The Pathophysiology of the Respiratory System

The respiratory system is one of the most vital systems in the body because it supplies the primary element that keeps everything going which is oxygen.

First, we’ll be going through the anatomy and physiology, the pathophysiology, and the common diseases associated with the lungs. Then, we’ll tackle the two types of respiratory drugs which are categorized as the bronchodilator team and the anti-inflammatory team.

Let’s get into it.

The Inverted Tree

For our anatomy and physiology discussion, think of the lungs as an inverted apple tree.  So, a tree has a stump with branches extending to smaller branches with leaves and apples. Much like the alveoli which are mainly responsible for oxygen exchange, the apples are the end product of the tree.

Parts of the Tree

The bronchi are the tree stumps that break off into bronchioles. The bronchioles, much like the branches, are the distal portions that extend to the leaves and apples which is also known as the alveoli.


There are a couple of things that can go wrong, primarily concerning with an exchange from oxygen to carbon dioxide. Remember, we breathe out carbon dioxide, and oxygen is what we breathe in and is what gets distributed to the various parts of the body.

What are some of the issues that affect the respiratory system?

  1. The blockage caused by allergens and smoking.

These factors are enough to create bronchial obstruction which will prevent oxygen to get into the distal portions of the lungs. If there is a lack of oxygen, the heart will be directly affected because it will compensate for the insufficiency.

  1. Cholinergic effects

This is simply increased mucus production inside the lungs. The presence of thick mucus secretions that builds to the branches of the lungs or inside the alveoli will compromise oxygen exchange. The lungs will become sluggish, and the client will experience coughing and hacking, and will eventually develop an infection.

In severe cases, the alveoli are drowned with too much mucus that oxygen exchange has become nearly impossible. This is what happens to pneumonia.

  1. Chronic obstructive pulmonary disease (COPD)

Emphysema and bronchitis are two types of chronic obstructive pulmonary disease that are primarily caused by chronic smoking. Emphysema is a condition wherein the alveoli are destroyed, causing the trapped air inside the lungs and making it difficult for the client to breathe. Bronchitis, on the other hand, is manifested by the frequent occurrence of a productive cough that also causes difficulty in breathing.

When the alveoli get hard, oxygen exchange will not take place; therefore, there will be a build-up of carbon dioxide that causes a lot of pressure inside the lungs. Infection, for bronchitis, is what causes the increased production of mucus, and without proper expectoration, the secretions worsen.

  1. Asthma

With asthma, the bronchioles are constricted due to a variety of reasons like viral infections, pollution, and allergens. Asthma is a condition wherein there is an inflammation of the bronchi which causes wheezing and shortness of breath.

There are a couple of drugs that can help relieve the production of mucus and relieve constriction – these are the primary goals for respiratory medicines which we will discuss in our next article.

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