can fight off those bad guys and help you recover.


Inhalers are like magical spray cans that deliver medicine straight to your lungs. You breathe in the medicine, and it goes right where it’s needed to help you breathe more comfortably.

Oxygen Therapy

Sometimes, people need extra oxygen to breathe well. Doctors can give you oxygen through tubes in your nose or a mask. It’s like giving your body an extra boost of fresh air.

Pulmonary Rehabilitation

This is like an exercise class for your lungs. You learn special exercises that make your lungs stronger and help you breathe better. It’s like going to the gym but for your breathing muscles!

Lifestyle Changes

Doctors might suggest changing some things in your life to help your breathing:

  1. Quit Smoking: Smoking is like a villain for your lungs. If you smoke, quitting can make a big difference in how well you can breathe.
  2. Healthy Diet: Eating good foods can keep your body strong and help fight off respiratory diseases.
  3. Stay Active: Moving your body through fun activities can keep your lungs happy and healthy.


In some cases, doctors might need to do surgery to fix a problem in your lungs. They’ll make sure you’re comfortable and safe during the procedure.


Our breathing is like teamwork between internal and external respiration. They work together to give us energy and keep our bodies clean by exchanging oxygen and carbon dioxide. When things go wrong and our breathing gets affected by diseases, doctors have ways to help us feel better.

Medicines, staying away from triggers, and sometimes special machines are there to support us. Taking care of our lungs and following our doctor’s advice is key to staying healthy and active. So, let’s appreciate the amazing job our lungs do and take good care of them!

Further Reading

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