The Human Respiratory System and Its Functions
In this simple and easy-to-understand article, we discuss the basics of The
Human Respiratory System and Its Functions. This guide is specially designed
for aspiring Pharmaceutical Sales Representatives who are looking to build a
strong foundation as they step into this profession.
Diagram: Respiratory system diagram
Here, you will learn how the nose, lungs, and the entire breathing process
work together as a complete system. The explanations are kept very clear and
supported with diagrams, so that anyone—even beginners—can easily understand
the concepts without confusion.
Table of contents: The Human Respiratory System and Its Functions
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The Human Respiratory System and Its Functions
To understand The Human Respiratory System and Its Functions, focus on the
pathway of air in the lungs. For example, air enters through the nose,
passes down the trachea, and reaches the lungs, where oxygen mixes with
the blood and carbon dioxide is released.
This ongoing gas exchange process is what provides energy to the body. For
Pharmaceutical Sales Representatives, having a clear knowledge of these
basic processes is important, because it helps them understand how
respiratory drugs work and allows them to give better detailing to
doctors.
What is Respiratory System?
Respiratory System is a group of organ which carry oxygen to the bloodstream
& eliminate carbon dioxide from the blood.
What is Respiration?
Respiration
is a physiological process which involves transport of oxygen from the
atmosphere to the body cell for oxidation of the ingested food material and
elimination of carbon dioxide.
Phases of Respiration
Respiration has following two phases:
- Inspiration (Active process): Intake of air into the lungs. Its duration is 2 sec.
- Expiration (Passive process): Output of air from lungs. Its duration is 3 sec.
Diagram: Phases of Respiration diagram
Different Part of Respiratory System
| UPPER RESPIRATORY TRACT | LOWER RESPIRATORY TRACT |
|---|---|
| Mouth | Trachea (Windpipe) |
| Nose, Sinuses and Smell | Lungs |
| Maxillary Sinus | Left Lower Lobe of Lung |
| Opening of Maxillary Sinus | Left Main Bronchus (Primary) |
| Ethmoid Sinus | Left Upper Lobe of Lung |
| Frontal Sinus | Lingula of Lung |
| Nasopharynx | Right Lower Lobe of Lung |
| Oropharynx | Right Main Bronchus (Primary) |
| Laryngopharynx | Right Middle Lobe of Lung |
| Larynx | Right Upper Lobe of Lung |
| Arytenoid Cartilage | Terminal Bronchi and Alveoli |
| Corniculate Cartilage | - |
| Cricoid Cartilage | - |
| Cricothyroid Joint | - |
| Cricothyroid Ligament | - |
| Epiglottis | - |
| Thyrohyoid Membrane | - |
| Thyroid Cartilage | - |
Air enters the body through the nose, is warmed, filtered, and passed
through the nasal cavity. Air passes the pharynx (which has
the epiglottis that prevents food from entering the
trachea). The upper part of the trachea contains the Larynx.
The vocal cords are two bands of tissue that extend across the
opening of the larynx.
After passing the larynx, the air moves into the bronchi that carry air in
and out of the lungs.
Bronchi branch into smaller and smaller tubes known as bronchioles.
Bronchioles terminate in grape-like sac clusters known as alveoli. Alveoli
are ser surrounded by a network of thin-walled capillaries.
Diagram: Different part of Respiratory system diagram
The lungs are large, lobed, paired organs in the chest (also known as the
thoracic cavity). Thin sheets of epithelium (pleura) separate the inside of
the chest cavity from the outer surface of the lungs. The bottom of the
thoracic cavity is formed by the diaphragm.
What is Ventilation?
Ventilation is the mechanics of breathing in and out. When we inhale,
muscles in the chest wall contract, lifting the ribs and pulling them
outward. The diaphragm at this time moves downward enlarging the chest
cavity. Reduced air pressure in the lungs causes air to enter the lungs.
Exhaling reverses these steps.
Diagram: Ventilation diagram
What are Lungs?
The lungs are the main organs of the respiratory system.
In the lungs oxygen is taken into the body and carbon dioxide is breathed
out. The red blood cells are responsible for picking up the oxygen in the
lungs and carrying the oxygen to all the body cells that need it.
The red blood cells drop off the oxygen to the body cells, then pick up
the carbon dioxide which is a waste gas product produced by our cells.
The red blood cells transport the carbon dioxide back to the lungs and we
breathe it out when we exhale.
Diagram: Lungs diagram
Role of Lungs (Function)
1. Gaseous exchanges:
- Lung carries oxygen from the lungs to the site of tissue respiration for utilization and carriage of carbon dioxide from the site of the lung alveoli for elimination.
2.Metabolic Function.
3. Excretory Function.
Lung Defense Mechanism
- They humidify and cool or warm the inspired air, so that very hot or very cold air is modified close to the body temperature.
- Bronchial secretions contain secretory immunoglobulins that help to resist infection.
- The pulmonary alveolar macrophages are important components of the pulmonary mechanism. They are actively phagocyte and ingest inhaled bacteria actively phagocyte and ingest and small particles.
What is Respiratory Tract?
Group of organs which allow the entrance of air into the lungs and
exchange gases with the blood is called the respiratory tract. Basically
from the nose to the pulmonary alveoli are collectively known as
respiratory tract.
Diagram: Respiratory Tract diagram
Divisions of Respiratory Tract
Upper Respiratory Tract: From nose to the vocal fold-
- Nose
- Nasopharynx
- Oropharynx
- Larynx up to vocal folds
Diagram: Upper Respiratory Tract diagram
Lower Respiratory Tract: From vocal folds to the alveoli of the
lungs-
- Larynx below the vocal folds
- Trachea
- Two bronchi
- Bronchioles
- Terminal & Respiratory bronchioles
- Alveolar duct
Diagram: Lower Respiratory Tract diagram
Gaseous Exchange
Gaseous Exchange through Lungs
Diagram: Gaseous exchange diagram
Gas Exchange in Alveoli
Carbon dioxide concentration in metabolically active cells is much greater
than in capillaries, so carbon dioxide diffuses from the cells into the
capillaries. Water in the blood combines with carbon dioxide to form
bicarbonate.
In the alveoli capillaries, bicarbonate combines with a hydrogen ion
(proton) to form carbonic acid, which breaks down into carbon dioxide and
water. The carbon dioxide then diffuses into the alveoli and out of the
body with the next exhalation.
FAQs
Q) What is the full form of COPD?
A) The full form of COPD is Chronic Obstructive Pulmonary Disease.
Q) What is the full form of GERD?
A) The full form of GERD is Gastroesophageal Reflux Disease.
Q) How does the respiratory system help in oxygen delivery?
A) It brings in oxygen from the air and passes it to the blood. This
oxygen is then sent to body cells for energy.
Q) Why is respiratory system knowledge important for
Pharmaceutical Sales Representatives?
A) Because it helps them clearly explain how respiratory drugs work and
makes their discussions with doctors more accurate and credible.
Conclusion
Understanding The Human Respiratory System and Its Functions is
essential for every Pharmaceutical Sales Representative. When you know
the pathway of air and the basics of gas exchange, you can tie a drug’s
mechanism to its clinical effect and communicate that link in a
straightforward, professional way. This article lays out those core
concepts in plain, practical language to give a useful foundation for
clinical conversations and detailing.
Sarwar Hossain ✅
I am a travel enthusiast and sports-loving person. Education: BBA & MBA in Accounting.